Formulation of Sustained Release Metformin Hydrochloride Matrix Tablets: Influence of Hydrophilic Polymers on the Release Rate And In Vitro Evaluation

Metformin HCL, the only available biguanide, remains the first line drug therapy for patients with Type 2 diabetes mellitus acts by decreasing hepatic glucose output and peripheral insulin resistance. It has relatively short plasma half life, low absolute bioavailability. The overall objective of the present work was to develop an oral sustained release metformin tablet prepared by direct compression method, using hydrophilic hydroxyl propyl methylcellulose and Xanthan gum polymer as rate controlling factor. All the batches were evaluated for thickness, weight variation, hardness, and drug content uniformity and in vitro drug release. Mean dissolution time is used to characterize drug release rate from a dosage form and indicates the drug release retarding efficiency of polymer. Hydrophilic matrix of HPMC alone could not control the Metformin release effectively for 12 h whereas when combined with Xanthan gum could slow down the release of drug and can be successfully employed for formulating sustained-release matrix tablets. Fitting the data to Korsmeyer equation indicated that diffusion along with erosion could be the mechanism of drug release.Similarity factor, ƒ2 values suggest that the test and reference profile are identical. © 2011 Universal Research Publications. All rights reserved