Fast and sensitive simultaneous determination of antihypertensive drugs amlodipine besylate and ramipril using an electrochemical method: application to pharmaceuticals and blood serum samples

Abstract

In this work, a simple and sensitive voltammetric method for simultaneous determination of antihypertensive drugs amlodipine besylate (AML) and ramipril (RMP) is described. A cathodically pretreated boron-doped diamond electrode (CP-BDDE) was employed wherein AML and RMP were irreversibly oxidized at 0.68 and 1.70 V (vs. Ag/AgCl (3.0 mol L⁻¹ KCl)), respectively, in Britton–Robinson buffer solution (pH 6.0). Under optimized instrumental parameters of differential pulse voltammetry, the oxidation current of AML and RMP linearly increased in the concentration range of of 0.99–14 and 0.29–1.9 μmol L⁻¹, obtaining limits of detection of 0.26 and 0.08 μmol L⁻¹, respectively. The feasibility of the proposed method was successfully assessed by simultaneous quantification of these drugs in commercially available pharmaceutical formulations and rat blood serum samples. The results obtained further verify the fact that the CP-BDDE coupled with the differential pulse voltammetric technique may constitute an electroanalytical platform for fast simultaneous determination of these analytes in pharmaceutical formulations and biological samples.