Electroanalytical and HPLC Methods for the Determination of Oxcarbazepine in Spiked Human Urine and Tablet Dosage Form

In this study, the electrochemical reduction and determination of oxcarbazepine were easily realized in various buffer solutions in the pH range of 4.50 to 11.15 in real samples using glassy carbon electrode (GCE) by cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. The influence of pH on the cathodic peak current and peak potential was investigated. Scan rate studies were also completed. The diffusion controlled nature of the peak was established. The best results for the quantitative determination of oxcarbazepine were obtained by DPV technique in Britton-Robinson (BR) buffer (pH 8.05). In this basic medium, one irreversible and sharp cathodic peak was observed. A linear calibration curve for DPV analysis was constructed in the oxcarbazepine concentration range of 8x10(-6) to 1x10(-4) M. Limit of detection (LOD) and limit of quantification (LOQ) were obtained as 1.65x10(-6) and 5.51x10(-6) M, respectively. Repeatability, reproducibility, precision and accuracy of the developed technique were checked in spiked human urine and tablet dosage forms by recovery studies and results of the high performance liquid chromatography (HPLC) technique. A reduction mechanism for the electrode reaction was proposed.