Electroreduction of tacrolimus as immunosuppressant agent at hanging mercury drop electrode: application to determination in pharmaceutical formulation

The adsorptive behavior of the immunosuppressive agent tacrolimus was studied by cyclic and differential-pulse voltammetry on a hanging mercury drop electrode (HMDE). The drug was accumulated at HMDE and two well-defined peak currents were obtained at -1353 and -1417 mV vs. SCE (saturated KCl) in borate buffer (pH 10.0) + 0.1 KCl solution. A voltammetric procedure was developed for the determination of tacrolimus using differential-pulse adsorptive stripping voltammetry (DPAdSV). The optimum working conditions for determination of the drug were established. The analysis of tacrolimus in pharmaceutical dosage forms was carried out satisfactorily.