Simultaneous determination of Ciprofloxacin and the active metabolite of Prulifloxacin in aqueous human humor by high-performance liquid chromatography

A rapid and simple method for determining two fluoroquinolones (FQNs), namely Ciprofloxacin and Ulifloxacin, this being the last active metabolite of Prulifloxacin, in aqueous human humor (AHH) has been developed and validated. The calibration data resulted linearly correlated in the 4-500 ng/mL concentration range with 8 ng/mL lower limit of quantification (LLOQ) for Ciprofloxacin, and 5-600 ng/mL concentration range with 6 ng/mL LOD for Ulifloxacin. The proposed analytic procedure has been validated by testing quality control sample (QCS) of AHH probed with the two FQNs at 10, 50, 500, and 1000 ng/mL concentration values. Validation of the method has been checked by accuracy and precision data of intra-day and long-term experiments. The two FQN concentrations have been measured by HPLC technique with UV detection at 278-nm wavelength for the AHH of patients to whom were supplied oral doses of FQNs (500 mg) twice in a day, within 1-24 h before the surgery intervention of cataract. The average concentration of Ciprofloxacin resulted 186 ng/mL and that of Ulifloxacin 78 ng/mL. The nice quality of the proposed analytic procedure means that it may be suitable for in vivo studies of pharmacokinetics regarding these substances in the AHH medium.