Abstract: Aim The pharmacokinetics of lomefloxacin hydrochloride administered orally or by dripping in infected patients was studed. Methods The parameters with different dosages, fasting and non-fasting, single and multiple dsoes were compared. A hing performance liquid chromatography was used to determine the concentration of lomefloxacin in serum and urine. Results A first-order absorption and an open dubble compartment pharmacokinetics model were showed after taking the drug. When a single oral dose of 200 mg of lomefloxacin was gaven to the patiens before and after breakfast, the absorption was slightly decreased. The T_{1/2 ka} was 0.39±0.18 and 0.47±0.20 h,the T_max was 1.3±0.3 and 1.6±0.4 h respectively,but the C_max had no significant difference between before and after food. After a single oral dose of 200,400, and 600 mg of lomefloxacin, pharma-cokinetic parameters for the drug were T_1/2β was 9.8±2.9,10.7±4.0 and 11.2±3.9 h, C_max was 1.5±0.4, 2.4±0.8 and 3.8±0.9 mg·L^-1, respectively. The AUC_0-∞ were pro-portional to dose and the pharmacokinetics had a linear relationship with dose. The C_max was 3.1±0.9 mg·L^-1 after a single drip dose of 600 mg of lomefloxacin. Compared with those in the single dose, the C_max and AUC_0-∞ had marked increase with a retaining factor of 1.45 after multiple oraling dose of 400 mg twice daily for 7 days. But the parameter had no significant change with a retaining factor 1.10 after dripping 600 mg once daily for 7 days. The percentage of prototype drug urinary recovery within 24 hours was about 50% in all methods and dosages of taking drug. Conclusion Lomefloxacin is a drug that has a linear pharmacokinetic.

Key words: lomefloxacin, pharmacokinetic, high performance liquid chromatography