Samar Afifi

Pharmaceutics Department, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.

Abstract:

The aim of the present study was the evaluation and comparison between six different Metformin hydrochloride brands which are commercially available in the Saudi Arabia market. The physicochemical equivalence of six brands of Metformin hydrochloride tablets were determined through the evaluation of both official and non-official standards according to the USP pharmacopoeia including uniformity of weight, friability, hardness, disintegration, dissolution rate and drug content. A variation of the concept of dissolution efficiency (DE), known as predicted availability equivalent (PAE), was used to predict the likely in vivo bioavailability. All the tested six brands were bioequivalent and complying with the official tests for weight variation, friability, disintegration and dissolution tests. The friability test was within the specified limit. All formulations were disintegrated within 15-30 min. The tested brands were identical according to their dissolution evaluation. Only Glucare® was nonequivalent to the innovator Glucophage®. The percentage content of active ingredient of six brands of Metformin tablets showed values within the monograph specifications (95-105%). All the six brands evaluated in this study could be considered biopharmaceutically and chemically equivalent and therefore they can be substituted with the innovator product in clinical practice except Glucare®. Therefore, patients can safely switch from one brand to another.

Keywords: Dissolution test, Metformin hydrochloride and Quality control of tablets.