An environmentally sustainable synchronous spectrofluorimetric method coupled with second derivative signal processing for simultaneous determination of velpatasvir and simeprevir in pharmaceutical and plasma samples.

Velpatasvir and simeprevir are two direct acting antivirals that are often used in combination with sofosbuvir to treat HCV infections. Herein, an environmentally benign spectrofluorimetric method was developed for simultaneous quantification of velpatasvir and simeprevir in pharmaceutical and plasma samples. To address the issue of overlapping fluorescence spectra presented by these compounds, this method integrates synchronous fluorescence and second-derivative spectroscopy. By employing the second derivative of the synchronous fluorescence spectra measured at Δλ of 140 nm, the accurate determination of velpatasvir at 400 nm and simeprevir at 426 nm was achieved without any interference. Different experimental parameters affecting the synchronous fluorescence of the studied drugs were carefully optimized. The plots of second-derivative amplitudes against concentrations showed linearity in the range of 5-400 ng/mL for velpatasvir and 80-800 ng/mL for simeprevir. The method was very sensitive, with lower detection limits of 1.11 ng/mL and 25.40 ng/mL, and quantification limits of 3.36 ng/mL and 76.96 ng/mL for velpatasvir and simeprevir, respectively.The method was effectively used to determine velpatasvir and simeprevir simultaneously in their pure forms, pharmaceutical dosage forms, and human plasma with no interference. The suggested technique was additionally evaluated for its eco-friendliness through the utilization of the Analytical GREEnness (AGREE) and Green Analytical Procedure Index (GAPI) evaluation metrics, revealing that the method is indeed sustainable.