Assessment of quality control parameters and interchangeability of multisourced metformin HCl tablets marketed in Nigeria.

Abstract

A quality control assessment of five brands of metformin hydrochloride tablets marketed in Nigeria [Glucophage (R) (Merck, Quetta), Metformin BDC (Bangkok labs, Bangkok), Metformin (Medopharm, India), Glucophage (R) (Ilsan), Glucophage (Lipha)] was carried out in order to determine the brands that are interchangeable or switchable. The disintegration time, dissolution rate and absolute drug content were determined in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) without enzymes. The weight uniformity and hardness tests were also performed according to the official methods. A variation of the concept of dissolution efficiency (DE), known as predicted availability equivalent (PAE), was used to predict the likely in vivo bioavailability. Our results showed that all the five brands passed the uniformity of weight and disintegration tests. Dissolution efficiency was found to be higher in SGF than in SIF. In SGF, all the brands were bioequivalent. In SIF, all the brands, except Medopharm, were also bioequivalent. The study showed that four brands of metformin hydrochloride (Merck, BDC, Lipha and Ilsan) marketed in Nigeria are of acceptable standards and hence BDC, Lipha and Ilsan brands of glucophage are interchangeable with the innovator drug, glucophage R (Merck).