RESUMO
The present work describes the application of the modified HPLC method for bioequivalence study of Rifampicin generic 300 mg capsules [generic] relative to Rifampicin innovator 300 mg capsules [reference]. A sensitive high pressure liquid chromatographic method for the quantitation of rifampicin in human plasma has been established by using water [pH 2.27]: methanol: acetonitrile [1.5:6:12] as a mobile phase. The method allows the analysis of rifampicin in plasma at concentrations ranging from 0.25 to 20 microg/ml. Linearity and precision of the method were validated by analysis of spiked human samples. Accuracy and precision of the method for rifampicin were found to be acceptable. Peak-area ratios [PAR] were used in the determination of plasma concentrations of the drug using indomethacin as an internal standard. The method is sensitive, therefore useful for routine analysis of large number of biological samples. The bioequivalence was carried out on twenty four healthy male volunteers who received a single dose of the test product, Rifampicin generic 300 mg capsules or, the reference product, Rifampicin innovator, 300 mg capsules, in a randomized balanced two ways cross over design. After dosing, serial blood samples were collected for a period of 24 hours. Pharmacokinetic analysis was performed using noncompartmental method. 90% confidence interval for AUC[0-inf], C[max] of test/reference ratio were found to be within the bioequivalence acceptance range of 80% - 125%. It was concluded that Rifampicin generic 300 mg capsules is bioequivalent to Rifampicin innovator 300 mg capsules