Formulation and in vitro evaluation of Metformin HCl mucoadhesive tablets for NIDDM

The objective of the present work was to develop an oral Mucoadhesive Metformin hydrochloride tablet for the sustained-release. Metformin hydrochloride (HCl), a biguanide, has a relatively short plasma half-life and low absolute bioavailability. The tablets were prepared by the Wet Granulation method, using biodegradable mucoadhesive polymer Xanthan gum and pectin at different concentrations. All the batches were evaluated for thickness, weight variation, hardness, drug content uniformity, in vitro drug release and mucoadhesion strength. Mean dissolution time is used to characterize the drug release rate from a dosage form, and indicates the drug release-retarding efficiency of the polymer. The in vitro studies the formulations containing Pectin showed less retardation than the formulation with Xanthan gum. The Metformin release effectively controlled for 12 h with Xanthan gum, thus, can be successfully employed for formulating mucoadhesive tablets. Fitting the data to the Zero order and Higuchi equation indicated the mechanism of drug release. The study reveals that Xanthan gum highest mucoadhesive strength compared with pectin.