FORMULATION AND DEVELOPMENT OF ANTI-DIABETIC OSMATIC TABLETS

Extended release formulation of glipizide based on osmotic technology was developed and evaluated. The developed formulation equalent to US marketed innovators product glucotrol XL regarding in vitro drug release. Bilayer osmotic push pull tablets of glipizide were developed using different polymers (Polyox WSR-N80, HPMC E-50 and Polyox WSR Coagulant) and different osmogens (sodium chloride and Potassium chloride). Tablets were coated with a semipermiable membrane using 5% w/v cellulose acetate (CA) in acetone and water, PEG 400 (9:1 ratio of CA) as plasticizer. The effect of different formulation variables namely effect of polymer, osmogen, coating thickness, agitational intensity, pH of the media and plasticizer effect was studied. Drug release rate was increased as the decrease of Polyox WSRN ? 80 (or) HPMC E -50 amount in Drug layer. Drug release rate was increased significantly as the increases of Sodium chloride (or) Potassium chloride amount in Push layer. The drug release rate was directly proportional to the amount of plasticizer and indirectly proportional to coating thickness. Drug release rate was independent of agitational intensity. All polymers and excipients used in the optimized formula were found to be compatible with drug and it was confirmed by FT-IR studies. The developed formulation was extended up to 16hrs. The developed formulation was extended up to 16hrs. F4 (n= 1.836),endured super case II release, during the dissolution study, which indicated that polymer relaxation had a significant role in the drug release mechanism.