SIMULTANEOUS DETERMINATION OF OFLOXACIN AND CEFIXIME IN COMBINED TABLET DOSAGE FORM BY HPLC AND ABSORBANCE CORRECTION METHOD

High performance liquid chromatography and absorbance correction methods were developed and applied for the simultaneous determination of ofloxacin and cefixime. Chromatographic separation was achieved on reversed-phase C18 column(25 cm × 4.6 mm id, 5 μm) in the isocratic mode using methanol-water-triethylamine (25:75:1.5, v/v/v), pH adjusted to 3.50 ± 0.05 with orthophosphoric acid as the mobile phase at a flow rate 0.9 ml/min. Quantitation was achieved with UV detection at 254 nm. In the proposed HPLC method, quantification was achieved over the concentration range of 5-30 and 5-30 μg/ml, with mean recoveries of 99.95±1.31 and 100.36±1.24% for ofloxacin and cefixime respectively. In the absorbance correction method, quantification was achieved over the concentration range of 5-25 μg/ml for both drugs, with mean recoveries of 101.23±0.85 and 100.53±1.40% for ofloxacin and cefixime respectively. Determination was performed at 262.5 and 345.5 nm for ofloxacin and cefixime. The proposed methods were successfully applied for the analysis of synthetic mixtures and pharmaceutical formulations of ofloxacin and cefixime without any interference from common excipients. The results obtained by applying the proposed methods were statistically compared by the Student’s t-test.