Ion Selective Electrodes for Stability-Indicating Determination of Gemifloxacin Mesylate

Three novel polyvinyl chloride (PVC) membrane sensors for the determination of gemifoxacin mesylate are described and characterized. The sensors are based on the use of the ion association complexes of gemifoxacin cation with ammonium reineckate counter anions as ion exchange sites in the PVC matrix. The membranes incorporate ion association complexes of gemifoxacin with dibutylsebathete (sensor 1), dioctylphthalate (sensor 2), nitrophenyl octyl ether (sensor 3). The performance characteristics of these sensors were evaluated according to IUPAC recommendations, which reveal a fast, stable and linear response for gemifoxacin over the concentration range of 10-5-10-2 M for the three sensors with cationic slopes of -14.30, -20.44 and -22.37 mV per concentration decade for the three sensors, respectively. The proposed sensors displayed useful analytical characteristics for the determination of gemifoxacin mesylate in bulk powder, pharmaceutical formulation, and biological fluids (plasma) and in the presence of its acid degradation products and thus could be used for stability-indicating studies. Validation of the method shows suitability of the proposed sensors for use in the quality control assessment of gemifoxacin mesylate. The developed method was found to be simple, accurate and precise when compared with a manufacturer HPLC method.