Stability indicating HPLC method for the simultaneous determination of ofloxacin and ketorolac tromethamine in pharmaceutical formulations

A simple, specific and accurate stability indicating liquid chromatographic method is established for simultaneous determination of ofloxacin and ketorolac tromethamine in bulk drugs and pharmaceutical formulations. Optimum chromatographic separations among ofloxacin, ketorolac and stress-induced degradation products have been achieved within 15 min by using a BDS Hypersil C8 column (250 x 4.6 mm, 5 mu m) as the stationary phase with methanol and phosphate buffer pH 3.0 (55 : 45 v/v) as the mobile phase at a flow rate of 0.8 mL min(-1). Detection is performed at 270 nm using a diode array detector. The method is validated in accordance with ICH guidelines. The response is a linear function of concentration over the range of 12-84 mu g mL(-1) for ofloxacin and 20-140 mu g mL-1 for ketorolac tromethamine. The method results in excellent separation of analytes and their stress induced degradation products with acceptable tailing and resolution. The peak purity index for both the analytes after all types of stress is >0.999 indicating complete separation of both analyte peaks from the stress induced degradation products. The method can therefore be regarded as stability-indicating. The developed method can be applied successfully for simultaneous determination of ofloxacin and ketorolac in pharmaceutical formulations and their stability studies.