Voltammetric Behavior of Chlorzoxazone and Its Electroanalytical Determination in Pharmaceutical Dosage Form and Urine at Gold Electrode

The voltammetric behavior of chlorzoxazone at gold electrode has been investigated for the first time using cyclic, linear sweep, and square wave voltammetric techniques. The dependence of the current on pH, concentration, and scan rate was investigated to optimize the experimental conditions for the determination of chlorzoxazone. The effect of surfactants was studied. The anodic peak was characterized and process was diffusion controlled. The number of electrons transferred in the oxidation process was calculated, and a plausible oxidation mechanism was proposed. In the range of 5.0 ×10−6 to 1.0 × 10−4 M, the current measured by square wave voltammetry presents a good linear property as a function of the concentration of chlorzoxazone with a detection limit of 0.45 × 10−7 M with good selectivity and sensitivity. The proposed method was successfully applied to chlorzoxazone determination in pharmaceutical samples and for the detection of chlorzoxazone in urine as a real sample. This method can be employed in clinical analysis, quality control, and routine determination of drugs in pharmaceutical formulations.