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

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 D 13‐cis‐RA =7.35×10 −6  cm 2  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.