Formulation, evaluation and optimization of sustained release tablets of indapamide using hydrophilic matrix system

Different formulations of Indapamide 1.5mg sustained release tablets were formulated using wet granulation method using hydrophilic polymer. The tablets were subjected to physicochemical studies, in vitro release studies, kinetic modeling and stability studies to find out the best formulation. The in vitro release studies were conducted for 16 hours using USP 30 apparatus type I (Basket method) at pH 6.8 Phosphate buffer. The release mechanisms were then treated with zero order, higuchi, first order and Korsemeyer-Peppas equations. In vitro release patterns and kinetic results of different models were compared with the innovator brand. All formulations along with innovator brand followed zero order release pattern. According to Korsmeyer-Peppas equation release mechanisms of all formulations were super case II transport. All the kinetic treatments and comparison with innovator brand showed that F-5 was the most successful formulation. The optimized formulation was subjected to stability studies and no significant changes were found in physicochemical properties and release pattern. The result of the study indicated the effect of hydrophilic polymers on the release of Indapamide drug from the sustained release matrix tablet.