[Determination of rufloxacin in human plasma by high performance liquid chromatography]

A high performance liquid chromatographic method has been developed for the determination of rufloxacin in human plasma. Rufloxacin was extracted from plasma with dichloromethane for three times. It was chromatographed on an Ultrasphere ODS column with Pefloxacin as internal standard with a mobile phase consisting of methanol-tetrabutylammonium bromide-triethanolamine (32:68:0.5, V/V) adjusted to pH 2.8 with orthophosphoric acid. The flow rate was 1.2 mL/min and the monitoring wavelength was 295 nm. The calibration curve was linear from 0.1 to 10 mg/L of plasma. The detection limit of rufloxacin was 0.05 mg/L for plasma and the recovery was (97.7 +/- 2.1)%. The intra-day RSD and inter-day RSD were 2.33% and 3.38% respectively. The method is simple, rapid, accurate and can be used to determine the rufloxacin concentration in plasma and for pharmacokinetic study.