Electrochemical Study of Zolpidem at Glassy Carbon Electrode and Its Determination in a Tablet Dosage Form by Differential Pulse Voltammetry

Abstract

The oxidative behaviour of, a hypnotic drug, zolpidem was studied at glassy carbon electrode in Britton–Robinson buffer over the pH range 2.0—11.0 using cyclic, linear sweep and differential pulse voltammetry. Oxidation of the drug was effected in a single irreversible, diffusion-controlled step. Using differential pulse voltammetry (DPV), the drug yielded a well-defined voltammetric response in Britton–Robinson buffer, pH 8.0 at +0.889 V (vs. Ag/AgCl) on glassy carbon electrode. This process could be used to determine zolpidem concentrations in the range 5.0×10⁻⁷ M to 1.0×10⁻⁵ M with a detection limit of 2.0×10⁻⁷ M. The method was applied, without any interference from the excipients, to the determination of the drug in a tablet dosage form.