UV spectrophotometric method for simultaneous estimation of tizanidine and valdecoxib in tablet dosage forms

Abstract

The simple, selective, rapid and precise UV spectrophotometric method has been developed for the simultaneous estimation of valdecoxib and tizanidine in pharmaceutical dosage form. The proposed method is based on the Vierodt's simultaneous equations. Tizanidine has absorption maxima at 318.1 nm and valdecoxib absorption maxima at 239.0 nm in methanol. The linearity was observed in the concentration range of 2-18 μg/ml for tizanidine and valdecoxib. Both the drugs obey Beer's law. The method is validated statistically. The recovery studies confirmed the accuracy of the proposed method.