Abstract: Aim In this study, compound metformin/glipizide bilayer extended release tablets were formulated with hydroxypropyl methylcellulose (HPMC) by wet granulation technique in order to tackle the problems associated with the multidrug therapy of non-insulin dependent diabetes mellitus. Methods High-dose metformin is difficult to formulate into a tablet dosage form due to its poor compressibility and compactibility. In this study, the way to overcome the difficulty was to utilize stearic alcohol to prepare the tablet formulation. The influences of viscosity, amount of HPMC, and weight of fillers were investigated. The optimal formulation had acceptable physicochemical properties and released metformin and glipizide over 10 h. Results The data of metformin obtained from in vitro release fitted Higuchi kinetics best, while the release of glipizide in vitro was found to follow zero kinetics. Conclusion Compound metformin/glipizide bilayer extended release tablets have been successfully developed.

Key words: metformin, metformin, glipizide, glipizide, extended release, extended release, bilayer tablet, bilayer tablet, stearic alcohol, stearic alcohol