目的 研究健康志愿者单次 po 不同剂量国产甲磺酸左氧氟沙星的药动学。方法 30名健康志愿者分3组 po 100，200，300 mg甲磺酸左氧氟沙星，血及尿药浓度均采用HPLC测定。数据用3P87药动学程序进行模型拟合并计算药动学参数。结果 甲磺酸左氧氟沙星药-时曲线符合二室模型，po 100，200，300 mg后其主要药动学参数：t_peak分别为1.287，1.121，1.386 h，t_1/2β分别为7.669，6.569，6.187 h，AUC分别为11.418，21.502，32.746 mg·h·L^-1，0～24 h尿药回收率分别为72.24%，66.31%，68.62%。主要药动学参数在3个剂量组之间无显著性差异。结论 国产甲磺酸左氧氟沙星在健康人体内的处置无剂量依赖性。本研究可为该药的临床应用提供一定科学依据。

OBJECTIVE To study pharmacokintics of domestic levofloxacin mesylate in healthy volunteers after oral administration of various dose. METHODS Thirty healthy volunteers were divided into 3 grops and given single oral dose of levofloxacin mesylate 100,200,300 mg.The levofloxacin concentrations in serum and urine were determined by HPLC methods.The 3P87(pharmacokinetics program) was used for analysis of metabolism process and parameters of kinetics. RESULTS It ws found that the serum concentrations-time curves were fitted to a two-compartment model.The main pharmacokinetic parameters were as following:t_peak(1.287±0.385) h,(1.121±0.316) h,(1.386±0.233) h;t_1/2β(7.669±1.697) h,(6.596±1.207) h,(6.187±0.972) h;and AUC(11.418±1.834) mg·h·L^-1,(21.502±4.805) mg·h·L^-1,and (32.764±3.564) mg·h·L^-1,respectively.There was no significant difference of main pharmacokinetic parameters among three dose groups. CONCLUSION The disposition of levofloxacin mesylate in healthy volunteers was dose-independent.This study will provide a scientific basis for the clinical applications.