state of matter (physical pharmacy)
TRANSCRIPT
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-