Spectrophotometric methods for simultaneous estimation of etoricoxib and thiocolchicoside in bulk and combined pharmaceutical dosage form

Simple, precise and economical spectrophotometric methods have been developed for the simultaneous estimation of Etoricoxib and Thiocolchicoside in bulk and combined tablet dosage form. The first method is based on the use of simultaneous equation, the second method is based on the simultaneous equation using AUC of the twodrugs, the third method is based on the use of absorbance ratio method and the fourth one is based on first order derivative method. Both the drugs obey the Beer’s law in the concentration ranges employed for these methods. The methods were validated by following the analytical performance parameters suggested by the InternationalConference on Harmonization. All validation parameters were within the acceptable range. The developed methods were successfully applied to estimate the amount of Etoricoxib and Thiocolchicoside in bulk and combined tablet dosage forms.