chapter - 5 development and evaluation of alfuzosin...

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CHAPTER - 5

DEVELOPMENT AND EVALUATION OF ALFUZOSIN

ER TABLETS

5.1 MATERIALS AND EQUIPMENTS

Table 5.1: List of materials used in research work

Name of the Material Manufacturer

Alfuzosin Hydrochloride

Ph.Eur

Dr. Reddys laboratory, Hyderabad,

India.

Doxazosin Mesylate Ph.Eur Clearsynth labs ,India.

Microcrystalline Cellulose

( Avicel PH-101) USP/NF

FMC Bio Polymer, Ireland.

Ammonio Methacrylate

co-polymers (Eudragit RLPO)

USP/NF

Evonik industries, Germany.

Povidone(PVP K-30) USP/NF ISP Sales (UK) Limited.

Partially Pregelatinized Starch

(Starch 1500) USP/NF

Colorcon ,Goa

Hypromellose (Methocel

K100M) USP/NF

Dow chemical company, USA

Gaur Gum 8000 cps Lucid Colloids, Mumbai

Colloidal Silicon Dioxide

USP/NF

Evonik industries, Germany.

Magnesium Stearate USP/NF Ferro corporation, Cleveland.

Acetonitrile (AR Grade) Merck Specialties Pvt. Ltd, Mumbai.

Triethylamine (AR Grade) Merck Specialties Pvt. Ltd, Mumbai.

Potassium dihydrogen

Orthophosphate (ARGrade)

Merck Specialties Pvt. Ltd, Mumbai.

Hydrochloric acid (ARGrade) Merck Specialties Pvt. Ltd, Mumbai.

Orthophosphoric acid (AR

Grade)

Merck Specialties Pvt. Ltd, Mumbai.

56

Potassium coated EDTA

Tubes

Merck specialities Pvt.Ltd,

Rabbits weighing 2.8 – 3.2 Kg Saastra College of Pharmaceutical

Education and Research, Nellore

Table 5.2: List of equipments used in the research work

Equipment Name Manufactured By

Electronic Weighing Balance Mettler Toledo (AB104), Germany.

Rapid mixer granulator Diasona, Bombay.

Hot air oven Innovative instruments, Delhi.

Double cone blender Shakthi engnering, Ahemadabad

Sieves Jayant Scientific Ind., Bombay

Compression Machine (8 Station) Cadmach, Ahemadabad

Digital Vernier Calipers Mitutoyo (CD-8CSX), China.

Friability Apparatus Electrolab EF – 2W, Mumbai.

Hardness Tester Dr. Schleuniger (6D), Germany.

Dissolution Apparatus TDT-08L, Electrolab, Mumbai.

Sonicator Power sonic 505, India.

HPLC Waters, USA.

FT-IR Perkin Elmer,Japan.

Vortex Mixer Spinex, India.

Stability Chamber Mack, Mumbai.

DSC DSC21, Mettler Toledo, USA.

UV visible spectrophotometer Analytikjena Specord 210

Overhead 3-blade medium duty

stirrer Remi stirrer, Mumbai, India.

Cyclomixer Remi Instruments, Mumbai, India.

Multifuge Centrifuger Heraus, Germany.

57

5.2 ANALYTICAL METHODS

There are several reported methods for the estimation of

alfuzosin available in the literature, those are UV, Colorimetry, HPLC

&LC-MS methods.

In the present investigation we have develop a modified

Ultraviolet spectroscopic method for the estimation of alfuzosin

hydrochloride for dissolution samples*.HPLC method was developed

for estimation of drug content (Assay)*.The analytical methods (i.e

dissolution and assay) of alfuzosin hydrochloride extended release

tablets not published in official pharmacopeia.(i.e IP, BP&USP)

* The methods was developed on the basis of development and

validation of UV spectrophotometric method for estimation of alfuzosin

by Adsule Prajakta V et al.,40 for dissolution samples and New RP

HPLC method development and validation of assay for alfuzosin in

tablet dosage form by K.S.Bharathkumar et al.,44 for uniformity of

content and assay samples.

A new High performance liquid Chromatographic method was

developed and validated for the estimation of alfuzosin in rabbit

plasma.

5.2.1 Method development

The solubility of the Alfuzosin was tested in different dissolution

media like 0.01N HCl, pH 4.5 Acetate buffer, pH 6.8 phosphate

buffers, pH 10.0 phosphate buffer and Purified water. Based on the

solubility data dissolution media 0.01N HCl was selected as media

with 900mL of volume, maintained at 37 ± 0.5°C and USP Apparatus-

II (Paddle). Samples were collected at appropriate time intervals from

58

dissolution vessels and diluted the samples and measured the

absorbance at 245nm using UV-Visible spectrophotometer and

calculated using standard calibration curve.

5.2.1.1 Standard calibration curve of Alfuzosin

5.2.1.1.1 Preparation of 0.01N HCl

8.5mL of Hydrochloric Acid was diluted with water to 10 Litres.

5.2.1.1.2 Preparation of standard stock solution

25.0 mg of Alfuzosin HCl weighed in to 50ml volumetric flask

and made up the volume with 0.01N HCl. 2ml of this solution further

diluted to 100ml with 0.01N HCl.

5.2.1.1.3 Preparation of standard Calibration Curve

From the standard stock solution serial dilution were done to

obtain solutions ranging from 0.5µg/mL to 6.0µg/mL, i.e. from 10% to

120% with respect to sample concentration. The absorbance of above

solutions was measured at wavelength of 245nm using UV-Visible

spectrophotometer (Analytikjena Specord 210), against dissolution

media as blank.

The absorbance values of standard curve was represented in

Table 5.3 and a graph was plotted of concentration v/s absorbance

which was shown in Fig. 5.1

59

Table 5.3: Standard Calibration curve values of Alfuzosin

The linear equation was y = 0.1381 x - 0.0001

Where x is concentration and y is the peak absolute area.

The correlation coefficient was r = 1.000, indicating good linearity.

Figure:5.1 Standard Calibration curve of Alfuzosin

y = 0.1381x 0.0001 R² = 1.000

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 1 2 3 4 5 6 7

Ab

sorb

ance

Concentration (µg/mL)

Concentration in µg/mL Absorbance

0.5 0.0691

1.0 0.1354

2.0 0.2761

3.0 0.4201

5.0 0.6882

6.0 0.8281

Slope 0.1381

Intercept 0.0001

Correlation Coefficient 1.000

60

5.2.2 Assay by HPLC

5.2.2.1 Method development

Different columns, mobile phases, flow and column

temperatures were tested in the development of the analytical method.

C-8 and C-18 columns of the same length, different lengths and

diameters were also tested and pH of buffer variations from 3.0 to 6.5

were also tested by keeping all parameters and conditions were

constant (0.8 mL/min., injection volume of 20μL,temperature at

25°C). Then the mobile phases with different buffer concentrations

and organic content were also tested by keeping the all parameters

and conditions were constant. Finally we got the good

chromatographic peak with more than 5000 theoretical plates, tailing

factor of less than 2.0 and Relative standard deviation of less than

2.0% for six replicate standard injections.

61

5.2.2.1.1 Preparation of Dilute Orthophosphoric acid

9.3mL of 82%-Ortho phosphoric acid was diluted to 100mL with

water.

5.2.2.1.2 Preparation of Buffer

2.72g of Potassium dihydrogen phosphate weighed and

transferred into a beaker containing 1000mL of water. Sonicated to

dissolve and 2.0mL of Triethylamine was added and mixed well. pH of

the solution was adjusted to 3.0 ± 0.05 with diluted orthophosphoric

acid. Solution was filtered through 0.45μ membrane filter.

5.2.2.1.3 Preparation of mobile phase

Prepare and degassed the mixture of buffer and acetonitrile in the

ratio of 75:25%v/v.

Diluent: Mobile phase was used as diluent.

5.2.2.1.4 Chromatographic conditions

HPLC System : Waters Alliance 2695 with empower software

Column : C18, 150×4.6mm 5µ or equivalent

Flow rate : 0.8ml/min

Detection : 245nm

Injection volume : 20µL

Column temperature : 25°C

Run time : 10min

62

5.2.2.1.5 Standard preparation

50.0mg of Alfuzosin Hydrochloride standard weighed accurately

and transfer into a 200.0ml volumetric flask, dissolved and diluted

with diluent.5.0ml of this solution was transferred in to 100ml of

volumetric flask, dilute to volume with diluent and mixed well.

5.2.2.2 Method validation76

The system suitability linearity, accuracy and precision of the

method were validated.

The specificity of test method by HPLC demonstrated that the

excipients from tablets do not interfere with the analytic peak. The

linearity of the method was tested in the concentration range

1.26µg/mL to 15.08µg/mL (10.0% to 120.0%). For accuracy of the

method, standard drug was spiked from 70.0% to 130.0% and

recovery was found to be 99.2% to 100.9% and RSD 0.8%. The

precision of the method was checked were found to be relative

standard deviation 0.9%.

63

Table 5.4: Linearity

Figure 5.2: Alfuzosin assay Linearity graph

y = 331585.1 x 13706.8 R² = 0.999

0

200000

400000

600000

800000

1000000

1200000

1400000

1600000

1800000

0 10 20 30 40 50 60 70

Pe

ak a

rea

Concentration (µg/mL)

Concentration in % Concentration in

µg/ml

Peak Area

10 1.26 402135

20 2.51 839456

40 5.03 1690564

60 7.54 2584154

100 12.56 4125891

120 15.08 5023154

Slope 331585.1

Intercept 13706.8

Correlation Coefficient 0.999

64

Table 5.5: Accuracy/recovery

Table 5.6: Precision

S.No. % Assay

1 99.0

2 101.0

3 99.0

4 99.5

5 98.6

6 99.0

Avg 99.4

SD 0.86

% RSD 0.9

Figure 5.3: Alfuzosin Assay Standard

Level Actual weight added in mg

% in mg recovery

% recovery

70% 7.02 7.00 99.7

100% 10.04 9.96 99.2

130% 12.98 13.10 100.9

Mean 99.9

SD 0.8

RSD 0.8

65

5.3 PRE-FORMULATION

5.3.1 Solubility Analysis

The solubility of Alfuzosin Hydrochloride was determined in

different media as follows.

1. 0.01N HCl

2. pH 4.5 Acetate buffer

3. pH 6.8 phosphate buffer

4. pH 10.0 phosphate buffer

5. Purified Water

1.0 gm amount of the drug was weighed and transfer to 25 mL

volumetric flasks. To each of the volumetric flasks above mentioned

media were added and shaken well. The volume was made up to

volume with same media the samples were kept in constant water

bath shaker for 24 hours at temperature of 37 °C. After 24 hours the

samples were removed from bath, equilibrated for 1 hr. then the

samples were filtered through 0.45 μm filter. The dissolved drug was

measured using UV visible spectrophotometer at 245 nm after

suitable dilutions.

5.3.2 Compatibility Studies

5.3.2.1 Differential Scanning Calorimetry

Differential Scanning Calorimetry of active ingredient and

polymers were studied to investigate the compatibility of the both

materials when mixed together by observing any changes occur in

melting points of the drug. The test was performed at a rate of 5°C

66

min-1 from 25°C to 300°C temperature range under nitrogen flow of 25

ml min-1 using differential scanning calorimeter.

5.3.2.2 Fourier Transform Infra-Red (FT-IR) spectral analysis

Fourier–Transformed Infrared (FT–IR) spectrums of Alfuzosin

with HPMC K100M ,Guar gum 8000cP, Eudragit RLPO and Povidone

K-30 performed individually and in combinations at range of 400 to

4000 cm-1 and the resolution was 1 cm-1 using Fourier Transform

Infrared (FTIR) spectrophotometer, (Perkin Elmer, spectrum-100,

Japan )using the KBr disk method (2 mg sample in 200 mg KBr).

This spectral test was used to check the compatibility of

Alfuzosin Hydrochloride with the selected polymers. The spectrums

were shown in Fig. 5.15 to 5.31.

67

5.4 PREPARATION OF MATRIX TABLETS

5.4.1 Preparation of matrix tablets containing Alfuzosin

The wet granulation technique was chosen to prepare matrix

tablets. The compositions of the formulations were given in Table 5.7.

Matrix tablets were prepared using below technique.

Step1.Required quantity of Alfuzosin, retardant (HPMC K100 M or

Guar gum 8000 cps or Eudragit RLPO) and other excipients

(Microcrystalline Cellulose (AVCEL PH 101, Pregelatinized Starch and

Povidone) were weighed and sifted through 40# sieve.

Step 2. Step1 material was mixed in rapid mixing granulator (RMG)

for 15min and blend was granulated using purified water as the

granulating agent.

Step 3. The wet granules were sifted through 14 # sieve and dried in

hot air oven at inlet temperature of 60 ± 5°C till the moisture comes

below 3%w/w.

Step 4. The dried granules were sieved through 20 # sieve and

lubricated with Magnesium stearate and colloidal silicon dioxide

(previously shifted through # 40 mesh) for about 5 min in a double

cone blender.

Step 5. The lubricated granules were compressed into tablets using

8.8 mm round shaped with standard concave punches.(compression

machine 8 station ).

68

Table5.7: Composition of matrix tablet containing Alfuzosin

Name of ingredient mg/tablet

ALF/01 ALF/02 ALF/03 ALF/04 ALF/05 ALF/06 ALF/07 ALF/08 ALF/09 ALF/10 ALF/11 ALF/12

Alfuzosin HCL 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00

Microcrystalline Cellulose

Avicel PH 101 158.00 245.50 204.00 90.50 187.00 134.00 204.00 194.00 194.00 184.00 174.00 104.00

Eudragit RLPO 120.00 -- --- --- -- --- --- --- --- --- --- ---

Povidone K -30 9.00 --- --- --- -- --- --- --- --- --- --- ---

Starch 1500 --- --- --- 15.00 --- --- --- --- --- --- --- ---

Hydroxypropyl methyl

cellulose K100M --- --- -- --- 100.00 150.00 100.00 105.00 100.00 110.00 115.00 150.00

Guar gum 8000 cP --- 40.00 80.00 180.00 --- - 30.00 35.00 40.00 40.00 45.00 80.00

Purified Water QS QS QS QS QS QS QS QS QS QS QS QS

Collodial silicone dioxide --- 1.50 2.00 1.50 --- 2.00 2.00 2.00 2.00 2.00 2.00 2.00

Magnesium Stearate 3.00 3.00 4.00 3.00 3.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00

Tablet Weight 300.00 300.00 300.00 300.00 300.00 300.00 350.00 350.00 350.00 350.00 350.00 350.00

69

5.5 EVALUATION OF TABLETS

5.5.1 Evaluation of physical parameters for granules

5.5.1.1 Flowability78,79

Flowablility of lubricated granule were tested by using Bulk

density, Tap density, Compressibility, Hausner’s ratio and Angle of

repose. Formulas are as below.

The bulk density of prepared granules were determined by

three-tap method. Weighed quantity (15gm of granules) was carefully

introduced in to a 100mL graduated cylinder. The cylinder was

dropped on to a hard wood surface 3 times from a height of 2.5cm at

an interval of 2sec. The bulk density was obtained by dividing weight

of the sample by volume of the sample.

The tap density is the ratio of weight of the dry its tapped

volume. The above weighed quantity of granules was placed on tapped

density tester (Electrolab Model:ETD-1020) and subjected to USP –

Type II method i.e, 250 drops per minute and drop height is 3 mm ±

10%. The volume of the powdered weight is measured after increment

of 250 drops until the difference of last two values mean is zero.

Bulk Density =

Tapped Density =

Compressibility Index (%) and Hausner’s Ratio Can calculated

by using the following formulas.

Compressibility Index (%) =

×100

Hausner’s Ratio =

70

Angle of repose

Take funnel stand with smooth base, keep the funnel and

adjust the funnel height such a way that the distance between the

powder pile and funnel should be approximately 2-4 cm. keep the

graph paper on base, hold the funnel orifice, pore the powder and

leave the orifice to fall down. Find the height (H) of the cone of powder

and circle of the powder carefully. Find out the angle of repose using

following equation:

Where, α is angle of the repose.

“H” is height of the powder cone

“R” is radius of the circle.

Table 5.8: Scale of flowability79

Flow Property Compressibility

Index

Hausner

Ratio

Angle of

Repose

Excellent ≤ 10 1.00-1.11 25-30

Good 11-15 1.12-1.18 31-35

Fair 16-20 1.19-1.25 36-40

Passable 21-25 1.26-1.34 41-45

Poor 26-31 1.35-1.45 46-55

Very poor 32-37 1.46-1.59 56-65

Very, Very poor >38 >1.60 >66

71

5.5.2 Evaluation of physical parameters for Tablets

5.5.2.1 Uniformity of Weight80

Ten tablets were selected randomly from each batch and

weighed individually and determine the average weight, then check for

weight variation. The average weight of tablet with % deviation as per

Indian pharmacopeia was represented in table

Table 5.9: Average weight of tablet with % deviation as per Indian

Pharmacopeia.

Average weight of Tablet % Deviation

80 mg or less 10

< 80 mg and < 250 mg 7.5

< 250 mg 5.0

5.5.2.2 Thickness

Thickness of the tablets was checked using digital vernier

calipers by placing the tablet in between the two jaws.

5.5.2.3 Hardness81

Hardness is main criteria for tablets and should have enough to

withstand mechanical stress like coating, packaging, shipment, and

handling by the consumer. The crushing strength test of tablet

diametrically was performed on 10 tablets from each formulation by

using Dr.Schleuniger, Hardness tester.

72

5.5.2.4 Friability82

The friability test is to evaluate the ability of the tablet to

withstand abrasion in coating, packaging, handling and shipping.

Friability of each formulation tested using 20 tablets was

determined using a Roche type friability tester.20 tablets were

weighed, transferred to friabilator and performed the test with 100

rotations at speed of 25 rpm. After completion of rotations tablets

were removed, dedusted and weighed. Friability of tablet should not

be more than 1.0 %. Friability percentage was calculated using the

following equation:

× 100

5.5.3 Drug content by HPLC

Accurately weighed 20 tablets and determined the average tablet

weight in mg. Tablets were crushed into fine powder. Weighed the

sample equivalent to 10.0mg of Alfuzosin and transferred it into

individual 200ml volumetric flask with the aid of 120ml diluent.

Solution was sonicated for 15min, dissolved and diluted to volume

with diluent. Portion of sample was centrifuged for about 15min prior

to dilution. 5.0ml of sample solution was transferred into individual

20.0ml volumetric flask, made up the volume with diluent and mix

well. Alfuzosin was estimated by HPLC using developed method

step:5.2.2.

http://www.pharmainfo.net/friability-test

73

5.5.4 Uniformity of drug content test77

Ten tablets were selected randomly, weigh the tablet

individually and place it into individual 200ml volumetric flask with

the aid of 120ml diluent. Solution was sonicated for 15min, dissolved

and diluted to volume with diluent. Portion of sample was centrifuged

for about 15min prior to dilution. 5.0ml of sample solution was

transferred into individual 20.0ml volumetric flask, made up the

volume with diluent and mix well and inject to the HPLC System as

followed as per assay method. (5.2.2)

5.5.5 In-vitro Dissolution Study: (By UV)

Dissolution Parameters

Medium : 0.01N HCl

Volume : 900mL

Apparatus : USP-II (Paddle)

Revolutions(RPM) : 100

Temperature : 37 ± 0.5° C

Time Points : 1,2,3,6,12 and 20 hours

Lambda √ : 245nm

5.5.5.1 Test Solution

All the bowls were filled with 900 mL of dissolution medium and

maintained at 37±0.5 °C. Dropped one tablet in to each dissolution

vessel and start the dissolution test. 10.0 ml of aliquot were

withdrawn at specific time intervals and same quantity of fresh

dissolution media was replaced. Aliquots were filtered through 0.45 μ

(Millipore) nylon membrane filter.5ml of this solution was diluted to

74

10ml with dissolution medium .Samples were estimated by developed

method step: 5.2.1.

5.5.6 Effect of Hardness on dissolution

To study the effect of hardness on the tablet formulation, we

have compressed the formulation (B.No: ALF/10) at different hardness

levels i.e low hardness (8.1 to 9.3kp), optimum hardness (10.7 to 12.2

kp), high hardness (14.4 to 15.7 kp). The dissolution studies were

performed arrive the effect of the hardness on the drug release.

All the samples were analysing for in-vitro drug release by using same

mentioned method (5.2.1).

For comparison, marketed samples also analysed by using same

method (5.2.1)

5.5.7 Statistical approach to difference and similar factor83

The model independent method is most suitable for dissolution

profile comparison when 3 to 4 or more dissolution time points are

available.

Statistical models such as Difference factor (f1) and similar

factor (f2) both were constructed for optimized batch and marketed

product dissolution profile by using following equations. Difference

factor measures the % difference between 2 curves at each time point

and the relative error between the two curves, similarity factor is a

measurement of % dissolution similarity between the two curves.

Difference Factor f1={[∑t=1n (Rt-Tt)]/[ ∑t=1

n Rt]} x 100

Similar Factor f2=50xlog{[1+(1/n)∑t=1n (Rt-Tt)2]-0.5 x 100

75

Where,

n is number of time points.

R(t) is the mean % drug dissolved of Marketed product at time t.

T(t) is the mean % drug dissolved of test product.

f1 value should be close to 0 (0 to 15) to prove the both the

formulations are not different.

f2value should be between 50 to 100 to prove the both the

formulations are similar.

5.5.8 Kinetic modeling system for In-vitro release84

5.5.8.1 Zero Order

Drug dissolution from dosage forms that do not disaggregate

and release the drug slowly (a constant release rate) can be

represented by zero order equation. To study the release kinetics, in

vitro data of drug release studies were plotted as cumulative amount

of percentage drug released versus time. It describes the rate of drug

release is independent of the concentration of dissolved substance.

C = Kot

Where, Ko is zero-order rate constant expressed in units of

concentration/time and t is the time.

Application: This equation can be used to describe the drug

dissolution of matrix tablets with low soluble drugs, osmotic systems

andtransdermal systems,

5.5.8.2 First Order

This model useful in the determination of drug absorption

and/or elimination. Drug release depending on the concentration.

76

LogC=LogCo-kt /2.303

Where, Co = The initial concentration of drug and K is first order

constant.

Application: This equation can be used to describe the drug release in

porous matrices those containing water-soluble drugs.

5.5.8.3 Erosion model85

This equation defines the drug release based on erosion alone.

Q = 1-(1-k3t) 3

Where, Q is the fraction of drug released at time t, k3 is the release

rate constant. Thus, a plot between [1-(1-Q) 1/3] against time will be

linear if the release obeys erosion equation.

5.5.8.4 Korsmeyer-Peppas model

To find the drug release mechanism first 60% drug release data

were fitted in Korsmeyer-Peppas model, which described drug release

from a polymeric system equation. To study release kinetics, in vitro

drug release data was plotted as log cumulative % drug release versus

log time.

Mt / M∞= Ktn

Where Mt / M∞ =a fraction of drug released at time t,

K = The release rate constant and n is the release exponent. The n

value is used to characterize different mechanism of drug release for

cylindrical shaped matrices.

5.5.8.5 Higuchi’s Model

The first mathematical model which describes drug release from

a matrix system proposed by Higuchi in 1961. It is applicable for

77

planar systems initially; it was then extended to different geometrics

and porous systems.

Q=KH x T1/2

KH = The Higuchi dissolution constant

The values of cumulative percentage drug release versus square root

of time.

Application: This can be used to describe the drug release from matrix

tablets with water soluble drugs and transdermal systems.

5.6 Stability Studies86

Stability study of selected formulation was tested according to

international conference of harmonization guidelines. The tablets was

stored in Alu-Alu blister for 3 months in stability chamber at 40°C ±

2°C & 75% ± 5 % RH. Stability samples were tested for Physical, drug

content and in vitro dissolution.

78

5.7 RESULTS

5.7.1 Solubility Analysis

Solubility of Alfuzosin in different media at 37 °C ± 0.5 °C.

Table 5.10: Solubility of Alfuzosin

Media Solubility “mg/mL”

pH 2.0 0.01N HCL 192( mg/mL)

pH 4.5 Acetate buffer 172( mg/mL)

pH 6.8 Phosphate buffer 159( mg/mL)

pH 10.0 Phosphate buffer 123( mg/mL)

Purified Water 123( mg/mL)

Figure 5.4: Solubility Study of Alfuzosin in Different media

0

50

100

150

200

250

pH 2.0

0.01N HCL

pH 4.5

Acetate

buffer

pH 6.8

Phosphate

buffer

pH 10.0

Phosphate

buffer

Purified

Water

mg

/mL

Media

Solubility “mg/mL”

79

5.7.2 Compatibility Studies

5.7.2.1 Differential Scanning Calorimetry

Figure 5.5:DSC of Alfuzosin

Figure 5.6: DSC of Alfuzosin with HPMC K100M

80

Figure 5.7: DSC of Alfuzosin with Guargum 8000 cP

Figure 5.8:DSC of Alfuzosin with Eudragit RLPO

81

Table 5.11: DSC characteristics of pure drug and Combination

with Polymers

Parameters Alfuzosine

HCl (API)

API+HPM

C K100M API+Gaurgum

API+Eudragit

RLPO

On Set (°C) 228.2 226.1 223.0 215.6

Peak (°C) 234.7 232.4 230.1 227.7

Delta H (J/g) -16.53 -7.60 -17.01 -5.59

5.7.2.2 Fourier Transform Infra-Red (FT-IR) spectral analysis

Figure 5.9: IR spectrum of Alfuzosin

82

Figure 5.10: IR spectrum of HPMC K100M

Figure 5.11: IR spectrum of Guargum 8000 cP

83

Figure 5.12: IR spectrum of Eudragit RLPO

Figure 5.13: IR spectrum of Alfuzosin with HPMC K100M

84

Figure 5.14: IR spectrum of Alfuzosin with Guargum 8000 cP

Figure 5.15: IR spectrum of Alfuzosin with Eudragit RLPO

85

Table 5.12: Characteristic peaks of Alfuzosin

Frequency (cm-1) Functional Group

1503,1530,1552 C-C stretching

3183 C-H stretching

1213 C-O stretching

2954 Aromatic ring attached to C-H

stretching

3345 NH2 stretching

1307 C-N

Table 5.13: Characteristic peaks of HPMC K100M


1039 C-C stretching

2923 C-H stretching

1279 C-O stretching

3500 CH2CH(OH) CH3 Stretching value -OH

stretching

Table 5.14:Characteristic peaks of Guargum 8000 cP


870 to1022 C-C stretching

2922 -CH stretching

1154 C-O stretching

3400 OH stretching

Table 5.15: Characteristic peaks of Eudragit RLPO


1262 C-C stretching

2925 C-H stretching

1020 C-O stretching

1734 C=O stretching

86

Table 5.16: Characteristic peaks of Alfuzosin + HPMC K100M


Alfuzosin HCl

1530 C-C stretching

1240 C-O stretching

2924 Aromatic ring attached to C-H stretching

3400 NH2 stretching

1395 C-N stretching

HPMC K100 M

1067 C-C stretching

2920 C-H stretching

1277 C-O stretching

3400 CH2CH(OH) CH3 Stretching value -OH

stretching

Table 5.17: Characteristic peaks of Alfuzosin+Guargum 8000 cP


Alfuzosin HCl

1504,1531 C-C stretching

1241 C-O stretching


3400 NH2 stretching

1395 C-N stretching

Guargum 8000 cps

872 C-C stretching

2924 -CH stretching

1155 C-O stretching

3400 OH stretching

87

Table 5.18: Characteristic peaks of Alfuzosin+ Eudragit RLPO


Alfuzosin HCl

1529 C-C stretching

2925 C-H stretching

1245 C-O stretching


3400 NH2 stretching

1348 C-N stretching

Eudragit RLPO

1277 C-C stretching

2925 C-H stretching

1020 C-O stretching

1731 C=O stretching

5.7.3 Evaluation of Matrix Tablets

5.7.3.1 Evaluation of physical parameters for granules

5.7.3.1.1 Flowability

Table 5.19: Bulk properties of blend

B.No

Parameter

Bulk Density

Tapped Density

Carr’s Index

Hausner’s ratio

Angle of repose (°)

ALF/01 0.339 0.479 29.22 1.412 46.5

ALF/02 0.325 0.482 32.57 1.483 56.7

ALF/03 0.326 0.491 33.60 1.506 56.4

ALF/04 0.345 0.490 29.59 1.420 46.3

ALF/05 0.343 0.457 24.94 1.332 42.1

ALF/06 0.362 0.459 21.13 1.267 41.8

ALF/07 0.342 0.480 28.76 1.403 46.5

ALF/08 0.361 0.500 27.71 1.383 47.1

ALF/09 0.328 0.486 32.51 1.481 56.4

ALF/10 0.399 0.471 15.28 1.180 33.6

ALF/11 0.334 0.464 27.90 1.387 46.3

ALF/12 0.334 0.488 31.55 1.461 56.4

88

5.7.3.2 Evaluation of physical parameters for tablets

5.7.3.2.1 Physical parameters of tablets

Table 5.20: Physical parameters of Tablets

B.No

Parameters

Weight of Tablet (in mg)

Hardness

(in kp)

Thickness

(in mm)

Friability

(%)

ALF/01 297-301 9.1-10.6 5.42-5.50 0.14

ALF/02 299-302 9.4-10.2 5.43-5.51 0.12

ALF/03 298-304 9.0-10.5 5.42-5.49 0.15

ALF/04 299-303 9.1-10.6 5.44-5.50 0.14

ALF/05 300-303 9.5-10.4 5.41-5.49 0.10

ALF/06 301-304 9.8-10.7 5.46-5.54 0.11

ALF/07 349-352 9.7-10.8 5.69-5.75 0.14

ALF/08 347-353 9.9-10.5 5.70-5.74 0.15

ALF/09 349-355 9.6-10.8 5.71-5.73 0.12

ALF/10 355-360 10.7-12.2 5.69-5.74 0.13

ALF/11 348-357 10.8-12.1 5.68-5.74 0.14

ALF/12 347-358 9.8-11.2 5.71-5.76 0.12

89

Figure 5.16: Photograph of prepared ALFUZOSIN extended release Tablets (B.No: ALF/10)

Figure 5.17: Shows the swelling of prepared ALFUZOSIN extended release Tablets at 12 hr (B.No: ALF/10)

90

5.7.3.3 Evaluation of Chemical parameters for Tablets

5.7.3.3.1 Drug Content

Table 5.21: Chemical parameters of tablets

Parameter B.No

ALF/01 ALF/02 ALF/03 ALF/04 ALF/05 ALF/06

Drug

content

( %)

99.2 99.5 99.9 99.8 99.6 99.9

ALF/07 ALF/08 ALF/09 ALF/10 ALF/11 ALF/12

99.7 99.9 99.9 100.1 99.9 99.9

5.7.3.3.2 In-vitro Dissolution Study

Table 5.22: Dissolution values

B.No Cumulative % Drug Release

1hr 2hr 3hr 6hr 12hr 20hr

ALF/01 26.2 92.1 99.8 --- --- ---

ALF/02 53.1 81.7 98.2 --- --- ---

ALF/03 22.3 29.6 63.2 99.2 --- ---

ALF/04 26.2 39.1 46.7 68.5 93.2 99.1

ALF/05 14.5 32.6 50.3 96.2 -- --

ALF/06 12.2 27.7 48.2 82.6 95.4 --

ALF/07 24.5 36.7 45.6 62.5 84.3 95.7

ALF/08 24.9 34.4 48.7 61.7 80.6 95.5

ALF/09 14.2 28.3 31.2 57.6 79.2 94.2

ALF/10 21.2 31.5 41.8 55.9 76.8 91.2

ALF/11 17.6 24.2 39.4 50.5 71.6 89.1

ALF/12 6.5 13.2 26.2 51.3 73.8 92.3

91

Figure5.18: In-vitro drug release of formulations contains Eudragit RLPO

Figure 5.19: In-vitro drug release of formulations

contains Guargum 8000 cP

Figure 5.20: In-vitro drug release of formulations contains HPMC K100M

0 10 20 30 40 50 60 70 80 90

100 110

0 2 4 6 8 10 12 14 16 18 20 22

ALF/01

0 10 20 30 40 50 60 70 80 90

100 110

0 2 4 6 8 10 12 14 16 18 20 22

% D

rug R

elea

se

Time (hr.)

In-vitro drug release of formulations contains Guargum 8000cps

ALF/02

ALF/03

ALF/04

0 10 20 30 40 50 60 70 80 90

100 110

0 2 4 6 8 10 12 14 16 18 20 22

% D

rug R

elea

se

Time (hr.)

In-vitro drug release of formulations contains HPMC K100M

ALF/05

ALF/06

92

Figure 5.21: In-vitro drug release of formulations contains HPMC K100M and Guargum 8000 cP

Figure 22: Photograph shows dissolution of Alfuzosin ER Tablets

Table 5.23: Dissolution profile at different hardness of tablets

(B.No: ALF/10)

Time in

(hr.)

Low Hardness

(8.1-9.3)

Medium Hardness

(10.7 -12.2)

High Hardness

(14.4-15.7)

1 21.1 21.4 18.4

2 30.5 31.8 27.4

6 52.5 55.4 50.5

12 69.6 76.4 70.6

20 82.3 91.5 85.6

0 10 20 30 40 50 60 70 80 90

100 110

0 2 4 6 8 10 12 14 16 18 20 22

% D

rug R

elea

se

Time (hr.)

In-vitro drug release of formulations contains HPMC K100M and

Guargum

ALF/07

ALF/08

ALF/09

ALF/10

ALF/11

ALF/12

93

Figure5.23: Dissolution profile at different Hardness of

Alfuzosin ER tablets

Table 5.24: Comparison of in-vitro release of ALF/10 with

Marketed Product

Time points Marketed Product

(Uroxatral) B.No: ALF/10

1 hour 20.3 21.2

2 hour 28.5 31.5

3 hour 42.9 41.8

6 hour 52.8 55.9

12 hour 80.5 76.8

20 hour 97.4 91.2

F2 value 72.05

F1 value 1.20

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20 22

%D

rug R

elea

se

Time (hr.)

In-vitro drug release of optimised formula at diffrent hardness

Optimum Hardness

(10.7 -12.2)

High Hardness (14.4-

15.7)

Low Hardness (8.1-

9.3)

94

Table 5.25: Alfuzosin f1& f2 values

S.No B.No Dissimilarity

factor ( f1)

Similarity

factor(f2 )

1. ALF/7 8.34 61.42

2. ALF/8 7.26 63.17

3. ALF/9 5.49 61.14

4. ALF/10 1.20 72.05

5. ALF/11 9.31 62.07

Figure5.24: In-vitro drug release of ALF/10 and Marketed Product

0 10 20 30 40 50 60 70 80 90

100 110

0 2 4 6 8 10 12 14 16 18 20 22

%D

rug R

elea

se

Time (hr.)

In-vitro drug release of ALF/10 and Marketed Product

ALF/10

Reference

95

5.7.4 Kinetic modeling system for In-vitro release

Table 5.26: In vitro release kinetics of Alfuzosin ER tablets

Correlation Coefficient (r2)

k (/h)

n value B.No: Zero First Higuchi Erosion Peppas

Uroxatral 0.9711 0.9832 0.9944 0.9975 0.9925 0.1740 1.866

ALF/01 0.9097 0.9902 0.9385 0.9920 0.9492 2.9559 0.703

ALF/02 0.9882 0.9715 0.9970 0.9942 0.9970 1.6304 1.755

ALF/03 0.9780 0.9681 0.9772 0.9858 0.9671 0.3737 1.058

ALF/04 0.9320 0.9976 0.9786 0.9923 0.9904 0.1627 2.137

ALF/05 0.9991 0.9728 0.9962 0.9883 0.9983 0.2713 0.943

ALF/06 0.9164 0.9941 0.9646 0.9762 0.9643 0.2639 1.100

ALF/07 0.9512 0.9992 0.9896 0.9955 0.9938 0.1487 2.161

ALF/08 0.9535 0.9939 0.9893 0.9956 0.9903 0.1427 2.183

ALF/09 0.9562 0.9982 0.9900 0.9957 0.9864 0.1396 1.550

ALF/10 0.9625 0.9992 0.9943 0.9956 0.9948 0.1129 2.035

ALF/11 0.9674 0.9968 0.9937 0.9954 0.9888 0.1037 1.786

ALF/12 0.9605 0.9976 0.9918 0.9961 0.9797 0.1300 1.064

96

Selected formulation Kinetic models plots (B.NO: ALF/10)

Figure 5.25: Zero order plot for B. No: ALF/10

0

20

40

60

80

100

120

0 5 10 15 20 25

Co

mu

lati

ve p

erce

nt

dru

g re

leas

e (

%)

Time (hr)

Uroxatral

ALF/10

Linear (Uroxatral)

Linear (ALF/10)

97

Fig 5.26: First order plot for B.No: ALF/10

0

0.5

1

1.5

2

2.5

0 5 10 15 20 25

Log

per

cen

t re

mai

nin

g to

be

rele

ase

d

Time (hr)

Uroxatral

ALF/10

Linear (Uroxatral)

Linear (ALF/10)

98

Fig 5.27: Higuchi plot for B.No: ALF/10

0

20

40

60

80

100

120

0.000 1.000 2.000 3.000 4.000 5.000

Co

mu

lati

ve p

erce

nt

dru

g re

leas

e (

%)

Square root time (hr)

Uroxatral

ALF/10

Linear (Uroxatral)

Linear (ALF/10)

99

Fig 5.28: Erosion plot for B.No: ALF/10

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800

0.900

1.000

0 5 10 15 20 25

(1-Q

)1/3

Time (hr)

Uroxatral

ALF/10

Linear (Uroxatral)

Linear (ALF/10)

100

Fig 5.29: Korsmeyer-Peppas plot for B.No: ALF/10

0.000

0.500

1.000

1.500

2.000

2.500

0 0.2 0.4 0.6 0.8 1 1.2 1.4

log

frac

tio

n r

ele

ase

Log Time (hr)

Uroxatral

ALF/10

101

5.7.5 Stability Studies:

Stability studies for FormulationB.N0:ALF/10 revealed that

there was no significant change in appearance, assay, and drug

release profile at 40°C± 2° & 75% RH till 3 months.

Table 5.27: Stability study parameters

Parameters Time period

Initial 1 Month 2 Month 3 Month

Description Complies Complies Complies Complies

Drug content

(%)

100.1 99.9 99.8 99.9

Uniformity of dosage units ( %)

Tablet -1 98.2 99.2 99.6 98.7

Tablet -2 99.5 98.1 98.7 99.4

Tablet -3 99.7 99.6 100.2 99.7

Tablet -4 99.0 100.1 99.5 100.7

Tablet -5 101.2 99.7 99.8 99.6

Cumulative % Drug Release

1Hr 21.2 20.5 20.8 21.1

2Hr 31.5 30.7 30.9 31.3

3Hr 41.8 41.1 41.5 42.2

6Hr 55.9 56.1 55.5 56.3

12Hr 76.8 76.9 77.1 77.3

20Hr 91.2 90.9 91.5 92.5

102

5.8 DISCUSSION

5.8.1 The solubility results are shown in Table 5.10. Alfuzosin

Hydrochloride was soluble in pH 2.0-0.01N HCl, pH4.5 Acetate buffer,

pH6.8 Phosphate buffer, pH10 Phosphate buffer and purified water.

Comparatively all the media alfuzosin was more soluble in 0.01NHcl.

5.8.2 Differential Scanning Calorimetry (DSC) results are shown in

Table 5.11. The DSC thermograph for Alfuzosine showed melting

peak starts at 228.2°C ending at 234.7°C and the mixer of the

Alfuzosin + HPMC K100M, Alfuzosin + Guar gum & Alfuzosin +

Eudragit RLPO showed melting points starting at 226.1°C, 223.0°C &

215.6°C ending at 232.4°C, 230.1°C & 227.7°C respectively. The

endothermic energy of Alfuzosine was -16.53 J/g and the mixer of the

Alfuzosin + HPMC K100M, Alfuzosin + Guar gum & Alfuzosin +

Eudragit RLPO were -7.60J/g, -17.01J/g& -5.59 J/g respectively.

From the obtained results concluded that there is no interaction

between the selected polymers and drug substance.

5.8.3 Fourier Transform Infra-Red (FT-IR) spectral results are shown

in Table 5.12 – 5.18. The FT-IR spectra of pure drug showed

characteristic peaks at 1503 cm-1, 1530 cm-1, 1552 cm-1,3183 cm-1,

1213 cm-1,2954 cm-1, 3345 cm-1& 1307 cm-1. The mixer of drug

substance and polymers of the selected in the formulations also

showed same characteristic peaks with linear and shift so these

values supported that there is no interaction between the selected

polymer and the drug substance.

103

5.8.4 The results of bulk properties are shown in Table 5.19.

The bulk density of the prepared formulations are in the range of

0.325g/mL to 0.399g/mL.

The tapped density was found to be in the range of 0.457g/mL to

0.500g/mL.

The Carr’s index and Hausner’s ratio varies in the range of 15.28 %,

1.180 to 33.60 %, 1.506 respectively.

Angle of repose was found to be in the range of 33.6° to 56.7°. The

bulk properties of B.No: ALF/10 was showed flow properties (15.28

%,1.18, 33.6°)respectively.

So the results clearly indicate that the preferred blend have good

flowability and compressibility.

5.8.5 Results of tablet weight variation are shown in Table 5.20.

All batches were found within specified range ±5.0% as per

Indian Pharmacopeia.

5.8.6 Tablet Thickness results are shown in Table5.20.

Thickness of tablet containing total weight 300 mg was found

in the range of 5.41 to 5.54 mm. Thickness of tablet containing total

weight 350 mg was found in the range of 5.68 to 5.76 mm

5.8.7 Hardness results are shown in Table 5.20.

Hardness of all tablets were found in the range of 9.0 to 12.2 kp.

Selected batch (B.No: ALF/10) found with 10.7 to 12.2kp.

104

5.8.8 Friability results are shown in Table 5.20.

Friability of all tablets was found in the range of 0.10 - 0.15% w/w,

which found within the specified limit. Friability of selected batch

(B.No: ALF/10) was found to be 0.13%.

5.8.9 The results of the assay shown in Table5.21.

The assay results are found within the pharmacopeial limits which

indicate uniformity in drug content for all the prepared formulations.

5.8.10 The results of Dissolution studies are shown in Table5.22.

The formulation prepared with Eudragit RLPO (40 % w/w

concentration) alone (B.No: ALF/01) able to control drug release

99.8% at 3 hours.

Those formulations containing guar gum alone (B.No: ALF/02,

ALF/03, ALF/04) contain in the concentration of 13.33, 26.67& 60.00

% w/w respectively are able to control drug release 98.2% at 3 hours,

99.2% at 6 hours and 99.1% at 20 hours respectively.

The formulations contain HPMC K100M alone (B.No: ALF/05,

ALF/06) in the 33.33%, 50.0% concentrations released the drug in

96.2% at 6 hours, 95.4% at 12 hours respectively.

The formulation containing the combination of HPMC K 100M

and Guar gum 8000 cp (B.No: ALF/07, ALF/08, ALF/09, ALF/10,

ALF/11 & ALF/12) at the concentrations of 28.57 & 8.57, 30 & 10,

28.57 & 11.49, 31.429 & 11.429, 32.857 & 12.857, 42.857 & 22.857

respectively controls drug release 95.7% at 20 hours, 95.5% at 20

hours, 94.2% at 20 hours, 91.2% at 20 hours, 89.1% at 20 hours and

92.3% at 20 hours respectively.

105

Among all the formulations B.No: ALF/10 are shown able to

drug release over 24 hours.

Marketed formulation also evaluated for the comparison of the

drug release which shows 97.4% released in 20 hours and found that

the B.No: ALF/10 is shows similar release of the drug as that of the

marketed formulation.

5.8.11 The similarity and dissimilarity factor values are shown in

Table5.25.

The f1, f2 are calculated by using the equation proposed by More

et al, the results of formulation (B.No: ALF/10) f1= 1.20, f2= 72.05 so,

it indicates the proposed formulation is similar to that of the marketed

formulation.

5.8.12 The results of kinetic profile are shown in Table5.26.

The release profile was studied for kinetics of the drug release

by zero order and first order kinetics. The correlation coefficient value

(r2) of zero order and first order for all formulation were found to be in

the range of 0.9097-0.9991 and 0.9681-0.9992. These results indicate

that the release follows first order kinetics.

The mechanism of drug release was studied by using Higuchi’s,

Erosion and Peppas model. The correlation r2 values found to be

(0.9385 – 0.9970),(0.9762 – 0.9975) and (0.9492 – 0.9983)

respectively, this results indicates the release mechanism follows with

super case II transport.(As the n value more than1) From the observed

results indicate the drug release follows first order kinetics with

diffusion mechanism.

106

5.8.13 The results of stability studies are shown in Table No: 5.27.

The stability studies were conducted on the selected formulation

(B.No: ALF/10) at 40°C/75% RH for 3 months. The tablets were

evaluated for Description, Assay, uniformity of dosage units and

Dissolution.

There is no significance difference between the initial and final

exposed samples with required physical stability and chemical

stability like assay and dissolution. So this indicates the formulation

is stable.

chapter - 5 development and evaluation of alfuzosin...

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