Fig. 4From: Utility of sustainable ratio derivative spectrophotometry for the concurrent assay of synergistic repurposed drugs for COVID-19 infections; Insilico pharmacokinetics proofFourier convoluted second-derivative spectra of different concentrations of FVM (5, 10, 20 μg/mL) and IVM (2.5, 10, 15 μg/mL) showing zero crossing of FVM at 240 nmBack to article page