International Journal of PharmTech Research CODEN (USA): IJPRIF ISSN : 0974-4304

Vol.6, No.2, pp 607-622, April-June 2014

Formulation and In-Vitro Evaluation of Bilayer Tablets

containing Pioglitazone HCl and Gliclazide for Type II Diabetes

Sanjay K. Sharma1*, Shailender Mohan1, Manish Jaimini1, Bhupendra Singh Chauhan1, Arindam Chatterjee1

1Dept. of Pharmaceutics, Jaipur College of Pharmacy, ISI- 15, RIICO, Sitapura Institutional Area, Sitapura, Jaipur, Rajasthan-302022, India.

*Corres.Author: sanjaysharma.pharma@gmail.com Phone No.: +919829206078.

Abstract: An attempt was made to formulate the bilayer dosages forms containing Pioglitazone HCl as immediate release layer and Gliclazide as modified release layer, for the management of Type II Diabetes Mellitus. The individual layers were prepared for the estimation of the effect of polymers (HPMC, EC, MCC) and super-disintegrant (KYRON T-314) used and they were optimized individually. Finally, selected individual formulations were subjected to the formulation and compression as Bilayer Tablets. The prepared tablets were characterized using various tablet parameters and the data was brought forth. The final preparations showed the maximum release of about 97 % for the immediate release layer and 91.73 % release of the modified release layer. Keywords: Bilayer Tablets, Diabetes Mellitus, Pioglitazone HCl, Gliclazide, Immediate Release, Modified Release, HPMC, KYRON T-314, Release Kinetic Models.

INTRODUCTION:

Pharmaceutical tablets are the dominant dosage form for drug delivery, occupying approximately two-thirds of the global market. Generally, they are produced by compressing dry powder blends consisting of a number of components with different functionalities in a die.

In the recent years, pharmaceutical drug product manufacturers have oriented their product development activities to fixed dose combinations (FDCs) for treatments like type 2 diabetes, hypertension, pain and HIV/AIDS to advert a few. Several different approaches are been employed to deliver the FDC products to the patients such as multilayer tablets 1, bilayer floating tablet2,3, compression coating, active coating4,5 and buccal/mucoadhesive delivery systems6,7. The controlled drug delivery systems typically require more exacting mechanical testing, characterization, and monitoring techniques with faster response times than those possibly available with traditional measurement approaches8-10. It is technically difficult to ensure that a tablet possesses both a certain mechanical strength and a low packing density, so that it is sufficiently strong to maintain its

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integrity during handling and transport and also weak enough to satisfy the dispersion and dissolution requirements.

Diabetes mellitus is a group of metabolic diseases in which a person has high blood sugar, either because the pancreas does not produce enough insulin, or because cells do not respond to the insulin that is produced11. The term diabetes mellitus describes a metabolic disorder of multiple etiologies characterized by chronic hyperglycemias with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both. Diabetes mellitus may present with characteristic symptoms such as thirst, polyuria, blurring of vision, and weight loss. In its most severe forms, ketoacidosis or a non–ketotic hyperosmolar state may develop and lead to stupor, coma and, in absence of effective treatment, death. Diabetes is a chronic illness that requires continuing medical care and ongoing patient self-management education and support to prevent acute complications and to reduce the risk of long-term complications12. Non‐insulin dependent (Type II) diabetes mellitus is a heterogeneous disorder characterized by an underlying insufficiency of insulin. This insufficiency results from defective insulin utilization and can be corrected by administration of one or more of the currently available oral hypoglycemic agents.

Pioglitazone is a potent and selective agonist for peroxisome proliferator-activated receptor-gamma (PPARgamma) and it has a mechanism of action that is dependent on the presence of insulin for activity.. Activation of nuclear PPARgamma receptors influences the production of a number of gene products involved in glucose and lipid metabolism. PPARgamma is abundant in the cells within the renal collecting tubules; fluid retention results from stimulation by thiazolidinediones which increases sodium reabsorption12.

Gliclazide stimulates insulin secretion from functional pancreatic β-cells and increases the sensitivity of the β-cells to a glucose stimulus (some residual β-cell function is therefore necessary). Gliclazide restores the diminished first-phase of insulin secretion noted in non-insulin dependant diabetes mellitus.

MATERIAL AND METHOD:

Pioglitazone HCl was provided by Torrent Pharmaceutical, Ahemdabad, India. Gliclazide was generously provided by Dr. Reddy’s Laboratories, Hyderabad. PVP K30, HPMC K15M, HPMC K100M, Ethyl Cellulose were gifted by Colorcon Labs, sodium bi-carbonate, mag. sterate, talc, lactose was purchased from CDH Pvt. Ltd, New Delhi. KYRON T-314 was gifted by Corel Pharma Chem Ltd. All the ingredients used were of analytical grade.

Manufacturing of Bilayer tablets:

FTIR Spectroscopy: The active pharmaceutical ingredient was identified by FTIR analysis of the sample obtained from sources. The sampling technique was mixing the API with the KBr and forming of the pellet which was then analyzed in 400-4000 wave number range by the FTIR Spectrophotometer.

Figure 1: FTIR of Pure Pioglitazone HCl

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Figure 2: FTIR of Pure Gliclazide

Drug Excipient Interaction Study:

Figure 3: FTIR of Pioglitazone HCl and KYRON T-314

Figure 4: FTIR of Pure Pioglitazone HCl and HPMC K15M

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Figure 5: FTIR of Pure Pioglitazone HCl and HPMC K4M

Figure 6: FTIR of Pure Pioglitazone HCl and HPMC K100M

Figure 7: FTIR of Pure Pioglitazone HCl and EC

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Figure 8: FTIR of Pure Pioglitazone HCl and PVP K30

Interaction Study of Gliclazide: Interaction Study of Gliclazide and polymers blend (EC, HPMC K15cps, HPMC K100M) was done. No significant interaction was found owing to the IR range of the drug.

Figure 9: FTIR of Pure Gliclazide and HPMC K4M

Figure 10: FTIR of Pure Gliclazide and HPMC K100M

Figure 11: FTIR of Pure Gliclazide and HPMC K15M

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Figure 12: FTIR of Pure Gliclazide and EC

Figure 13: FTIR of Pioglitazone HCL and Gliclazide (Blend)

Compatibility of the drug with excipients and drug-drug interaction was determined by FTIR spectral analysis. This study was carried out to detect any changes on chemical constitution of the drug after it is combined with the excipients. The scanned graphs and the results of interaction study were pictured in the Figure 1-13. The I.R. spectra of mixture of drug and polymer indicated that there is no interaction between drug and polymers, hence polymers and drug were chosen for further investigations.

Preparation of Individual Release Layers:

Immediate Release Layer:

The immediate layer was prepared by mixing the ingredients in the proper proportion. The following steps were followed during the preparation of the direct compression layer:

Step 1. Sift of API (Pioglitazone HCl) and Excipients: All ingredients were weighed accurately and sieved.

Step 2. Dry mix: Pioglitazone, microcrystalline cellulose, KYRON T-314 and lactose were mixed together.

Step 3. The mixing was done till the through mixing was confirmed.

Step 4. Sifting of Lubricants: The lubricant (Mag Sterate) was shifted and transferred to the mixture to aid the flow property.

Step 5. Compression: the mixture was compressed into the tablet using the low force compression cycle.

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Extended Release Layer:

The extended release layer was prepared by mixing the ingredients in the proper proportion and then subjected to wet granulation. The following steps were followed during the preparation of the wet granulation layer:

Step 1. Dry mix: Gliclazide, HPMC K100M/HPMC K15M/EC were mixed in proper proportion according to the formula developed.

Step 2. Granulation and drying of granules: the binder solution was added in dry mixed material in the mortar and the wet compact mass was passed through sieve and sifted wet granules were collected and kept for drying at a temperature of 1000C for the reported period of time. The granules were dried in tray drier and sufficient drying was conferred by taking the LOD calculation into consideration, of the dried granules.

Step 3. Lubrication: after the drying of the granule, suitable lubricant was added to the granule so as to aid the flow property.

Step 4. Compression: the granules were subjected to the compression using the suitable compression force.

Preliminary Trial batches of Immediate Release Layer of Pioglitazone HCl:

Formulations: 6 batches of immediate release layer of Pioglitazone HCl were formulated and 10 batches of modified release layer of Gliclazide were formulated having following compositions.

Table 1: Composition of IR Layer of Pioglitazone HCl Ingredients/ Formulation Code FP1 FP2 FP3 FP4 FP5 FP6 Pioglitazone 15 15 15 15 15 15 MCC (%) 10 15 20 10 15 20 KYRON T-314 (%) 1 1 1 3 3 3 Sodium Bi-carbonate (%) 10 10 10 10 10 10 Mag. Sterate (%) 1 1 1 1 1 1 Talc (%) 1 1 1 1 1 1 Lactose (%) Q.S. Q.S. Q.S. Q.S. Q.S. Q.S. Total Weight 150 150 150 150 150 150

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Preliminary Trial batches of Modified Release Layer of Gliclazide:

Table 2: Composition of MR Layer of Gliclazide

Formulation Code Ingredients

FG1 FG2 FG3 FG4 FG5 FG6 FG7 FG8 FG9 FG10

Gliclazide 120 120 120 120 120 120 120 120 120 120

HPMC K15M 2 4 2 4 2 4 2 4 2 4

HPMC K100M 10 20 - - 10 20 20 10 10 20

EC - - 10 20 10 20 20 10 20 10

Sodium Bi Carb. 5 5 5 5 5 5 5 5 5 5

Mag. Sterate 1 1 1 1 1 1 1 1 1 1

Talc 1 1 1 1 1 1 1 1 1 1

Lactose Q.S. Q.S. Q.S. Q.S. Q.S. Q.S. Q.S. Q.S. Q.S. Q.S.

Total Weight 500 500 500 500 500 500 500 500 500 500

Preparation of the bilayer tablets using the optimized formulation:

Form the in-vitro dissolution profile of the individual formulations following three formulations from each formulation were selected and developed into the bilayer tablets using the following steps:

Step1: Initially, Pioglitazone HCl containing layer was compressed using the low compression force to aid the adhesion of the second layer to be compressed. The tablets were ejected and preserved for further compression with the second layer.

Step2: The granules of the second layer containing Gliclazide were transferred into the die and the initially compressed tablet of initial layer was placed over it. Final compression was done employing the suitable compression force and the tablets were preserved for the further analyzing viz. weight variation, friability, and hardness and in-vitro dissolution performance.

Table 3: Composition of Bilayer Tablets:

Formulation Code Ingredients

CF1 (FP1:FG1)

CF2 (FP3:FG3)

CF3 (FP5:FG5)

Pioglitazone HCl 15 15 15 Gliclazide 120 120 120 MCC 15 30 22.5 HPMC K15M 10 10 10 HPMC K100M 50 --- 50 EC --- 50 50 KYRON T-314 1.5 1.5 4 Sodium Bi-carbonate 40 40 40 Mag. Sterate 6.5 6.5 6.5 Talc 6.5 6.5 6.5 Lactose 385.5 370.5 325.5 Bilayer Tablet Weight 650 650 650

Evaluation of the bilayer tablets:

The prepared bilayer tablets from each optimized formulation batches were tested against the official standard evaluation parameters to ensure the proper manufacturing and release rate of the dosages of the drug. Following evaluation parameters were performed:

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Size, shape and thickness:

The size and shape of the tablets can be dimensionally described, monitored and controlled. The thickness of the tablets is the only dimensional variable related to the process of tabletting. At a constant compressive load, tablet thickness varies with the change in the die fill, with particle size distribution and packing of the particle mix being compressed, and with the tablets weight, while with the constant die fill, thickness varies with the variations in compressive load. The tablet thickness should be maintained well within a ± 5% variation of the standard value13.

Weight variation:

Weigh individually 20 tablets selected at random and calculate the average weight. Not more than two of the individual weights deviate from the average weight by more than the percentage shown in the table13, 14 and none deviates by more than twice that percentage15.

Table 4: Weight Variation standards:

Average wt of the tablets (mg) Maximum %age difference allowed

130 or less 10 130-324 7.5 More than 324 5

Friability:

This test is applicable to compressed tablets and is intended to determine the physical strength of tablets and is measured by Roche Friabilator. For tablets with an average weight of 0.65 g or less take a sample of whole tablets corresponding to about 6.5 g and for tablets with an average weight of more than 0.65 g take a sample of 10 whole tablets. The tablets were de-dust carefully and weighed accurately. The tablets were place in the drum and the drum was rotated 100 times. The tablets were removed after 100 revolutions, any loose dust was removed from them and weighed accurately again. The test is run only once unless the results are difficult to interpret or if the weight loss is greater than the targeted value, in which case, the test is repeated twice and the mean of the three tests is determined. A maximum loss of weight (from a single test or from the mean of the three tests) not greater than 1.0 per cent is acceptable for most tablets. If obviously cracked, chipped or broken tablets are present in the sample after tumbling, the sample fails the test15.

Hardness:

Hardness is the measure of the strength of the tablet to withstand the mechanical shock of manufacturing, packaging and transportation. Hardness is sometimes also referred to as tablet crushing strength. The hardness of the tablets is estimated by Pfizer hardness tester or Erweka tester13.

Drug content:

10 tablets are taken randomly and weighed. The average weight is calculated and the tablets are then crushed in the mortar. The weight equivalent to the label claim is weighted accurately and is dissolved in 100 ml of the solvent being used for the dissolution study. The solution thus prepared is analyzed spectro-photometrically and the concentration is determined.

In-vitro dissolution study:

In vitro dissolution studies of bilayer tablets were studied using USP XXIII tablet dissolution test apparatus-I employing a paddle stirrer. 900 ml of 0.1N HCl (pH 1.2) was used as a dissolution medium for first two hours and then was replaced with Phosphate Buffer solution (pH 7.4) for specified time. The temperature of the dissolution medium is maintained to 37 ± 0.5ºC. One tablet from each batch was used in each test. 5 ml of the sample of dissolution medium was withdrawn by means of pipette at known intervals of time and the sample was filtered using the whattman filter paper. The volume withdrawn at each interval was replaced with same

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quantity of fresh dissolution medium. The sample is analyzed, for drug release and release kinetics, spectrophotometericaly using UV-visible spectrophotometer (Shimadzu -1800) after suitable dilutions.

RESULT AND DISCUSSION:

Table 5: Physical properties of formulations CF1 to CF3: Formulation

code Hardness (kg/cm2)

Friability (%)

Thickness (mm) Weight Variation (mg)

CF1 6.5 0.61 3.16 ± 0.16 652 ± 0.31% CF2 5.5 0.65 3.40 ± 0.09 656 ± 0.21% CF3 6.5 0.63 3.21 ± 0.21 655 ± 0.30%

Table 6: Drug content of formulations CF1 to CF3:

Percent drug content ± SD Formulation code Pioglitazone HCl Gliclazide CF1 98.69 ± 0.014 95.43 ± 0.063 CF2 97.07 ± 0.024 96.57 ± 0.039 CF3 98.38 ± 0.014 94.94 ± 0.036

In-vitro dissolution study:

Initially all the formulations of the Bilayer tablets were subjected to in-vitro dissolution study and the data was generated and various release kinetic models were implicated. The three formulations have been found to have maximum release.

Table 7: In-vitro dissolution data for bilayer tablets:

% Cumulative Drug Release Formulation Code

Pioglitazone HCl Gliclazide CF1 94.925 ± 0.021 90.991 ± 0.11 CF2 96.931 ± 0.04 90.730 ± 0.17 CF3 97.719 ± 0.014 91.739 ± 0.031

Release Graphs for the Formulations CF1-CF3:

Figure 14: Zero Order Release Plot of Formulation CF1

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Figure 15: First Order Release Plot of Formulation CF1

Figure 16: Higuchi Release Plot of Formulation CF1

Figure 17: Korsmeyer-Peppas Release Plot of Formulation CF1

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Figure 18: Zero Order Release Plot of Formulation CF2

Figure 19: First Order Release Plot of Formulation CF2

Figure 20: Higuchi Release Plot of Formulation CF2

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Figure 21: Korsmeyer-Peppas Release Plot of Formulation CF2

Figure 22: Zero Order Release Plot of Formulation CF3

Figure 23: First Order Release Plot of Formulation CF3

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Figure 24: Higuchi Release Plot of Formulation CF3

Figure 25: Korsmeyer-Peppas Release Plot of Formulation CF3

Kinetic Models (correlation coefficient R2):

Table 8: Drug Kinetic of Bilayer Formulation: Pioglitazone HCl (immediate release)

Zero order First order Higuchi model

Korsmeyer-peppas

Formulation Code

R2 R2 R2 R2

Best Fit Model

CF1 0.974 0.950 0.949 0.982 Korsmeyer-peppas

CF2 0.983 0.908 0.961 0.961 Zero order CF3 0.975 0.922 0.953 0.974 Zero order

Table 9: Drug Kinetic of Bilayer Formulation: Gliclazide (modified release):

Zero order First order Higuchi model

Korsmeyer-peppas

Formulation Code

R2 R2 R2 R2

Best Fit Model

CF1 0.788 0.969 0.931 0.921 First order CF2 0.805 0.973 0.939 0.914 First order CF3 0.853 0.983 0.960 0.912 First order

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CONCLUSION:

The attempt was made to develop bilayer tablets containing Pioglitazone HCl as immediate release and Gliclazide as modified release for the management of Type II Diabetes. All the developed bilayer tablets were evaluated for weight variation, friability, thickness and hardness and the results are given in table. The percent deviation from the average weight was found to be within the prescribed official limits. Hardness of bilayer tablets was found to be in the range of 5.5 to 6.5 Kg/cm2 and the friability of all the developed bilayer tablets was found to be in the range of 0.61 to 0.65 %, fulfilling the official requirements (not more than 1%). Thickness of bilayer tablets was found to be in the range of 3.16 to 3.40 mm.

Drug content estimation data for all the optimized batches are given in table. It was found to be in the range of 97.07 to 98.69% for Pioglitazone HCl and 94.94 to 96.57% for Gliclazide with low values of standard deviation indicates uniform drug content in the bilayer tablets developed.

The study concluded that the bilayer formulation CF3 shows higher dissolution rate compared with other formulations. Release profile of Pioglitazone HCl from formulations indicate that lower MCC (Formulations CF1 and CF3) and lactose (Formulation CF3) content displayed higher release rates as compared to formulation with higher MCC and lactose content (Formulation CF2). Also the concentration of KYRON T-314 is also found to influence the release rate of the drug. It was found that formulation containing the highest concentration of superdisintegrants (Formulation CF3) has grater release then other subsequent formulations (Formulations CF1 and CF3). In short, it can be concluded that formulation CF3 has the maximum release rate, releasing 97.72 % of drug in 60 mins. Similarly, the release profile of Gliclazide from formulations indicate that lower HPMC K15M (Formulation CF3) and lactose (Formulation CF3) content displayed higher release rates as compared to formulation with individual HPMC K15M, HPMC K100M, EC (Formulations CF1 and CF2) and higher lactose content (Formulations CF1 and CF2). In short, it can be concluded that formulation CF3 has the maximum release rate, releasing 91.74 % of drug in 720 mins (Figures 14-25). The kinetics data of CF3 formulation shown good fit in Zero Order Kinetic Release Model which indicated the best linearity. The release kinetic data for all the Gliclazide formulations is shown in table. The kinetic data of CF3 formulation showed good fit in First Order Kinetic Release Model.

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