Green and sensitive spectrofluorimetric determination of Remdesivir, an FDA approved SARS-CoV-2 candidate antiviral; application in pharmaceutical dosage forms and spiked human plasma.

Fluorescence spectroscopy has gained much attention over the last few years. Its advantages cover both analytical performance as well as ecological greenness. The quality control of pharmaceuticals requires sensitive, fast and economic methodologies to provide a high throughput at desirable costs. The low energy and decreased solvent consumption make this technique green as well as economic, and hence it is much preferred by pharmaceutical industries. Remdesivir is a recent antiviral, previously used for the treatment of Ebola virus infections, which was approved by the US-FDA in 2020 for treatment of infections caused by SARS-CoV-2 virus. Formulation and wide-scale production of this drug started recently and hence methodologies related to its quality control are highly required. A smart spectrofluorimetric method was validated as per the US-FDA guidelines for the facile estimation of Remdesivir. The assay of Remdesivir was based on its native fluorescence measurements at pH 4 and wavelengths of 244/405 nm. Calibration was achieved over the range of 1.0-65.0 ng mL-1. Different variables affecting the proposed methodology were studied to achieve maximum sensitivity, at limits of detection and quantification of 0.287 and 0.871 ng mL-1, respectively. The developed method is regarded as the first spectrofluorimetric one for the estimation of Remdesivir. The developed method was also utilized for the determination of the drug in its formulated IV infusion and in spiked human plasma. Statistical analysis verified that this method is accurate and reproducible. Moreover, the ecological impact of the developed procedures was evaluated on two recently reported assessment metrics, the Green Analytical Procedure Index (GAPI) and AGREE-analytical greenness metric, to emphasize the greenness of the procedure.