Electrochemical Reduction behaviour of Donepezil at β-Cyclodextrin Modified Carbon Paste Electrode

A simple, accurate and sensitive voltammetric method for determination of donepezil (DNZ) using β-cyclodextrin modified carbon paste electrode (CDMCPE) is developed. CDMCPE exhibited significantly increased sensitivity and selectivity for DNZ compared to the bare carbon paste electrode (CPE). Effect of accumulation potential, accumulation time, pH of buffer, etc., on peak currents for the determination of DNZ was studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Peak currents showed a linear response in the concentration range 4.2 x 10-8 to 5.6 x10-7 M and 3.2 x 10-9 to 4.2 x 10-8 M at CPE and CDMCPE respectively. Limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.2 x 10-9 and 0.40 x 10-8 M. The proposed method has been successfully applied for the determination of DNZ in spiked urine samples, serum samples and pharmaceutical formulations.