Study on the plasma level determination of gatifloxacin by HPLC

Objective: To establish HPLC method for determination of gatifloxacin in human plasma. Methods: The plasma protein was precipitated by the addition of 10%perchloric acid.The chromatography conditions were the column(Nova-PakC 3.9 × 150nm) and the which wrer 0.01mol· L phosphate buffer: acetonitrile: triethylamine=90:20:0.55 ( adjusted pH to 3.00 with phosphoric acid)as mobile phase.The flow rate was 1.0 mL · min .Detection wave length was 293nm.Ciprofloxacin was the internal standard. Results: The linear range of calibration curve was within drug plasma concentrations of 0.0574-5.508μ g·mL (r=0.9999), the detection limit concentration was 0.0574 μ g· mL, the recovery was98%-105%(n=5), the within-day RSD and between day RSD were within 10%(n=5), Conclusions: The method possesses merits of simplicity,sensitivity,good accuracy,high precision and fine reproducibility , which is suitable for the study of gatifloxacin in vivo.