Determination of Metformin Hydrochloride in Different Brands of Tablets Commercially Available in the Libyan Pharmaceutical Market

Metformin hydrochloride is an oral hypoglycemic drug used to treat type 2 diabetes mellitus and belongs to the class of Biguanides. This study assessed and compared the pharmaceutical quality of four brands of metformin hydrochloride tablets produced by different manufacturers and available in the Libyan pharmaceutical market, using United States Pharmacopoeia (USP) specifications as the reference standard. The active pharmaceutical ingredient content was quantified using ultraviolet–visible (UV–Vis) spectrophotometry. Assay values ranged from 83.3% to 100% of the labelled content. Three brands met the USP acceptance criteria, whereas one did not comply with the specified requirement. These findings indicate that the evaluated products varied in their compliance with pharmacopeial standards and highlight the need for regular post-marketing quality surveillance to identify substandard medicines and support patient safety.