New Spectrophotometric Methods for Simultaneous Determination of Amlodipine besylate and Benazepril in Tablet Dosage Forms

Two simple, accurate, precise, reproducible, requiring no prior separation and economical procedures for simultaneous estimation of Amlodipine besylate (AML) and Benazepril (BEN) in tablet dosage form have been developed. The first method is simultaneous equation method; in this method 360.0 nm and 240.0 nm were selected to measure the absorbance of drugs at both wavelengths. The second method is Q-value analysis based on measurement of absorptivity at 227.50 nm (as an iso-absorptive point) and 360.0 nm at maximum wavelength of AML, 360.0 nm and at isoabsorptive point 227.50 nm both AML and BEN shows linearity in a concentration range of 5-40 µg/mL. Recovery studies range from >99.41% for AMD and >98.93% for BEN in case of simultaneous equation method and >100% for AMD and >99.55% for BEN in case of Q-analysis method confirming the accuracy of the proposed method. The proposed methods are recommended for routine analysis since it is rapid, simple, accurate and also sensitive and specific (no heating and no organic solvent extraction is required).