Simultaneous quantitation of Ofloxacin, Fexofenadine HCl and Diclofenac Potassium in affixed dose combinative formulation by HPLC-UV method

A high-pressure liquid chromatography (HPLC-UV) based simple and specific method for simultaneous quantitative determination of Ofloxacin, Fexofenadine HCl and Diclofenac Potassium has been developed and validated according to ICH guidelines. Chromatographic separation of the three drugs was carried out on 4.6 x 250mm x 5µ Licrospher RP Select B Column, using mobile phase constituted of methanol and phosphate buffer pH 3.5 (650: 350), pH adjusted to 3.5±0.05 with dilute ortho-phosphoric acid and delivered at a flow rate of 1ml/min. The eluents were detected at UV wavelength of 220nm and the retention times for Ofloxacin, Fexofenadine HCl and Diclofenac Potassium were 2.5 minutes, 4 minutes and 11.5 minutes, respectively. This method is suitable and specific for the three drugs and was found to be linear (R2>0.996), accurate, specific, reproducible and robust over a concentration range of 0.05 to 0.15mg/ml for Ofloxacin, 0.015 to 0.045mg/ml for Fexofenadine HCl and 0.0125 to 0.0375mg/ml for Diclofenac Potassium. The proposed method is simple and convenient, hence easily utilized for the characterization and quantitation of the three drugs in a single formulation for combination therapy of rheumatoid arthritis, sepsis, infection with fever and flu.