Voltammetric Determination of Dicyclomine Hydrochloride by Carbon Paste Electrode Modified with Iron (III) Oxide Nanoparticles and Activated Glassy Carbon Electrode in Pharmaceutical Dosage Form, Human Plasma and Urine

A carbon paste electrode modified with iron (III) oxide nanoparticles (MCPE) and an activated glassy carbon electrode (GCE) were constructed for quantitative voltammetric determination of dicyclomine hydrochloride (DH). The voltammetric response of DH was compared at both constructed electrodes. The electrochemical oxidation of the drug was established using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV). For analytical purposes, a well-resolved irreversible diffusive controlled voltammetric peak was obtained at approximately 833 mV using Britton-Robinson (B-R) buffer solution of pH 8.00 using GCE. However, in the case of MCPE, a well-resolved irreversible adsorptive controlled voltammetric peak was obtained at approximately 821 mV at pH 6.00 using the same buffer. A linear relationship was attained between the peak current and DH concentration in the concentration range at 0.92-6.18 μg/mL and 0.13 ×10-6-1.93 ×10-6 μg/mL using GCE and MCPE, respectively. DPV and SWV techniques were developed for the quantitative voltammetric determination of DH in its pure form, in its pharmaceutical dosage form and in biological fluids. The method showed a minimum detectability (LOD) of 0.19 μg/mL and 0.39 ×10-6 μg/mL and a limit of quantitation (LOQ) of 0.59 μg/mL and 1.20 ×10-6 μg/mL with both GCE and MCPE, respectively. The proposed method was validated and compared with the reference method. It revealed good accuracy, precision and reproducible results.