Electroanalytical characteristics of amisulpride and voltammetric determination of the drug in pharmaceuticals and biological media

The electrochemical oxidation of antipsychotic drug amisulpride (AMS) has been studied in pH range 1.8 - 11.0 at a stationary glassy carbon electrode by cyclic, differential pulse and square-wave voltammetry. Two oxidation processes were produced in different supporting electrolyte media. Both of the oxidation processes were irreversible and exhibited diffusion controlled. For analytical purposes, very resolved voltammetric peaks were obtained using differential pulse and square-wave modes. The linear response was obtained in the range of 4 x 10(-6) to 6 x 10(-4) M for the first and second oxidation steps in Britton-Robinson buffer at pH 7.0 and pH 3.0 (20% methanol v/v), respectively, using both techniques. These methods were used for the determination of AMS in tablets. The first oxidation process was chosen as indicative of the analysis of AMS in biological media. The methods were successfully applied to spiked human serum, urine and simulated gastric fluid samples.