Ion-pair spectrophotometric estimation of gemifloxacin.

INTRODUCTION: The main objective was to develop and validate a simple, accurate, precise, and sensitive ion-pair spectrophotometric extraction method for the assay of gemifloxacin mesylate (GFX) in pure, tablets and spiked human urine.

MATERIALS AND METHODS: The method is based upon the reaction of gemifloxacin with methyl orange, forming a yellow-colored complex in acidic medium, which is extracted in chloroform and analyzed. The extracted complexes showed absorbance maxima (λmax) found to be at 427 nm.

RESULTS: Beer's law was obeyed for a wide concentration range, i.e., 10-80 μg/ mL as the extracted species seemed well defined and stable. The surface or an interphase adsorption phenomenon was not a problem. Optimization of the reaction was carried out with factors such as buffer strength, stability of complex, and molar ratio of drug: Dye and extraction time. The proposed method was validated as per the ICH guidelines. The recovery studies confirmed the accuracy and precision of the method.

CONCLUSION: The above-mentioned method was a rapid tool for routine analysis of GFX in the bulk and pharmaceutical dosage forms.