Eco-friendly analytical methods for the determination of compounds with disparate spectral overlapping: application to antiviral formulation of sofosbuvir and velpatasvir

Abstract

Green analytical chemistry is one of the newest trends in analytical chemistry nowadays targeting the concept of green laboratory practices on chemists and environment. In this text, green practices are proposed in this work for the determination of sofosbuvir (SF) and velpatasvir (VP) in their pharmaceutical formulation. The analysis of SF in a binary mixture with VP represents an analytical challenge due to the complete overlapping of the UV spectrum of SF by that of VP. Therefore, the direct absorbance and derivative measurements cannot resolve such interference and failed to determine SF. In this paper, three direct and simple methods were developed for the analysis of SF without any interference from VP without sample pre-treatment. The proposed methods include measuring the second derivative amplitude of the ratio spectrum of the mixture using VP as a divisor, measuring the absorbance difference of the mixture in NaOH solution against its HCl solution, and using the derivative compensation technique. On the other hand, VP was determined specifically in presence of SF by two methods. Firstly, by its reaction with 4-chloro-7-nitrobenzofurazan (NBD-Cl) where the reaction product was measured spectrophotometrically and spectrofluorometrically and secondly through the reaction of VP with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH). The calibration curves showed good correlation coefficient (r2 > 0.999). The developed methods were highly precise with RSD% values less than 2%. The method greenness profile was compared with other published methods by applying the eco-scale protocol. Assessment results proved that our analytical procedure is greener than other reported methods. Moreover, upon comparison with other methods, the proposed methods showed better or comparable sensitivity in addition to being inexpensive and ecofriendly. Accordingly, these methods could be readily applied for quality control purposes as an eco-friendly, simple and efficient analytical tool.

Facile spectrofluorimetric quantitation of octreotide, a synthetic peptide, in its pure form and pharmaceutical formulation; evaluation of the method’s greenness

“…[ 22 ] Owing to the minimal solvent consumption and minimal instrumental dangers, spectrofluorimetry is one of these green analytical methods. [ 23 ] The present approach is based on direct measurement of the native fluorescence of octreotide acetate solution at 342 nm after excitation at 218 nm (Figure 2). Utilizing distilled water as a diluent, introduces an eco‐friendly quick method for the quantitation of octreotide acetate in its dosage form and authentic form.…”

Analytical and Biological Evaluation of Chromium Complex with Organic Detector NTADBrP: Stability, Calibration, and Inhibition Studies

“…The best absorption value of the chromium complex was within the temperature range of 10-30, where it reached its peak and gave the best color intensity. At higher temperatures, the absorbance decreased, possibly due to a decrease in stability or dissociation of the complex at high temperatures [31][32][33] as shown in Figure 7.…”