High-Performance Liquid Chromatographic and First Derivative of the Ratio Spectrophotometric Determination of Amlodipine and Valsartan in Their Binary Mixtures

Abstract

Abstract Amlodipine besylate (AML) is a long-acting calcium channel blocker used as an antihypertensive agent. Valsartan (VAL) is also used to treat hypertension, either alone or in combination with other agents. Two-component mixtures of AML and VAL were analyzed by HPLC and the ratio spectra of the first derivative spectrophotometric technique. The spectrophotometric method depends on the first derivative of the ratio-spectra by measurements of the amplitudes at 234.0 nm for VAL and 351.0 nm for AML. Calibration graphs were established for 0.520 g/mL AML and 132 g/mL VAL using the ratio spectra of the first derivative spectrophotometric method. In the HPLC method, an ACE 5 C18 (4.6 150 mm, 5 m) RP column at 30C with the mobile phase methanolacetonitrileNaH2PO4H2O buffer, including 5 mL/L triethylamine and adjusted to pH 3.0 (42 + 18 + 40, v/v/v) at 2.0 mL/min flow rate was used to separate both compounds with detection at 254.0 nm. Linearity was obtained in the concentration range of 0.5500 g/mL for AML and 5.0900 g/mL for VAL. The proposed methods have been extensively validated. These methods allow a number of cost- and time-saving benefits. They were successfully applied to the determination of AML and VAL in synthetic mixtures and in a pharmaceutical dosage form. There was no significant difference between the performance of the proposed methods regarding the mean and SD values. The proposed methods are simple, rapid, and suitable for QC applications.