Quality assessment of nine brands of metformin hydrochloride tablets marketed in Abuja, Nigeria

Metformin is a drug of first choice in management of type II diabetes mellitus and the Nigerian market is flooded with many brands of metformin tablets. The aim of this study is to assess the pharmaceutical quality of nine brands of metformin tablets circulating in pharmacy outlets in Abuja. The brands were assessed for uniformity in weight, hardness, friability, disintegration time and in vitro dissolution using official methods. The content of active ingredient was also determined spectrophotometrically. All the brands had weights within the official limits, hardness was found to differ across the brands with values ranging between 1.20 and 11.50 kgF. Friability values were between 0.00 and 2.25%, disintegration time was between 2.06 and 10.36 min and within official specifications for film-coated tablets. Drug release within 60 min was between 93 and 103%, however, one of the brands fell outside the lower limit of the official specification and therefore, failed the dissolution test. Similarly, all but one of the brands were within the official specification of the percent content of active ingredient. The results highlight the need to routinely carry out market surveillance on drug products so as to safeguard the health of patients