HPLC Method For Simultaneous Estimation Of Rofecoxib And Tizanidine Hydrochloride In Tablets
A reverse phase high performance liquid chromatography method for the simultaneous estimation of rofecoxib and tizanidine hydrochloride in tablets is developed. The determination was carried out on a Wakosil C18 (250x4.6mm, 5 Î¼m) column using a mobile phase of acetonitrile and phosphate buffer pH 5.0 (50:50%v/v). The flow rate was 0.5 ml/min with detection at 240 nm. The retention time for tizanidine hydrochloride was 4.9 min and rofecoxib 12.2 min. Rofecoxib showed a linear response in the concentration range of 50-200 Î¼g/ml and tizanidine hydrochloride 10-80 Î¼g/ml. The results of analysis have been validated statistically and by recovery studies. The recoveries obtained for standard rofecoxib and tizanidine hydrochloride from the formulation ranged from were 98.20 to 101.6%.