Modification and validation of liquid chromatographic method for the quantification of ciprofloxacin in human plasma and its application to a bioavailability study.

A new simple, accurate, precise and sensitive liquid chromatographic method for the analysis of Ciprofloxacin in human plasma, suitable for quantification of drug was developed and validated using HPLC-UV method. The analyte was chromatographically separated from endogenous plasma components on a C-18 reversed phase column (5µm, 25cm × 0.46cm) and detected at 278nm. The sample pretreatment was carried out with acetonitrile on 200µl of plasma. The Lower limit of quantification (LLOQ) was 0.04 µg/ml with linearity in the range 0.04-4 µg/ml and coefficient of correlation value (R)>0.995. The method was successfully validated as per current FDA guidance for necessary parameters and applied to a pilot bioavailability study conducted on six healthy volunteers with marketed Ciprofloxacin 250mg immediate release tablets. The plasma concentrations were subjected to non-compartmental analysis for calculation of pharmacokinetic parameters like C, T, AUC, AUC and t etc. The mean values of C and T were found to be 1.35±0.09µg/ml and 1.25±0.27h respectively while for other pharmacokinetic parameters including AUC, AUC were found to be 5.98±0.96 μg/ml×h and 6.34±1.07μg/ml×h. The drug exhibited half-life (t) of 3.94±0.33h. The obtained results proved the suitability of the method for routine pharmacokinetic studies of Ciprofloxacin.