Green Adsorptive Stripping Electrochemical Methods for Determination of Vortioxetine Hydrobromide at Graphite Pencil Electrode

Vortioxetine hydrobromide is a recently developed antidepressant drug which is associated with a great concern of suicide attempts. Herein, eco-friendly, inexpensive and sensitive electrochemical methods were developed to help control vortioxetine hydrobromide (VOR) at clinical safe level. The methods are based on anodic stripping differential Pulse (ASDPV), square wave (ASSWV) and linear sweep (ASLSV) voltammetry utilizing the high adsorption affinity of VOR on a graphite pencil lead. Several experimental parameters affecting the electrochemical oxidation process including pH, supporting electrolyte, scan rate and accumulation time were investigated. Calibration curves exhibited linear responses with detection limits of $2.0\times 10^{-8}$ M for the ASDPV and ASSWV, and $1.4\times 10^{-8}$ for the ASLSW. Evaluation of within-day repeatability and day to day precision using two different concentrations of the drug substance showed satisfactory accuracy and precision. The three methods were used successfully for the assay of VOR in the finished product. Furthermore, the ASSWV method was employed for the selective measurement of VOR in human plasma and urine samples.