Application of Ratio Derivative Spectrophotometry for Simultaneous Determination of Clonazepam and Paroxetine Hydrochloride in Tablet Dosage Form

Abstract

Ratio derivative spectrophotometric method has been developed for the simultaneous estimation of Clonazepam and Paroxetine hydrochloride in pharmaceutical dosage form. In this method, the overlapping spectra of Clonazepam and Paroxetine hydrochloride were well resolved by making use of the first-derivative of the ratios of their direct absorption spectra. The derivative ratio absorbance of Clonazepam and Paroxetine hydrochloride were measured at 312.28 nm and 304.88 nm, respectively for their quantification. Clonazepam and Paroxetine hydrochloride were determined in the concentration range of 5-30 µg/ml and 10-60 µg/ml respectively. The linear regression analysis for the calibration plots produced r2= 0.9956 and r2= 0.9994 for Clonazepam and Paroxetine hydrochloride respectively. The precision, accuracy, limit of detection and limit of quantitation of the method were validated according to the ICH guidelines. The results indicate that the method is suitable for the routine quality control testing of marketed tablet formulations.