Brand variations in the physicochemical properties of metronidazole tablets

This study investigated possible variations in the physiochemical properties of seven brands of metronidazole tablets obtained from different retail pharmacy outlets in Nigeria. The different brands were subjected to various tests such as uniformity of weight, crushing strength, friability, disintegration and dissolution. Chemical assays were also carried out on the tablets. Five of the seven brands of metronidazole tablets passed all British Pharmacopoeia tests; while brand G failed the chemical assay test and brand A failed both the chemical assay and test for friability. Brand A also had the lowest crushing strength which was below the recommended minimum. There was a significant difference (p < 0.001) in the values obtained for the crushing strength of the various brands while no significant difference (p > 0.05) in the friability values. The results show that five of the seven brands are physically and chemically equivalent and could be interchanged irrespective of the brands, while two cannot. The study reinforces the need for constant monitoring of different brands of the same product to ensure quality and consequent efficacy.