Abstract The drug chosen for the present investigation, Metformin hydrochloride, is an orally active antidiabetic agent. It is effectively used in the treatment of non-insulin dependent diabetes mellitus (NIDDM) Type II. It is more appropriately referred to as antihyperglycemic agent and found to be well-tolerated and safe even on chronic use. The objective of this study was to design and evaluate oral sustained drug delivery system for metformin hydrochloride using hydrophilic polymers such as HPMC K4M and HPMC K100M. Four batches were prepared by using HPMC K4M in drug: polymer ratio of 5:1, 6:1, 7:1, 8:1 and four batches using HPMC K100M in ratios of 5:1, 6:1, 7:1, 8:1. Further formulations were modified by varying the ratios of diluents i.e. F9, F10, F11, F12 to check the effect of diluents on drug release. Matrix tablets were prepared by wet granulation method and were evaluated for weight variation, drug content, friability, hardness, thickness, and in-vitro dissolution. Among the formulations studied, formulation F6 containing HPMC K100M (6:1) showed sustained release of drug for 24 hrs with cumulative percent drug release of 98.11%, similar to that of the research listed drug. The kinetic treatment showed that the optimized formulation follow first-order kinetic with release exponent (n) 0.711 and having good stability as per ICH guidelines. The matrix formulation F6 showed sustained release of metformin hydrochloride by the diffusion mechanism.
Keywords Metformin hydrochloride, Sustained drug delivery system, Hydrophilic polymers, HPMC K4M, HPMC K100M.