Simultaneous Determination of Valsartan and Amlodipine Besylate in Human Serum and Pharmaceutical Dosage Forms by Voltammetry

Abstract

Anodic behavior of binary mixture of amlodipine besylate (AMD) and valsartan (VAL) was studied on glassy carbon electrode based on the irreversible oxidation signal of AMD at 0.95 V and that of VAL at 1.15 V versus Ag/AgCl at pH 5.0 in Britton-Robinson buffer. Differential pulse voltammetric method was proposed to direct determination of AMD and VAL in pharmaceuticals and spiked human serum. Linearity for AMD was in the range from 1.0 mu M to 35.0 mu M and that for VAL was in the range from 1.5 mu M to 32.0 mu M when concentrations of AMD and VAL are increased simultaneously. Limit of detection and limit of quantification were found to be 0.31 mu M and 1.03 mu M, for AMD and 0.36 mu M and 1.21 mu M for VAL, respectively. The method was successfully applied with good recoveries between 90.8 % and 100.4 % with relative standard deviation less than 10 % for tablet samples and around 15 % for serum samples.