Quality control evaluation and dissolution performance comparison of marketed metformin hydrochloride tablets in Mekelle, Ethiopia: identifying substandard formulations

Poor-quality medicines are a global issue, more severe in conflict-affected regions, like Tigray (Ethiopia). Furthermore, this situation in particular has worsened for chronic illness, such as diabetic type-2 patients. This study aims to assess and compare the quality of ten different products of metformin hydrochloride (HCl) 500 mg and 850 mg strength tablets marketed in Mekelle City, Ethiopia. Official Pharmacopeia quality parameter tests such as physical characteristics, dissolution, disintegration, weight variation, assay, and hardness tests were conducted to evaluate the in vitro quality of different commercially available tablets of metformin HCl immediate-release (IR) tablets. Data were analyzed using Origin Pro 2024 and one-way analysis of variance. Except for one product, they all had online Ethiopia Food and Drug Authority registration numbers. For a 500 mg metformin HCl tablet, weight variation ranged from − 3.96% to 2.22%, assay value ranged from 95.2% to 102.1%, and dissolution value ranged from 90.4% to 99.7% at 45 min. For an 850 mg metformin hydrochloride tablet, weight variation ranged from − 2.1% to 2.6%, assay value ranged from 97.9% to 103.7%, and dissolution value ranged from 97.9% to 101.6% at 45 min. In addition, three of the tested commercially available tablets did not meet the disintegration limit. Overall, these findings highlight the need for regular quality measurement to control substandard or falsified metformin HCl IR product in the market, particularly in the post-war regions such as Tigray.