Post-market in-vitro comparative studies of different brands of metformin tablets available in Libya

Metformin hydrochloride is the first-line anti-diabetic drug used to treat type 2 diabetes mellites and helps to control blood sugar levels. Various brands of metformin are available in the Libyan market which makes it challenging to select, an effective and economical one. This study aimed to compare different brands of metformin available in the Misurata and evaluate the quality parameter according to the British Pharmacopoeia. Six brands of metformin tablets (850 mg) were taken from the market and assessed. To achieve this purpose five tests were done on each brand, the uniformity of weight test shows the average weight and 5.0% deviation, the friability test gives how much the tablet can stand attrition, the disintegration time test shows the time taken by the tablet to disintegrate, dissolution test to confirm the rate of drug release, weight variation and friability test of all brands was within the specified limit. Disintegration time for all the brands was within 30 minutes. All six brands of metformin hydrochloride tablets fulfilled the in-vitro dissolution rate test specification not less than 80% of the drug is released within 45 minutes. Using Ultraviolet-visible (UV) spectroscopy, UV analysis of different samples shows that the percentage content of active ingredients of five brands of metformin hydrochloride tablets was within the monograph specification (95%-105%) of drug content but one brand failed this test. The study indicated that strict quality control of imported drugs should enforced to ensure effective and safe medicines in the Libyan market.