Isotretinoin Oxidation and Electroanalysis in a Pharmaceutical Drug Using a Boron-doped Diamond Electrode

Abstract

Isotretinoin redox behaviour, by voltammetry, at the cathodic pre-treated boron doped diamond electrode by cyclic, differential pulse and square wave voltammetry, and by spectrophotometry in a wide pH range, was investigated. The isotretinoin oxidation was an irreversible, diffusion-controlled process, occurred in a three-step cascade mechanism, and the isotretinoin diffusion coefficient D13-cis-RA=7.35×10−6 cm2 s−1, was calculated. The UV-Vis isotretinoin maximum absorption was pH-dependent. The detection limits LOD=0.53 μM, by differential pulse voltammetry, and LOD=0.38 μM, by UV-Vis spectroscopy, were obtained. The isotretinoin in the pharmaceutical drug Roacutan®, using differential pulse voltammetry, was determined.