Pharmacokinetics of antofloxacin hydrochloride, a new fluoroquinolone antibiotic, after single oral dose administration in Chinese healthy male volunteers

Antofloxacin hydrochloride is a newly developed fluoroquinolone antibacterial in China, which has comparable in vitro and animal pharmacological and toxicological properties to levofloxacin and is worthy of further clinical trial. Human tolerance of single escalating doses from 50 to 500 mg was shown to be safe. The purpose of the present study was to evaluate the pharmacokinetic characteristics of a single oral dose of antofloxacin hydrochloride in Chinese healthy male volunteers. Twelve subjects were randomized for administration of a single dose of 300, 400 and 500 mg antofloxacin hydrochloride in a 3-way crossover design. High pressure liquid chromatography (HPLC) was used to assay the serum and urine concentrations of antofloxacin in samples collected over a period of 72 h following drug administration. All three dosages were well tolerated. Antofloxacin hydrochloride demonstrated linear pharmacokinetic characteristics with mean pharmacokinetic values varying from 0.09 to 0.10 l/h/kg for CL/F and from 2.75-3.00 l/kg for V/F. The t(1/2beta) was around 20 h and the mean fraction of dose excreted in urine varied from 0.40 to 0.46. Based on these data, 300 mg of antofloxacin hydrochloride administered once daily was selected for further investigation in a multiple dose administration study.