Stability Indicating RP- HPLC Method for Simultaneous Estimation of Valsartan and Amlodipine in Capsule Formulation.

Present work describes a precise, accurate and reproducible Reverse phase High Performance Liquid Chromatographic (RP-HPLC) method for simultaneous estimation of Amlodipine besylate (AMLB) and Valsartan (VAT) on RP C-18 Column (Kromasil, 250 x 4.6 mm) using acetonitrile: phosphate buffer (0.02M, pH 3.0), (56:44 v/v) as mobile phase at a flow rate of 1.0 ml/min and the detection wavelength was 234 nm. The retention time for AMLB and VAT was found to be 3.07 and 6.20 min, respectively. The method was also applied for the determination of AMLB and VAT in the presence of their degradation products formed under variety of stress conditions. Proposed method was validated for precision, accuracy, linearity range, robustness and ruggedness.