Bioanalytical Method Development and Validation of Garenoxacin Mesylate in Human Plasma by RP-HPLC and Its Pharmacokinetic Application

A simple, precise, accurate RP-HPLC method was developed for the estimation of Garenoxacin mesylate in human plasma using Ciprofloxacin Hydrochloride as an internal standard. The chromatographic conditions optimized were Zorbax Eclipse XDB C18 (250 x 4.6 mm, 5
) column, Mobile phase 0.1% OrthoPhosphoric Acid and Acetonitrile in the ratio of 50:50 (% v/v) with a flow rate of 1.0 ml/min and injection volume of 50 µL. The detection wavelength was set to 240 nm with a column temperature of 30°C. The retention time of Garenoxacin mesylate was found to be 4.0 min. % Coefficient of Variation of Garenoxacin mesylate was found to be 4.30. % Recovery was obtained as 98.97%. The linearity of the proposed method was established in the concentration range of 0.04 to 4 µg/ml (Correlation Coefficient = 0.999). The lower limit of quantification was 0.04 µg/ml which reached the level of a drug possibly found in human plasma. Further, the reported method was validated as per the ICH guidelines and found to be well within the acceptable range. The method was successfully applied to a pharmacokinetic study after oral administration of immediate-release Zinox tablets (200 mg) in healthy Albino rabbits. The mean Cmax was found to be 5540 ng/ml, which occurred at a Tmax of 1.00 hr. The half-life and AUC0-
values were found to be 13.52 hr and 72187 ng. hr/ml. The method was found to be applicable to bioequivalence studies.