Abstract The objective of this study was to design and evaluate oral sustained drug delivery system for metoprolol succinate using hydrophilic polymers such as HPMC K4M and HPMC K100M batches. Four batches were prepared by using HPMC K4M in drug: polymer ratio of 1:1, 1:1.5, 1:2, 1:3 and five batches using HPMC K100M in ratios of 1:1, 1:1.25, 1:1.5, 1:1.75, 1:2. Further formulation F9 was modified by varying the ratios of diluents i.e. F10, F11, F12, F13 to check the effect of diluents on drug release. Matrix tablets were prepared by wet granulation method and were evaluated for weight variation, content uniformity, friability, hardness, thickness and in vitro dissolution. Among the formulations studied, formulation F9 containing HPMC K100M (1:2) showed sustained release of drug for 20 h with cumulative percent release of 88% similar to that of the research listed drug. The kinetic treatment showed that the optimized formulation follow first order kinetic with release exponent (n) 0.579 and having good stability as per ICH guidelines. No chemical interaction between drug and gums was seen as confirmed by DSC studies. The matrix formulation F9 showed sustained release of metoprolol succinate by the diffusion mechanism.
Keywords Sustained release, Hydrophilic gums, HPMC K4M, HPMC K100M, Metoprolol succinate.