Biowaiver studies of Metronidazole tablets (400mg): An alternative to In-vivo bioequivalence Studies.

The aim of the study was to investigate the dissolution behavior of commercially available brands of metronidazole and to provide basic tool to evaluate the comparative effectiveness and interchangeability of generic brands under biowaiver conditions. The dissolution test for six brands of metronidazole 400mg tablets was performed and physical controls were analyzed. Basket Rack methods at 100rpm were used to estimate release pattern of drug. Pharmaceutical parameters of tablets were analyzed. In order to evaluate dissolution profiles, multiple point dissolution were performed and calculated 85.96±0.41 to 90.56±0.93 % within 15 minutes in pH 1.2,85.50±1.40 to 88.99±0.80% in pH 4.5 and 85.37±1.94 to 92.79±0.89% in pH 6.8 dissolution medium respectively. Five different kinetics have been studied to predict and evaluate the acceptability level of drug release. The results show that Hixson-Crowell, first-order and Weibull demonstrated the drug release with R> 0.95 that predicted the tablets were pharmaceutically equivalent. One-way ANOVA at p >0.05 level and similarity factors (f2) were used to estimate the discrepancy and intimacy among the brands. It is a need of time to constantly monitor the marketed generic drugs products and their release profiles to confirm their in vitro bioequivalence which can help to reduce the time, cost and unnecessary exposure of healthy subjects to medicines.