Development and validation of UV-Visible spectrophotometric baseline manipulation methodology for simultaneous analysis of drotraverine and etoricoxib in pharmaceutical dosage forms.

Introduction: A simple, economical, precise, and accurate new UV spectrophotometric baseline manipulation methodology for simultaneous determination of drotaverine (DRT) and etoricoxib (ETR) in a combined tablet dosage form has been developed.

Materials And Methods: The method is based on baseline manipulation (difference) spectroscopy where the amplitudes at 274 and 351 nm were selected to determine ETR and DRT, respectively, in combined formulation and methanol was used as solvent. Both the drugs obey Beer's law in the concentration ranges of 4-20 μg/mL for DRT and 4.