Spectrophotometric determination of fleroxacin in tablets

Abstract

Fleroxacin belongs to the third genegation of multiple fluorinated antibacterial quinolone derivatives widely used in the treatment of urinary infections. In aqueous medium fleroxacin undergoes to complex acid-base equilibrium due to its zwitter ioninc nature and two ionizable functional groups of similar acidity. The corresponding ionization constants were determined by potentiometry and spectrophotometry. On the basis of the knowledge of distribution and spectral characteristics of ionic species of fleroxacin the spectrophotometric method for determination of fleroxacin was developed. The assay was carried out in acidic media (0.1 M HCl) at a wavelenght of 286 nm. A calibration graph was obtained for fleroxacin concentrations 2-8 μg/ml with correlation coefficient a 0.9999. The method is simple and rapid, and was successfully applied to the determination of fleroxacin in commercial tablets.