Electrooxidation of cetirizine dihydrochloride with a glassy carbon electrode.

The electrochemical oxidation of cetirizine dihydrochloride (CTZH) at different pHs and concentrations using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) with a glassy carbon (GC) electrode was studied. This study indicated that CTZH was susceptible to oxidation. The statistical analysis proved that the CV and DPV methods were reproducible and selective for the determination of CTZH. The results showed that voltammetric determination of CTZH could be made in the concentration ranges of 2 x 10(-5) M - 1 x 10(-4) M by CV and 2 x 10(-5) M - 1 x 10(-4) M by DPV with a GC electrode. The oxidation process was found to be irreversible over the pH range studied (2-10) and was shown to be mainly diffusion controlled. The determination of CTZH was performed in phosphate buffers covering the pH range of 2-10. No satisfactory results were obtained in 0.5 M H2SO4 solution. With both of the methods used the best results were obtained in phosphate buffer of pH 8. Application of the suggested methods to pharmaceutical formulations is presented and compared with the first derivative spectrophotometric method. No interference was observed from common pharmaceutical adjuvants.