Voltammetric investigation of oxidation of zuclopenthixol and application to its determination in dosage forms and in drug dissolution studies

The oxidative voltammetric behaviour of zuclopenthixol (ZPT) at a glassy carbon has been studied using cyclic, linear sweep and differential pulse voltammetry. Oxidation of the drug produced three pH dependent anodic steps (representing an irreversible oxidation). Using differential pulse voltammetry, the drug yielded a well-defined voltammetric response in phosphate buffer, pH 5.2 at + 0.82 V (vs. Ag/AgCl). This process could be used to determine ZPT concentrations in the range 8 x 10(-7)-2 x 10(-4) M. The method was applied, without any interferences from the excipients, to the determination of the drug in tablets and oral drops, and in drug dissolution studies.