Development of a novel voltammetric method for revefenacin determination using modified electrodes in pharmaceutical and biological matrices

Revefenacin (REV) is an inhalation solution used for management of Chronic Obstructive Pulmonary Disease (COPD) in the USA, this is single medication that is an approved bronchodilator delivered by nebulization with a once-daily frequency. Even though the crucial necessity of quality control in pharmaceutical manufacturing, no officially recognized methods exist for REV determination in biological samples. A sensitive, economical, simple and efficient electrochemical procedure using carbon paste modified with nanostructured zinc oxide electrode (ZnO-NPs/CPE) was designed for remarkably trace analysis of REV. It was demonstrated that the (ZnO-NPs/CPE) electrode in the Britton-Robinson buffer adjusted to pH 4.0 with the anionic surfactant sodium dodecyl sulfate (SDS), the electrochemical oxidation of REV was significantly enhanced. Under optimal conditions, the REV electrochemical process was irreversible and adsorption-mediated. Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDX) were utilized to characterize the morphology of the modified electrode. Under optimal experimental conditions, the analytical results showed direct relationship responses in the range of 0.19-2.0 µg mL^-1 and a low limit of detection (LOD) of 0.04 µg mL^-1 and limit of quantification (LOQ) of 0.13 µg mL^-1. Our investigation reveals the outstanding applicability of the suggested sensor in quality control laboratories to achieve the fast determination for REV across various sample types (pure form, dosage form, biological samples).