Pharmacokinetics and bioequivalence of levofloxacin in healthy Chinese subjects

Aim A randomized, two-way crossover study was conducted to determine the pharmacokinetics and bioequivalence of levofloxacin in 20 healthy Chinese male subjects under fasting conditions. Methods Levofloxacin test and reference tablets were administered as a single dose on two treatment days separated by a one-week washout period. After dosing, serial blood samples were collected for a period of 24 hr, and serum levofloxacin concentrations were determined by a validated reversed-phase high performance liquid chromatography (HPLC) assay and pharmacokinetic parameters were analyzed by the Drug and Statistics (DAS) Software. Results The serum concentration-time course followed a two-compartment open model. The main pharmacokinetic parameters of levofloxacin test and reference formulations were as follow: t1/2 were (7.37 ±0.88) h and (7.39 ±0.96) h,t max were (1.13 ±0.30) h and (1.06 ±0.24) h; Cmax were (2.08 ±0.42) mg·L and (2.03 ±0.35) mg·L, AUC0-24 were (13.17 ±2.32) mg·h·L and (13.73±2.89) mg·h·L,respectively. The relative bioavailability of test tablets was (97.7±16.7)%. No significant differences between the two formulations were found, and the parametric confidence intervals (90%) of the mean values of the pharmacokinetic characteristics for test/reference ratio were within the bioequivalence acceptable ranges of 0.8-1.25 and 0.70-1.43 respectively for AUC and Cmax. Conclusion The results indicate that the two tablet formulations of levofloxacin are equivalent in the rate and extent of absorption.