Evaluation of the quality and in vitro pharmaceutical equivalence of generic metronidazole tablet brands marketed in Kenya

Metronidazole is one of the most affordable, accessible and prescribed antimicrobials. It is included in the Essential Medicines List by the World Health Organization due to its pivotal role in public health. This study sought to evaluate the quality and pharmaceutical equivalence of generic metronidazole tablet brands marketed in Kenya. Nine metronidazole tablet brands were subjected to standard physicochemical tests for identity, uniformity of weight, friability, hardness, disintegration, assay, and dissolution as specified by the British Pharmacopoeia and the United States Pharmacopeia. The dissolution data of the eight generic brands were compared to that of the innovator brand using fit factors f1 and f2, and dissolution efficiency. All the nine metronidazole tablet brands complied with the tests for identity, friability, hardness, disintegration, and dissolution. One brand (11.1%) failed the test for uniformity of weight, while four brands (44.4%) did not meet the compendial limits for assay with values less than 95.0% label claim. The analyzed metronidazole tablet brands had similar drug release profiles and may therefore be considered pharmaceutical equivalents. Although most of the generic metronidazole tablet brands analyzed in this study are of the required quality, regular post-marketing surveillance is recommended to ensure that non-compliant pharmaceutical products are flagged and corrective actions instituted.