A validated rp-hplc method for simultaneous estimation of tizanidine and nimesulide in bulk and pharmaceutical formulation

A simple, exceptionally cost-effective, extremely accurate, quite precise and highly reproducible method was developed and validated for simultaneous estimation of Tizanidine and Nimesulide in bulk and Pharmaceutical formulation.

The separation has been done on Reverse Phase C18, 250X4.6 mm, 5μ column (40°C temperature). The mobile phase contain acetonitrile and water (ACN:WATER) (60:40).pH 4.5with ortho phosphoric acid(OPA), the flow rate was set at 1.0ml/min, and UV detection at 305nm, mobile phase was sonicated for 25 min. before use.

The retention times were obtained at 6.309min.and 2.492min. for Nimesulide and Tizanidine respectively. With accuracy of less than 2%, LOQ for Nimesulide and Tizanidine were found as 29.75μg/ml and 0.9649μg/ml respectively similarly LOD was 9.79μg/ml and 0.3184μg/ml. Precision % RSD for intraday and interday were found as 0.2 and 0.64 for Tizanidine, 0.68 and 0.63 for Nimesulide. Linearity was found in the range of 10–50μg/ml and 0.2–10μg/ml for Nimesulide and Tizanidine respectively. The method was found robust for changes in the flow rate, ratio of mobile phase and detection wavelength.

The method was found to be satisfactory and can be used successfully for determination of Tizanidine and Nimesulide simultaneously in bulk and pharmaceutical dosage form.