Assay of Amlodipine Besylate in Tablets and Human Biological Fluids by Square Wave Adsorptive Cathodic Stripping Voltammetry

Abstract

The adsorption behavior of the antihypertensive and antianginal agent amlodipine besylate onto a Hanging Mercury Dropping Electrode (HMDE) was explored by square wave and cyclic voltammetry. The drug accumulated at HMDE and a well-defined peak was obtained at –1.73V versus Ag/AgCl (saturated KCl) in phosphate buffer at   pH 7. A validated simple, rapid and sensitive square-wave voltammetric procedure was described for direct determination of the authentic cited drug. The optimum procedure conditions were accumulation potential Eacc. = –1.1V, accumulation time tacc. = 60s, wave amplitude = 100mV, wave increment = 12mV and frequency = 100 Hz. Limits of detection (LOD) and quantification (LOQ) of 3.61×10–11M and 1.2×10–10M were achieved, respectively. The developed method was standardized for the determination of the drug in pharmaceutical formulation (amlodipine and myodura tablets) for quality control purposes. The observed data were subjected to statistical analysis, which revealed high reliability and precision. The intra-day relative standard deviation RSDs ranged from 0.331 to 0.418% at three different concentrations and inter-day RSDs ranged from 0.055 to 0.271%. The procedure was successfully applied to the quantification of the drug in human urine and serum samples. The mean percentage recoveries were 99.5±0.58 and 99.7±0.96 in human urine and serum sample, respectively. The proposed method was found to be suitable for the assay of amlodipine besylate in the presence of some common excipients and hence it can be consider specific.