[Pharmacokinetics and relative bioavailability study of roxithromycin tablet in Chinese healthy volunteers by LC-MS/MS].

This is a study of assessing the comparative bioavailability of roxithromycin produced by two companies in 36 healthy volunteers. On the basis of informed consent, 36 healthy male volunteers received each medicine at the roxithromycin dose of 150mg in a cross-over study. There was a 1-week washout period among the doses. Plasma concentrations of roxithromycin were monitored by an LC-MS/MS for over a period of 72 hours after administration. In this study, roxithromycin was generally well tolerated. After an oral administration of roxithromycin capsule, the pharmacokinetic parameters of roxithromycin, such as AUC(0-72 h) (66 076 microg x L x h(-1) and 70 334 microg x L x h(-1) for test and reference capsule, respectively) and AUC(0-infinity) (68 153 microg x L x h(-1) and 72 362 microg x L x h(-1)) were significantly similar. For test and reference capsule, the values of C(max) were 6 631.5 microg x L(-1) and 7 033.9 microg x L(-1) respectively, of T1/2 were 15.39 +/- 4.61 h and 16.06 +/- 5.56 h, and of T(max) were 1.3 +/- 0.9 h and 1.4 +/- 0.7 h respectively. The relative bioavailability F was 94.9% +/- 22.4% of tested formulation. The values of 90% confidence interval around the ratios (test/reference) (obtained by analysis of variance, ANOVA) were 88.3%-101.2% for C(max), 86.2%-98.9% for AUC(0-72) h, being within the predefined acceptable range for the conclusion of bioequivalence. The results of statistical analysis suggest that the two formulations be bioequivalent.