Square wave-adsorptive stripping voltammetric technique development and validation for the determination of budesonide in pharmaceuticals and biological fluids using graphite working electrode

Abstract

The cyclic voltammetry method was preliminarily used to study the reversibility nature of the electrochemical behaviour of budesonide (BDN) compound. The square wave-adsorptive stripping voltammetry (SW-AdSV) technique was applied to evaluate an electrochemical reduction of BDN in the phosphate buffer pH 2.5. The ultra-trace graphite working electrode was used to accumulate BDN onto its surface. An SW-AdSV reduction peak was observed in the potential of −0.98 V using Ag/AgCl reference electrode and Pt auxiliary electrode. Different parameters ,such as pH, buffer solutions, accumulations time and potential, frequency, amplitude and scan were investigated, and convection rates parameters were studied to acquire a high reduction response. The repeatability, stability, recovery, calibration curve and limit of detection and quantification parameters were studied to evaluate the analytical performance of the SW-AdSV technique. Repeatability and stability were monitored for 20 µM of BDN to give a 0.29% relative standard deviation (RSD%) that was achieved for five measurements and a very stable current for 120 min. The linearity was evaluated by studying the calibration curve over the range of 2 –25 µM (n = 8), given a linear relation between BDN concentrations and SW-AdSV signals. The limits of detection (LOD) and quantification (LOQ) were calculated to become 40 nM (0.017 ppm) and 0.134 µM (0.0577 ppm), respectively. The developed and validated method was successfully applied to the electrochemical study of BDN in pharmaceuticals and biological fluids.