Abstract: AIM: To evaluate the pharmacokinetic profiles and the bioequivalence of domestic gatifloxacin in Chinese male volunteers. METHODS: 24 healthy male volunteers received a single 400 mg dose of domestic or imported tablet of gatifloxacin in a randomized and twoway crossover design.The drug concentrations in plasma and urine were measured by HPLC method. RESULTS: The pharmacokinetics of gatifloxacin was fitted into twocompartment model after a single oral dose of 400 mg domestic and imported tablet in 24 healthy volunteers.The mean peak concentration (C_max), median peak time (T_max), elimination half-life (T_{1 2β ) and area under the curve (AUC0~∞ ) in plasma were 4.45 ±1.04 and 4.05 ±0.85 mg·L^-1, 0.75(0.5, 3) h and 0.75(0.5, 2.5) h, 6.97 ±1.08 and 7.19 ±0.91 h, 31.99 ±3.80 and 32.11±3.37 mg·h·L^-1, respectively.The cumulative urinary excretion rates within 48 h were (79.47 ± 6.00) %and (79.59 ±5.89) %.Compared with imported tablet, the differences of the main pharmacokinetic parameters were not statistically significant (P >0.05). The relative bioavailability of domestic gatifloxicin tablet was (99.74 ±7.42) %. CONCLUSION: The effective concentration maintained in plasma is longer and the cumulative urinary excretion rate is higher after a single oral dose of domestic tablet of gatifloxacin and it was equivalent to that of imported gatifloxacin.}

Key words: gatifloxacin, pharmacokinetic, bioequivalence, HPLC, volunteers