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 ca rbon has been studied using cyclic, linear sweep and differential pulse vol tammetry. Oxidation of the drug produced three pH dependent anodic steps (r epresenting an irreversible oxidation). Using differential pulse voltammetr y, the drug yielded a well-defined voltammetric response in phosphate buffe r, pH 5.2 atf 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 ap plied, without any interferences from the excipients, to the determination of the drug in tablets and oral drops, and in drug dissolution studies. (C) 2000 Elsevier Science B.V. All rights reserved.