Osteryoung Square Wave Voltammetric Determination of Phenazopyridine Hydrochloride in Human Urine and Tablet Dosage Forms Based on Electrochemical Reduction at Carbon Paste Electrode

An electroanalytical method was developed for the direct quantitative determination of phenazopyridine hydrochloride (PAP) or in other words, pyridium, in spiked human urine and tablet dosage forms. The electrochemical reduction and determination of PAP were carried out at carbon paste electrode (CPE) in various aquaeous solution in the pH range of 0.5-12.30 by (CV) and osteryoung square wave voltammetry (OSWV). The best results were obtained for the quantitative determination of PAP by OSWV method in 0.5 mol L-1 sulfuric acid at about pH 0.51. The peak current and peak potential depend on pH and scan rate were studied. The diffusion controlled nature of the peak was established. This electroanalytical procedure made it possible to determine PAP in the concentration range 2.5x10-8-2.5x10-6 mol L-1. Limit of detection (LOD) and limit of quantification (LOQ) were obtained as 7.5x10-9 and 2.5x10-8 mol L-1 respectively. Precision and accuracy of the developed method were checked by recovery studies in spiked urine and tablet dosage forms.