Novel Oxidative Dye Bleaching Method for Quantitative Detection of Remdesivir

A simple, fast, and accurate indirect spectroscopic method has been developed to determine remdesivir (Rem) by the dye bleaching method in an aqueous medium. This method for determining remdesivir involves proposed two steps. First, metanil yellow dye is bleached in acidic media using KBr and KBrO3, which breaks the azo group and reduces it to primary amine groups, turning the dye from yellow-orange to colorless. Second, remdesivir is added to the colorless solution, a reaction likely occurs between remdesivir and any remaining bromine or other oxidation products. The purple color could be due to the formation of a complex between remdesivir and an intermediate oxidation product. Then, the remaining-colored dye (purple) absorption is measured at a wavelength of 526 nm following Beer’s law limitation 2–28 µg.mL− 1. The product remains stable for 60 min, with detection and quantification limits (LOQ) of 0.0181 and 0.0549 µg.mL− 1, respectively. The molar absorption coefficient is 51340.668 and 3325.076 L mol− 1.cm− 1 while the Sandell sensitivity is 0.0117 and 0.1316 µg.cm− 2. The method was successfully applied to estimate the pharmaceutical preparation COVIFOR™ (Injection 100 mg). The relative deviation value was not more than 0.6182%, and the recall rate was 99.4610%, indicating the proposed method’s success in estimating remdesivir and the possibility of its practical use in estimating the drug in pharmaceutical preparations.