Simultaneous quantification of antofloxacin and its major metabolite in human urine by HPLC–MS/MS,and its application to a pharmacokinetic study

This study presents a high‐performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method for the simultaneous determination of antofloxacinin and its main metabolite – N ‐demethylated metabolite (N‐ DM) – in human urine. Ornidazole was used as the internal standard. This was a clinical urine recovery study, in which 10 healthy Chinese volunteers were intravenously administered a single 200 mg dose of antofloxacin hydrochloride. Compounds were extracted by albumen precipitation, after which samples were isocratically eluted using a Poroshell 120 SB‐C₁₈ column, and were analysed using HPLC–MS/MS under electronic spray ionization positive ion mode. The method was successfully applied in a urine pharmacokinetic study of antofloxacinin, with a detection range of 0.02/0.01 to 200/100 μg/mL (for antofioxacin/N‐ DM).The average percentages of antofioxacin/N‐ DM measured in urinary excretion frp, 10 volunteers were 54.9 ± 5.7/8.2 ± 2.5% in 120 h duration.     

左旋盐酸安妥沙星中对映体杂质的高效毛细管电泳法检测

建立了高效毛细管电泳检测盐酸安妥沙星中对映体杂质的方法。以含20 mmol/L HP-β-CD与70mmol/L磷酸二氢钾溶液(用磷酸调节pH3.0)为运行缓冲液,电压30 kV,柱温30℃,检测波长297 nm。可在10 min内将两对映体良好分离,检出限为2 mg.L-1(S/N=3),左旋安妥沙星在4.89~61.2 mg.L-1呈良好的线性关系,日内精密度(RSD)为2.1%(n=5),日间精密度(RSD)为3.2%(n=15)。