Bioequivalence of norfloxacin by HPLC-UV method

Abstract

A simple, rapid and convenient high performance liquid chromatographic method has been developed for the determination and bioequivalence of norfloxacin in tablets formulations by using ciprofloxacin as an internal standard. The chromatographic separation was achieved on a C18 column having an isocratic mixture of methanol, disodium hydrogen phosphate buffer and acetonitrile (30:30:40) at pH 3 adjusted with o-phosphoric acid. The eluents were detected at 280 nm and quantitation was achieved on the basis of peak height ratio of norflaoxacin and internal standard. Limit of detection of the method developed was 15 ng mL-1 with a linear range of 30-200 ng mL-1. After single oral dose (400 mg) of two formulations (Noroxin, MSD and Ecoflaxin, Technovision Pharmaceutical) of norfloxacin administered to healthy volunteers using a randomize 2×2 crossover design, pharmacokinetics parameters (AUC 0-t, AUC 0-∞, Cmax, t1/2) were derived from the plasma concentrations curves for both formulations. Pharmacokinetic analysis of the data showed that the two formulations were bioequivalent, while no adverse reactions to drug were observed. In addition, the method evolved has been found suitable for the routine quality control tests.