Objective:To develop a method for the
determination of Pazufloxacin concentration in human urine.Methods: Separation was
performed on Kromasil C_(18) capillary column(250 mm×4.6 mm,5 μm).The mobile phase consisted of 3 mmol/L sodium dodecylsulphate(containing 0.5% triethylamine and adjusted to pH 4.0 with phosphoric acid)-acetonitrile(62∶38,V/V).The flow rate was 1.0 mL/min. The UV detection wavelength was at 242 nm.Results: A good linearity was obtained in the range of 1～300 mg/L with r=0.9998.The RSD of within-batch and between-batch variation of the method were both less than 10.0 %.The recoveries of three concentrations 1,30,300 mg/L were 94.0% ～95.3%.After being given an iv.administration of a single dose of Pazufloxacin
mesilate,the accumulative urine excretion rate of 12 volunteers during 24 hours was(90.3±2.6)%.Conclusion: This RP-HPLC method is simple,sensitive and accurate.It is suitable for the pharmacokinetic study of Pazufloxacin mesilate and its routine monitoring in human urine.