Sustainable synchronized spectrofluorimetric determination of remdesivir and baricitinib: a first-derivative synchronous approach with multi-color and GLANCE assessment.

This study presents a novel, rapid, and sensitive spectrofluorometric method for the simultaneous quantification of remdesivir and baricitinib, for the treatment of hospitalized patients with Covid-19 pneumonia. The method utilizes a first-order derivative synchronous spectrofluorimetry technique, with measurements taken at 388 nm for remdesivir and 383 nm for baricitinib, using a wavelength interval (Δλ) of 140 nm. A linear correlation (r = 0.9999) was established between derivative signal amplitudes and concentration across the ranges of 25.0-2000.0 ng /mL for both analytes. The method was validated per ICH guidelines including accuracy and precision. The developed method also successfully quantified the target drugs individually, in laboratory prepared mixtures and laboratory-prepared dosage form, without interference from each other or from excipients. The method enabled the simultaneous analysis of these drugs in spiked human plasma at concentrations relevant to higher therapeutic levels and combination therapy studies, yielding results with acceptable precision (standard deviation ≤ 1.48). The method's environmental sustainability and practical applicability were evaluated to confirm its overall utility for the analysis of these pharmaceuticals.