Derivative spectrophotometry method for simultaneous estimation of rupatadine and montelukast in their combined dosage form

This study describes the development and validation for the simultaneous estimation of rupatadine and montelukast by the Þ rst-order derivative UV spectroscopy method. The quantiÞ cation was achieved by the Þ rstorder derivative spectroscopy method at 273.46 nm and 297.27 nm over the concentration range of 5-25 µg/ ml for estimation of rupatadine and montelukast in a combined tablet formulation. Procedure does not require prior separation of components from the sample. Rupatadine and montelukast were determined at 15 µg/ml with a mean recovery of 99.59 + 0.225 and 99.21 + 0.76, respectively. Calibration curves were linear with a correlation coefÞ cient of 0.9994 and 0.9992 for rupatadine and montelukast, respectively. The relative standard deviation was found to be