Comparative evaluation of quality attributes among six different brands of metformin hydrochloride tablets marketed in Bahir Dar city, Ethiopia

The prevalence of chronic disease such as diabetes is increasing in developing countries like Ethiopia. Metformin has been the most widely used first-line agent for the treatment of type II diabetes for more than 10 decades. Generic substitution is a common practice in community pharmacies. Therefore, ongoing bioequivalence evaluations are needed to ensure therapeutic equivalence among the brands. The main objective of this study is to evaluate and compare the common physicochemical properties and drug release profiles of six brands of metformin HCL 500 mg tablets available in community drug retailers in Bahir Dar city, Ethiopia. To achieve this objective, official and non-official compendial tests were conducted among the sampled brands. The results of the analysis demonstrated that all tested products complied with the specifications of the main test parameters as stipulated in the pharmacopoeias. Hence, the available brands can be regarded as acceptable substitutes for each other. However, an <i>in vivo</i> bioequivalence study may be needed for a final assessment of the similarity in efficacy of the generic formulations. Strict abidance to regulatory recommendations and progressive post-market surveillance are still required to promote the rational use of branded drugs and ensure safe and effective pharmacotherapy.