Electrochemical analysis of amlodipine in some pharmaceutical formulations and biological fluid using disposable pencil graphite electrode

Abstract

A reproducible and sensitive voltammetric procedure has been developed for the determination of amlodipine (AML) by using pencil graphite electrode (PGE) as working electrode. The experimental parameters, such as concentration, pH, amplitude, frequency, deposition potential were optimized and the peak potential was found to be 700mV [vs. Ag/AgCl], by square-wave voltammetry (SWV) and differential pulse voltammetry (DPV). Under optimized conditions in Britton–Robinson buffer (pH8.5), linear calibration curve was obtained in the range of 0.8nM–51.2nM solution. The limit of detection (LOD) and limit of quantification (LOQ) for SWV and DPV were calculated 0.02pM, 0.04pM, 0.06pM and 0.2pM respectively. The proposed method was used to estimate the amount of drug in different brands of pharmaceutical formulations with almost 99.9% recovery. Developed method was also applied for the detection of AML in spiked human serum with good recovery of almost 99% and limit of detection was found to be 0.21pM. The proposed methodology is first attempt to develop a method on PGE which represents an effective, cheap, easily available and alternative tool instead of commonly used glassy carbon and other chemically modified electrodes for the electrochemical determination of amlodipine.