Electroanalytical Determination of Opipramol in Pharmaceutical Preparations and Biological Fluids

Abstract

The electrooxidative behavior and determination of opipramol, a tricyclic compound for therapy of anxious-depressive states and general anxiety disorder, were investigated at a glassy carbon electrode using cyclic, linear sweep, differential pulse and Osteryoung square wave voltammetric techniques. The oxidation of opipramol was irreversible and exhibited a diffusion controlled process dependent on pH using a glassy carbon electrode. The oxidation mechanism on a glassy carbon electrode is proposed and discussed. The anodic process can be attributed to the oxidation of azepine and piperazine rings. Different parameters were tested to optimize the conditions for the determination of opipramol. The dependence of current intensities and potentials on pH, concentration, scan rate, and nature of the buffer was investigated as detailed. Opipramol in pH 3.7 acetate buffer presents a well-defined anodic response at + 0.86 V according to studies of the proposed method. The determination of opipramol was in pH 3.7 acetate buffer, which allowed quantitation over the 2 × 10⁻⁶ to 2 × 10⁻⁴ M range in the supporting electrolyte, 2 × 10⁻⁶ to 6 × 10⁻⁵ M range in the spiked serum sample, and 2 × 10⁻⁶ to 1 × 10⁻⁴ M range in the urine sample, for both techniques. The proposed method was applied to commercial drageés and average percente recovery was in agreement with that obtained by spectrophotometric comparison methods. The method was extended to the in vitro determination of opipramol in spiked human serum and urine.

Keywords:

• Determination
• drageés
• opipramol
• serum
• urine
• voltammetry

This research was supported by a Grant from Ankara University Scientific Research Project Foundation (Grant no: 20030803043) for Dr. Bengi Uslu. The authors would like to thank Novartis Pharma (Istanbul, Turkey) for providing standard opipramol dihydrochloride for developing the proposed methods.

Notes

^a,b Unit of voltammetric methods and UV-spectrophotometric method, respectively.

^a Each value is the mean of five experiments.

^b The figures in parenthesis are the tabulated values of t and F at 95% confidence level.