state of matter (physical pharmacy)

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States of Matter Aseel Samaro

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Page 1: State of matter (Physical Pharmacy)

States of Matter

Aseel Samaro

Binding Forces Between Molecules Solids and the Crystalline State Phase Equilibria and the Phase Rule

States of Matter

Objectives of the lecture

After completion of this chapter the students should be able toDescribe the solid state crystallinity solvates and polymorphismUnderstand phase equilibria and phase transitions between the three

main states of matterUnderstand the phase rule and its application to different systems

containing multiple components

Gases are compressible fluids Their molecules are widely separated Liquids are relatively incompressible fluids Their molecules are more tightly packed Solids are nearly incompressible and rigid Their molecules or ions are in close contact

and do not move

Comparison of Gases Liquids and Solids

In order for molecules to exist in aggregates in gases liquids and solids Intermolecular forces must exist

As two atoms or molecules are brought closer together the opposite charges and binding forces in the two molecules are closer together than the similar charges and forces causing the molecules to attract one another

The negatively charged electron clouds of molecules largely govern the balance (equilibrium) forces between the two molecules

Repulsive and Attractive Forces

Ideal Gas Equation

Boylersquos law P a (at constant n and T)1V

Charlesrsquo law V a T (at constant n and P)

Avogadrorsquos law V a n (at constant P and T)

P1V1

T1

=P2V2

T2

PV = nRTR is the gas constant

The conditions 0 0C and 1 atm are called standard temperature and pressure (STP)

Experiments show that at STP 1 mole of an ideal gas occupies 22414 L

PV = nRT

Gaseous state

R = PVnT

=(1 atm)(22414L)(1 mol)(27315 K)

R = 0082057 L bull atm (mol bull K)

9

What is the volume (in liters) occupied by 498 g of HCl at STP

PV = nRT

V = nRTP

T = 0 0C = 27315 K

P = 1 atm

n = 498 g x 1 mol HCl

3645 g HCl= 137 mol

V =1 atm

137 mol x 00821 x 27315 KLbullatmmolbullK

V = 307 L

Gaseous state

1 atm asymp 760001 mm-Hg

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 2: State of matter (Physical Pharmacy)

Binding Forces Between Molecules Solids and the Crystalline State Phase Equilibria and the Phase Rule

States of Matter

Objectives of the lecture

After completion of this chapter the students should be able toDescribe the solid state crystallinity solvates and polymorphismUnderstand phase equilibria and phase transitions between the three

main states of matterUnderstand the phase rule and its application to different systems

containing multiple components

Gases are compressible fluids Their molecules are widely separated Liquids are relatively incompressible fluids Their molecules are more tightly packed Solids are nearly incompressible and rigid Their molecules or ions are in close contact

and do not move

Comparison of Gases Liquids and Solids

In order for molecules to exist in aggregates in gases liquids and solids Intermolecular forces must exist

As two atoms or molecules are brought closer together the opposite charges and binding forces in the two molecules are closer together than the similar charges and forces causing the molecules to attract one another

The negatively charged electron clouds of molecules largely govern the balance (equilibrium) forces between the two molecules

Repulsive and Attractive Forces

Ideal Gas Equation

Boylersquos law P a (at constant n and T)1V

Charlesrsquo law V a T (at constant n and P)

Avogadrorsquos law V a n (at constant P and T)

P1V1

T1

=P2V2

T2

PV = nRTR is the gas constant

The conditions 0 0C and 1 atm are called standard temperature and pressure (STP)

Experiments show that at STP 1 mole of an ideal gas occupies 22414 L

PV = nRT

Gaseous state

R = PVnT

=(1 atm)(22414L)(1 mol)(27315 K)

R = 0082057 L bull atm (mol bull K)

9

What is the volume (in liters) occupied by 498 g of HCl at STP

PV = nRT

V = nRTP

T = 0 0C = 27315 K

P = 1 atm

n = 498 g x 1 mol HCl

3645 g HCl= 137 mol

V =1 atm

137 mol x 00821 x 27315 KLbullatmmolbullK

V = 307 L

Gaseous state

1 atm asymp 760001 mm-Hg

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 3: State of matter (Physical Pharmacy)

Objectives of the lecture

After completion of this chapter the students should be able toDescribe the solid state crystallinity solvates and polymorphismUnderstand phase equilibria and phase transitions between the three

main states of matterUnderstand the phase rule and its application to different systems

containing multiple components

Gases are compressible fluids Their molecules are widely separated Liquids are relatively incompressible fluids Their molecules are more tightly packed Solids are nearly incompressible and rigid Their molecules or ions are in close contact

and do not move

Comparison of Gases Liquids and Solids

In order for molecules to exist in aggregates in gases liquids and solids Intermolecular forces must exist

As two atoms or molecules are brought closer together the opposite charges and binding forces in the two molecules are closer together than the similar charges and forces causing the molecules to attract one another

The negatively charged electron clouds of molecules largely govern the balance (equilibrium) forces between the two molecules

Repulsive and Attractive Forces

Ideal Gas Equation

Boylersquos law P a (at constant n and T)1V

Charlesrsquo law V a T (at constant n and P)

Avogadrorsquos law V a n (at constant P and T)

P1V1

T1

=P2V2

T2

PV = nRTR is the gas constant

The conditions 0 0C and 1 atm are called standard temperature and pressure (STP)

Experiments show that at STP 1 mole of an ideal gas occupies 22414 L

PV = nRT

Gaseous state

R = PVnT

=(1 atm)(22414L)(1 mol)(27315 K)

R = 0082057 L bull atm (mol bull K)

9

What is the volume (in liters) occupied by 498 g of HCl at STP

PV = nRT

V = nRTP

T = 0 0C = 27315 K

P = 1 atm

n = 498 g x 1 mol HCl

3645 g HCl= 137 mol

V =1 atm

137 mol x 00821 x 27315 KLbullatmmolbullK

V = 307 L

Gaseous state

1 atm asymp 760001 mm-Hg

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 4: State of matter (Physical Pharmacy)

Gases are compressible fluids Their molecules are widely separated Liquids are relatively incompressible fluids Their molecules are more tightly packed Solids are nearly incompressible and rigid Their molecules or ions are in close contact

and do not move

Comparison of Gases Liquids and Solids

In order for molecules to exist in aggregates in gases liquids and solids Intermolecular forces must exist

As two atoms or molecules are brought closer together the opposite charges and binding forces in the two molecules are closer together than the similar charges and forces causing the molecules to attract one another

The negatively charged electron clouds of molecules largely govern the balance (equilibrium) forces between the two molecules

Repulsive and Attractive Forces

Ideal Gas Equation

Boylersquos law P a (at constant n and T)1V

Charlesrsquo law V a T (at constant n and P)

Avogadrorsquos law V a n (at constant P and T)

P1V1

T1

=P2V2

T2

PV = nRTR is the gas constant

The conditions 0 0C and 1 atm are called standard temperature and pressure (STP)

Experiments show that at STP 1 mole of an ideal gas occupies 22414 L

PV = nRT

Gaseous state

R = PVnT

=(1 atm)(22414L)(1 mol)(27315 K)

R = 0082057 L bull atm (mol bull K)

9

What is the volume (in liters) occupied by 498 g of HCl at STP

PV = nRT

V = nRTP

T = 0 0C = 27315 K

P = 1 atm

n = 498 g x 1 mol HCl

3645 g HCl= 137 mol

V =1 atm

137 mol x 00821 x 27315 KLbullatmmolbullK

V = 307 L

Gaseous state

1 atm asymp 760001 mm-Hg

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 5: State of matter (Physical Pharmacy)

As two atoms or molecules are brought closer together the opposite charges and binding forces in the two molecules are closer together than the similar charges and forces causing the molecules to attract one another

The negatively charged electron clouds of molecules largely govern the balance (equilibrium) forces between the two molecules

Repulsive and Attractive Forces

Ideal Gas Equation

Boylersquos law P a (at constant n and T)1V

Charlesrsquo law V a T (at constant n and P)

Avogadrorsquos law V a n (at constant P and T)

P1V1

T1

=P2V2

T2

PV = nRTR is the gas constant

The conditions 0 0C and 1 atm are called standard temperature and pressure (STP)

Experiments show that at STP 1 mole of an ideal gas occupies 22414 L

PV = nRT

Gaseous state

R = PVnT

=(1 atm)(22414L)(1 mol)(27315 K)

R = 0082057 L bull atm (mol bull K)

9

What is the volume (in liters) occupied by 498 g of HCl at STP

PV = nRT

V = nRTP

T = 0 0C = 27315 K

P = 1 atm

n = 498 g x 1 mol HCl

3645 g HCl= 137 mol

V =1 atm

137 mol x 00821 x 27315 KLbullatmmolbullK

V = 307 L

Gaseous state

1 atm asymp 760001 mm-Hg

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 6: State of matter (Physical Pharmacy)

Ideal Gas Equation

Boylersquos law P a (at constant n and T)1V

Charlesrsquo law V a T (at constant n and P)

Avogadrorsquos law V a n (at constant P and T)

P1V1

T1

=P2V2

T2

PV = nRTR is the gas constant

The conditions 0 0C and 1 atm are called standard temperature and pressure (STP)

Experiments show that at STP 1 mole of an ideal gas occupies 22414 L

PV = nRT

Gaseous state

R = PVnT

=(1 atm)(22414L)(1 mol)(27315 K)

R = 0082057 L bull atm (mol bull K)

9

What is the volume (in liters) occupied by 498 g of HCl at STP

PV = nRT

V = nRTP

T = 0 0C = 27315 K

P = 1 atm

n = 498 g x 1 mol HCl

3645 g HCl= 137 mol

V =1 atm

137 mol x 00821 x 27315 KLbullatmmolbullK

V = 307 L

Gaseous state

1 atm asymp 760001 mm-Hg

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 7: State of matter (Physical Pharmacy)

The conditions 0 0C and 1 atm are called standard temperature and pressure (STP)

Experiments show that at STP 1 mole of an ideal gas occupies 22414 L

PV = nRT

Gaseous state

R = PVnT

=(1 atm)(22414L)(1 mol)(27315 K)

R = 0082057 L bull atm (mol bull K)

9

What is the volume (in liters) occupied by 498 g of HCl at STP

PV = nRT

V = nRTP

T = 0 0C = 27315 K

P = 1 atm

n = 498 g x 1 mol HCl

3645 g HCl= 137 mol

V =1 atm

137 mol x 00821 x 27315 KLbullatmmolbullK

V = 307 L

Gaseous state

1 atm asymp 760001 mm-Hg

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 8: State of matter (Physical Pharmacy)

9

What is the volume (in liters) occupied by 498 g of HCl at STP

PV = nRT

V = nRTP

T = 0 0C = 27315 K

P = 1 atm

n = 498 g x 1 mol HCl

3645 g HCl= 137 mol

V =1 atm

137 mol x 00821 x 27315 KLbullatmmolbullK

V = 307 L

Gaseous state

1 atm asymp 760001 mm-Hg

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 9: State of matter (Physical Pharmacy)

P1V1

T1

=

P2V2

T2

Gaseous state

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 10: State of matter (Physical Pharmacy)

The critical temperature (Tc) is the temperature above which the gas cannot be made to liquefy OR is the temperature above which the liquid cannot longer exist

The critical pressure (Pc) is the minimum pressure required to liquefy a gas at its critical temperature

critical temperature (Tc) of water is 374degC or 647 K and its critical pressure is 218 atm

Liquefaction of Gases

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 11: State of matter (Physical Pharmacy)

SOLIDS amp CRYSTALLINE STATEPharmaceutical Drugs more than 80 are solid formulations

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 12: State of matter (Physical Pharmacy)

A crystalline solid possesses rigid and long-range order

In a crystalline solid atoms molecules or ions occupy specific (predictable) positions

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Solids and the crystalline state

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 13: State of matter (Physical Pharmacy)

Classification of Solids

Crystalline Amorphous

Amorphous

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 14: State of matter (Physical Pharmacy)

A unit cell is the basic repeating structural unit of a crystalline solid

latticepoint

Unit Cell Unit cells in 3 dimensions

At lattice points

bull Atoms

bull Molecules

bull Ions

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 15: State of matter (Physical Pharmacy)

The crystal lattice of sodium chloride NaCl

Na Cl

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 16: State of matter (Physical Pharmacy)

The various crystal forms are divide to basic 7 unit according to its symmetry

NaCl urea

iodine

sucrose Boric acid

Crystal forms

iodoform

Be3Al2(SiO3)6

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 17: State of matter (Physical Pharmacy)

CsCl ZnS CaF2

Ionic Crystalsbull Lattice points occupied by cations and anionsbull Held together by electrostatic attractionbull Hard brittle high melting pointbull Poor conductor of heat and electricity

Types of Crystals

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 18: State of matter (Physical Pharmacy)

diamondgraphite

carbonatoms

Covalent Crystalsbull Lattice points occupied by atomsbull Held together by covalent bondsbull Hard high melting pointbull Poor conductor of heat and electricity

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 19: State of matter (Physical Pharmacy)

Cross Section of a Metallic Crystal

nucleus ampinner shell e-

mobile ldquoseardquoof e-

Metallic Crystalsbull Lattice points occupied by metal atomsbull Held together by metallic bondsbull Soft to hard low to high melting pointbull Good conductors of heat and electricity

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 20: State of matter (Physical Pharmacy)

Some elemental substance such as C and S may exist in more than one crystalline form and are said to be allotropic which is a special case of polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphism

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 21: State of matter (Physical Pharmacy)

Polymorphism is the ability of a substance to exist in more than one crystal structure

Polymorphs when two crystals have the same chemical composition but different internal structure (molecular packing ndashmolecular conformation or and inter or intra molecular interactions)modifications or polymorphs or forms

Pseudo polymorphs different crystal forms have molecules of the same given substances and also contain molecules of solvent incorporated into a unique structure (solvates or hydrates (water))

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 22: State of matter (Physical Pharmacy)

diamond graphite

carbonatoms

High T and p

Diamond is metastable and converts very slowly to graphite

The most common example of polymorphism

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 23: State of matter (Physical Pharmacy)

Solid State Polymorphs

Mono-component systems Polymorphs

Multi-component systems

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 24: State of matter (Physical Pharmacy)

Cocrystal

The simplest definition of a cocrystal is a crystalline structure made up of two or more components in a definite stoichiometric ratio where each component is defined as either an atom ion or molecule

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 25: State of matter (Physical Pharmacy)

Principle of polymorphism

When the change from one form to another is reversible it is said to be enantiotropic

When the transition takes place in one direction onlymdashfor example from a metastable to a stable formmdashthe change is said to be monotropic

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 26: State of matter (Physical Pharmacy)

Solvates

Pharmaceutical synthesis include purification and crystallization residual solvent can be trapped in the lattice

This result in the formation of cocrystal or solvate

The presence of residual solvent may affect dramatically the crystalline structure of the solid depending on the type of inter molecular forces that the solvent may have with crystalline solid

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 27: State of matter (Physical Pharmacy)

Melting pointVapor pressureHardnessOptical electrical magnetic

propertiesColorIR spectraNMR spectra

Photochemical reactivityThermal stabilityFiltration and drying characteristicsDissolution rateBioavailabilityPhysical and chemical stability

Solubility and melting point are very important in pharmaceutical processes including dissolution and

formulation

Polymorphism

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 28: State of matter (Physical Pharmacy)

AMORPHOUS SOLIDS Solids that donrsquot have a definite geometrical shape are known as Amorphous Solids1 In these solids particles are randomly arranged in three dimension2 They donrsquot have sharp melting points3 Amorphous solids are formed due to sudden cooling of liquid4 Amorphous solids melt over a wide range of temperature

Amorphous Solid

An amorphous solid does not possess a well-defined arrangement and long-range molecular order

Amorphous substances as well as cubic crystal are isotropic that is they exhibit similar properties in all direction

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 29: State of matter (Physical Pharmacy)

The crystalline from of the antibiotic novobiocin acid is poorly absorbed and has no activity where the amorphous form is readily absorbed and therapeutically active due to different dissolution rate

Amorphous or crystalline amp therapeutic activity

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 30: State of matter (Physical Pharmacy)

General crystallization conditions 1048698Solvents ndashdifferent polarities 1048698Concentration of the solutions (super saturated saturated diluted) 1048698Cooling speed (quenching slow) 1048698Temperature (room or lower than room temperature)

Crystallization

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 31: State of matter (Physical Pharmacy)

Final Form

Granulation

Drying

Compaction

Tableting

Drug Product

API

Crystallization

Filtration

Drying

Milling

Bulk API

Stability

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 32: State of matter (Physical Pharmacy)

Polymorphism and Industry Pharmaceutical

Fluoxetine HCl the active ingredient in the antidepressant drug Prozac

co crystal which will have increased solubility compared to the crystalline form

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 33: State of matter (Physical Pharmacy)

Celecoxib

CELECOXIB is a nonsteroidal anti-inflammatory drug

However it was found that the higher bioavailability was shown by the amorphous state

The downfall of the amorphous state was its stability

This was due to the structural relaxation

This was enhanced by mixing it with polymers like PVP which helped in stabilizing the amorphous system (Piyush Gupta et al 2004 Piyush Gupta et al 2005)

A new solid state form was developed by Pharmacia

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 34: State of matter (Physical Pharmacy)

FurosemideTwo forms with significantly differing aqueous solubility and dissolution rateOral bioavailability compromised

Giron lists gt20 excipients that display polymorphism includingndash Lactose (anhydrous also monohydrate)ndash Aspartame (anhydrous hydrate forms)ndash Magnesium stearate (can affect lubrication of tablets)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 35: State of matter (Physical Pharmacy)

Bioavailability

The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 36: State of matter (Physical Pharmacy)

Bioequivalence

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 37: State of matter (Physical Pharmacy)

Carbamazepine

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 38: State of matter (Physical Pharmacy)

CHLORPROPAMIDEat least six polymorphic white or almost white crystalline powder It exhibits polymorphism Practically insoluble in water soluble in alcohol freely soluble in acetone and in dichlo-romethane dissolves in dilute solutions of alkali hydroxides Protect from light

blood-glucose-lowering drug

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 39: State of matter (Physical Pharmacy)

AIDS drug ritonavir

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 40: State of matter (Physical Pharmacy)

Theobroma oil (cacao butter ) is a polymorphic natural fat

Theobroma oil can exist in 4 different polymorphic forms of which only one is Stabile

1 Unstable gamma form melting at 18degC2 Alpha form melting at 22degC3 Beta prime form melting at 28degC4 Stable beta form melting at 345degC

This is important in the preparation of theobroma suppositories

If the oil is heated to a point where it is completely liquified (about 35 C) the crystals of the stable polymorph are destroyed amp the mass does not crystallize until it is cooled to 15 C

The crystals that form are unstable amp the suppositories melt at 24 C

Theobroma suppositories must be prepared below 33 C

Polymorphism and Industry Pharmaceutical

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 41: State of matter (Physical Pharmacy)

Polymorphism and Industry Pharmaceutical

Anhydrates together with salts form the majority of all drug formulationsAbout a half of all APIs used today are saltsSalts are stable and well soluble in polar solvents (first of all in water) because they contain ionic bondThere is one more essential advantage of salts ndash their solubility is a function of pH Since pH in the gastrointestinal tract (GIT) vary between 1-75

atorvastatin calcium trihydrateEach tablet contains Atorvastatin Calcium Trihydrate equivalent to Atorvastatin 20 mg

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 42: State of matter (Physical Pharmacy)

Phase Equilibria amp The Phase Rule

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 43: State of matter (Physical Pharmacy)

Phase diagram ndash Water

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 44: State of matter (Physical Pharmacy)

Phase Equilibrium A stable phase structure with lowest free-energy (internal energy) of a system and also randomness or disorder of the atoms or molecules (entropy)

Any change in Temperature Composition and Pressure causes an increase in free energy and away from Equilibrium thus forcing a move to another lsquostatersquo

Phase Equilibria amp The Phase Rule Definitions

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 45: State of matter (Physical Pharmacy)

A phase is defined as any homogeneous and physically distinct part of a system which is separated from other parts of the system by interfaces

A part of a system is homogeneous if it has identical physical properties and chemical composition throughout the part

A phase may be gas liquid or solid A gas or a gaseous mixture is a single phase Totally miscible liquids constitute a single phase In an immiscible liquid system each layer is counted as a separate phase Every solid constitutes a single phase except when a solid solution is formed A solid solution is considered as a single phase Each polymorphic form constitutes a separate phase

Phase Definition

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 46: State of matter (Physical Pharmacy)

1 Liquid water pieces of ice and water vapour are present together The number of phases is 3 as each form is a separate phase Ice in the system is a single phase even if it is present as a number of pieces

2 Calcium carbonate undergoes thermal decomposition The chemical reaction is CaCO3(s) CaO(s) + CO2 (g) Number of phases = 3 This system consists of 2 solid phases CaCO3 and CaO and one gaseous phase that of CO2

3 Ammonium chloride undergoes thermal decomposition The chemical reaction is NH4Cl(s) NH3 (g) + HCl (g) Number of phases = 2 This system has two phases one solid NH4Cl and one gaseous a mixture of NH3 and HCl

4 A solution of NaCl in water Number of phases = 1

bull Examples

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 47: State of matter (Physical Pharmacy)

The number of components of a system at equilibrium is the smallest number of independently varying chemical constituents using which the composition of each and every phase in the system can be expressed

Components

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 48: State of matter (Physical Pharmacy)

Counting the number of components 1 The sulphur system is a one component system All the phases

monoclinic rhombic liquid and vapour ndash can be expressed in terms of the single constituent ndash sulphur

2 A mixture of ethanol and water is an example of a two component system We need both ethanol and water to express its composition

bull Examples

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 49: State of matter (Physical Pharmacy)

An example of a system in which a reaction occurs and an equilibrium is established is the thermal decomposition of solid CaCO3

In this system there are three distinct phasesSolid CaCO3

Solid CaOGaseous CO2

Though there are 3 species present the number of components is only two because of the equilibrium CaCO3 (s) CaO(s) + CO2(g)

Any two of the three constituents may be chosen as the components

If CaO and CO2 are chosen then the composition of the phase CaCO3 is expressed as one mole of component CO2 plus one mole of component CaO

If on the other hand CaCO3 and CO2 were chosen then the composition of the phase CaO would be described as one mole of CaCO3 minus one mole of CO2

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 50: State of matter (Physical Pharmacy)

The degrees of freedom or variance of a system is defined as the minimum number of variables such as

temperaturepressureconcentrationwhich must be fixed in order to define the system completely

Degrees of freedom (or variance)

F = C P + 2

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 51: State of matter (Physical Pharmacy)

1 A gaseous mixture of CO2 and N2 Three variables pressure temperature and composition are required to define this system This is hence a trivariant system

2 A system having only liquid water has two degrees of freedom or is bivariant Both temperature and pressure need to be mentioned in order to define the system

3 If to the system containing liquid water pieces of ice are added and this system with 2 phases is allowed to come to equilibrium then it is an univariant system

Only one variable either temperature or pressure need to be specified in order to define the systemIf the pressure on the system is maintained at 1 atm then the temperature of the system gets automatically fixed at 0oC the normal melting point of ice

bull Examples

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 52: State of matter (Physical Pharmacy)

Phase Equilibria amp The Phase Rule

A phase diagram (Equilibrium Phase Diagram) summarizes the conditions at which a substance exists as a solid liquid or gas

OR It is a ldquomaprdquo of the information about the control of phase structure of a particular material system

The relationships between temperature and the compositions and the quantities of phases present at equilibrium are represented

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 53: State of matter (Physical Pharmacy)

F = C P + 2The phase rule

The phase rule JW Gibbs formulated the phase rule which is a general relation

between the variance F the number of component C and the number of phases P at equilibrium for a system of any composition

For a system in equilibrium

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 54: State of matter (Physical Pharmacy)

Phase Rule relation to determine the least number of intensive variable that can be changed without changing the equilibrium state of the system or alternately

The least number required to define the state of the system which is called degree of freedom F

Intensive variable independent variable that do not depend on the volume or the size egTemp pressure

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 55: State of matter (Physical Pharmacy)

Independent chemical species which comprise the system These could be Elements Ions Compounds

Eg Au-Cu system Components rarr Au Cu Ice-water system Component rarr H2O

Al2O3 ndash Cr2O3 system Components rarr Al2O3 Cr2O3

Component the smallest number of constituent by which the composition of each phase in the system at equilibrium can be expressed in form of chemical formula or equation

Phase Equilibria amp The Phase RuleComponents of a system

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 56: State of matter (Physical Pharmacy)

The number of phases in a system is denoted P

(a)A gas or a gaseous mixture is a single phase P=1

(b) For a solid system an alloy of two metals is a two-phase system (P=2) if the metals are immiscible but a single-phase system (P=1) if they are miscible---a homogeneous mixture of the two substances---is uniform on a molecular scale

(c) For a liquid system according to the solubility to decide whether a system consists of one phase or of two For example a solution of sodium chloride in water is a single phase A pair of liquids that are partially miscible or immiscible is a two-phase system(P=2)

Oil in water

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 57: State of matter (Physical Pharmacy)

Degrees of Freedom = What you can control What the system controls

F = C + 2 P

Can control the no of components added and P amp T

System decided how many phases to produce given the

conditions

A way of understanding the Gibbs Phase RuleThe degrees of freedom can be thought of as the difference between what you (can) control and

what the system controls

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 58: State of matter (Physical Pharmacy)

F degree of freedom the least number of intensive variable that must be fixed (known) to describe the system completely

Degree of freedom (or variance) F is the number of variables (T p andor composition) that can be changed independently without changing the phases of the system

a) At the triple pointP = 3 (solid liquid and gas)

C= 1 (water)P + F = C + 2

F = 0 (no degree of freedom)

b) liquid-solid curveP = 2

2+F = 1 + 2F= 1

One variable (T or P) can be changed

c) LiquidP =1

So F =2Two variables (T and P) can be varied independently

and the system will remains a single phase

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 59: State of matter (Physical Pharmacy)

One-component systemsPhase diagram of water

P (

atm

)

Critical point

374

1

=100=0O--Triple point

0006

218

Curve O -CSublimation

Deposition

Curve O-AVaporizationCondensation

Curve O -BMelting

Freezing

F = C P + 2

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 60: State of matter (Physical Pharmacy)

F = C P + 2

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 61: State of matter (Physical Pharmacy)

Phase Diagram of Carbon Dioxide

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 62: State of matter (Physical Pharmacy)

Condensed system System in which the vapor phase is ignored and only the solid andor liquid phases are considered

Two component system For two component system F can be 3 (3D model is needed) eg T p

and concentration usually we fix p = 1atm the vapor phase is neglected and F is reduced to 2

For three component system the pressure and temperature are fixed

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 63: State of matter (Physical Pharmacy)

Phenol water phase diagram

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 64: State of matter (Physical Pharmacy)

eg for point d (24)

Two component system containing liquid phase

Tie Line bc line The line at which the system at equilibrium will separate into phases of constant composition termed lsquoconjugate phasesrsquo

Lever Rule a way to calculate the proportions of each phase present on a phase diagram in a two phase field (at a given temperature and composition)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 65: State of matter (Physical Pharmacy)

eg for point d (24)

For every 10 g of liquid system in equilibrium in point d

75 g phase A25 g phase B

ExampleMixed 24g phenol +76g water T 50degC

equilibrium75 g phase A 25 g phase B

11 phenol 63 phenol

011 times75 g=825 g phenol

063 times25 g=1575 g phenol

water rich phasecontains water+ phenol(11)

Phenol rich phasecontains Phenol (63)+ water

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 66: State of matter (Physical Pharmacy)

The Critical Solution Temperature CST

Is the maximum temperature at which the 2-phase region exists (or upper consolute temperature)

In the case of the phenol-water system this is 668oC (point h)

All combinations of phenol and water gt CST are completely miscible and yield 1-phase liquid systems

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 67: State of matter (Physical Pharmacy)

Systems Showing a Decrease in Miscibility with Rise in Temperature

A few mixtures exhibit a lower critical solution temperature (low CST) eg triethylamine plus water The miscibility with in temperature

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 68: State of matter (Physical Pharmacy)

Systems Showing Upper and Lower CSTs

The miscibility with temp

a certain temperature miscibility starts to again with further in temperature

Closed-phase diagram ie nicotine-water system

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 69: State of matter (Physical Pharmacy)

A salol B thymol

53

Two component system containing solid and liquid phase (Eutectic Mixtures)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 70: State of matter (Physical Pharmacy)

A salol B thymol

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 71: State of matter (Physical Pharmacy)

EMLAreg (lidocaine 25 and prilocaine 25) Cream

EMLA Cream (lidocaine 25 and prilocaine 25) is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 11 by weight This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals

Eutectic mixture Pharmaceutical Application

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 72: State of matter (Physical Pharmacy)

Triangular Diagrams for three ndash component systems

Three component system

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 73: State of matter (Physical Pharmacy)

Birzeit University Physical Pharmacy PHAR 323 Dr Hani Shtaya

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered
Page 74: State of matter (Physical Pharmacy)

1 Binding Forces Between Molecules2 Repulsive and Attractive Forces3 The Gaseous State The Ideal Gas Law Liquefaction of Gases Aerosols4 Solids and the Crystalline State Crystalline Solids Polymorphism Solvates Amorphous Solids5 Phase Equilibria and the Phase Rule Phase Rule Systems Containing One Component Condensed System Two-Component Systems Containing Liquid Phases Two-Component Systems Containing Solid and Liquid Phases Eutectic Mixtures Rules Relating to Triangular Diagrams

Topics that we have covered

  • States of Matter
  • States of Matter (2)
  • Objectives of the lecture
  • Comparison of Gases Liquids and Solids
  • Slide 5
  • Repulsive and Attractive Forces
  • Ideal Gas Equation
  • Gaseous state
  • Slide 9
  • Gaseous state (2)
  • Liquefaction of Gases
  • Slide 12
  • SOLIDS amp CRYSTALLINE STATE Pharmaceutical Drugs more than 80
  • Solids and the crystalline state
  • Classification of Solids
  • Slide 16
  • Slide 17
  • Crystal forms
  • Types of Crystals
  • Slide 20
  • Slide 21
  • Polymorphism
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Cocrystal
  • Principle of polymorphism
  • Solvates
  • Polymorphism (2)
  • Amorphous Solid
  • Amorphous or crystalline amp therapeutic activity
  • Slide 33
  • Slide 34
  • Polymorphism and Industry Pharmaceutical
  • Celecoxib
  • Furosemide
  • Bioavailability
  • Slide 39
  • Slide 40
  • Bioequivalence
  • Slide 42
  • Carbamazepine
  • Slide 44
  • AIDS drug ritonavir
  • Slide 46
  • Slide 47
  • Phase Equilibria amp The Phase Rule
  • Phase diagram ndash Water
  • Phase Equilibria amp The Phase Rule Definitions
  • Phase Definition
  • Examples
  • Components
  • Examples
  • Slide 55
  • Degrees of freedom (or variance)
  • Examples (2)
  • Phase Equilibria amp The Phase Rule
  • The phase rule
  • Slide 60
  • Phase Equilibria amp The Phase Rule (2)
  • The number of phases in a system is denoted P
  • Slide 63
  • Slide 64
  • One-component systems
  • Slide 66
  • Slide 67
  • Slide 68
  • Slide 69
  • Slide 70
  • Two component system containing liquid phase
  • Slide 72
  • The Critical Solution Temperature CST
  • Systems Showing a Decrease in Miscibility with Rise in Temperat
  • Systems Showing Upper and Lower CSTs
  • Two component system containing solid and liquid phase (Eutecti
  • Slide 77
  • Eutectic mixture Pharmaceutical Application
  • Three component system
  • Slide 80
  • Topics that we have covered