FORMULATION AND EVALUATION OF FLOATING MATRIX TABLETS OF METFORMIN HCl FOR THE TREATMENT OF TYPE-2 DIABETES MELLITUS

Floating matrix tablets of Metformin hydrochloride were developed and evaluated to increase bioavailability by increasing gastric residence time and sustained release of drug in the upper part of gastrointestinal tract thereby diminishing side effects and enhanced patient compliance. The tablets were formulated by using central composite design having two independent variables at three levels. Independent variables were total amount of hydrophilic gel forming polymers (Hydroxyl Propyl Methyl Cellulose K15M and Carbopol 934P) X1 and polymer-polymer ratio X2. The prepared formulations were evaluated for various physicochemical, buoyant and in-vitro drug release characteristics. All formulations possessed good floating properties with total floating time more than 12 hours. Statistical Optimization carried out for various responses like ‘n’ of Peppas equation, ‘K’ of zero order and ‘n’ of higuchi equation and T80%. Optimized formulation was found to float for longer duration and provided more sustained release of the drug. Release kinetics of optimized formulation followed Higuchi model with anomalous non -fickian diffusion. Hence Optimized floating matrix tablet could be a promising delivery system for Metformin hydrochloride with sustained release action and improved drug availability. INTRODUCTION: Diabetes mellitus is a metabolic disease characterized by high blood glucose level resulting from defects in insulin secretion, insulin action or both 1 . It is a chronic disorder that affects the metabolism of carbohydrates, fats, proteins and electrolytes in the body, leading to severe complications which are classified into acute, sub-acute and chronic 2 .