Abstract

A reverse phase high performance liquid chromatography method for the simultaneous estimation of tizanidine hydrochloride and nimesulide in tablets is presented. Cynopropyl column is used to retain tizanidine hydrochloride (k`=1.52) and also have reasonable retention for nimesulide (k`=2.37) with a good resolution and peak symmetry. Effect of change of chromatographic conditions such as pH, %organic modifier (acetonitrile) in mobile phase on retention of drugs were studied and optimized. Both the drugs showed linear response in the concentration range employed (tizanidine hydrochloride, 1.2-2.8 μg/ml and nimesulide, 60-140 μg/ml) and was validated by least squares method at 95% confidence level. The results of analysis have been validated statistically and by recovery studies. The mean recoveries obtained for tizanidine hydrochloride and nimesulide were 99.6% and 100.1%, respectively.