Development and Evaluation of Sustained Release Matrix Tablets of Indapamide using Methocel K15M CR

In the present study an attempt has been taken to develop Indapamide sustained release matrix tablet using Methocel K15M CR by direct compression method. Various amount of polymer was used in the five proposed formulations (F-1to F-5) for the study of release rate retardant effect at 26.47%, 29.41%, 32.35%, 35.29% and 38.24% of total weight of tablet matrix respectively. Then the tablets were evaluated in terms of their physical parameters (weight variation, hardness, friability and thickness), drug content and in vitro release studies. All the formulations showed compliance with pharmacopoeial standards. The in vitro dissolution study were conducted using USP 30 dissolution apparatus type I (Basket method) in 900 ml phosphate buffer (pH 6.8) at 100 rpm for a total period of 24 hours. The release mechanisms were explored and explained by Zero order, Higuchi, First order and Korsmeyer-Peppas equations. Based on the dissolution data comparison with innovator brand formulation F-3 (32.35% Methocel K15M CR w/w) was found as the best formulation. The drug release profile of this formulation was well controlled and uniform throughout the dissolution studies. The drug release of formulation F-3 followed First Order kinetic model (r2 = 0.99) and the mechanism was found to be non-Fickian/anomalous according to Korsmeyer-Peppas equation.