Abstract: An ion-pair reversed-phase high-performance liquid chromatographic method wasdeveloped for the determination of ciprofloxacin in human plasma. A reversed phase C18 Spherisorbcolumn (25 cm×4.6 mm, 5 μm) and a mobile phase of methanol-0.008 mol/L phosphate buffer-0.5mol/L tetrabutylammonium bromide (30:75:4, v/v/v, pH 2.6) were used. The detection wavelength was276 nm and the limit of detection was 40 ng/ml at a signal-to-noise ratio of 2. Protein preciptation wasaccomplished by the addition of acetoitrile. This procedure was used to study the pharmacokinetics of two preparations of ciprofloxacin in 8 volunteers upon oral administration, randomized crossover. There was no significant difference in pharmacokinetic parameters between the two preparations. The bioavailability of the syrup was 84% of that of the tablet.

Key words: Ciprofloxacin, High Performance Liquid Chromatography, Pharmacokinetics, Biological availability