Electrochemical Behaviour of Trimebutine at Activated Glassy Carbon Electrode and its Direct Determination in Urine and Pharmaceutics by Square Wave and Differential Pulse

Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV) were used to explore the electrochemical behaviour of trimebutine (TB) at an activated glassy carbon electrode (GCE). Cyclic voltammetric studies showed a well defined oxidation wave at Britton-Robinson buffer (pH 5.0). The oxidation was reversible and exhibited diffusion controlled process depending on the pH. The mechanism of the oxidation process was discussed. A simple, precise, inexpensive and sensitive voltammetric method has been developed for the determination of the cited drug (TB). According to the linear relation between the peak current and the concentration, DPV and SWV methods were used for the quantitative determination of the cited drug in pharmaceutical dosage forms and urine samples. These two voltammetric techniques allow quantitation of TB over the concentration range from 1.0×10-6 to 1.1×10-5 and1.0×10-6 to 1.9×10-5 mol L-1, respectively, using DPV and SWV methods. The correlation coefficients (r) were 0.998 and 0.999 for DPV and SWV methods, respectively. The linear response was obtained in Britton-Robinson buffer in the range of 1.0 × 10-6-2.0 × 10-5mol L-1 for spiked urine samples. The limit of detection (LOD) and limit of quantification (LOQ) were 1.29×10-8 and 4.29x10-9 for DPV method and 2.34×10-9 and 7.79×10-9 for SWV method. The RSD for five measurements were 0.049 and 0.089 % using 200 mvs-