Abstract

This work was aimed at evaluating the properties of metronidazole capsules and tablets formulated by different methods in comparison with some commercially available tablet brands to ascertain the influence of formulation parameters and the unpopularity of clinical use of the capsule in Nigeria. Three batches of metronidazole 200 mg tablets were formulated by wet granulation, dry granulation and direct compression methods. Metronidazole 200 mg capsules were formulated by hand filling technique. The formulations and two commercially available tablet brands (M & B, Cardinal) were evaluated following standard procedures. All the formulated tablets passed the uniformity of weight and content, disintegration and dissolution tests but failed the friability test to a significant degree in the order: Dry > Direct Compression > Wet. The release profiles were in the order: Wet > Direct Compression > Dry > M & B > Capsule > Cardinal, with significant (P < 0.05) difference between the highest and the lowest. The results indicated that variations in formulation parameters had important influence on the qualities of solid dosage formulations of metronidazole. Except for one commercial brand, all the tablet formulations tested generally performed better than the capsule formulation, probably supporting its unpopularity in Nigeria.

Key words: Metronidazole, capsules, tablets, granulation, dissolution profile.