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

Amira F El-Yazbi,Karim M Abdel-Hay,Hytham M Ahmed,Nourhan E Elashkar,Wael Talaat

doi:10.1186/s40543-021-00257-7

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.

Highlights

Hepatitis C is considered as one of the biggest problems in public health that leads to chronic liver disease (Williams, 2006)
Our results prove that the spectrophotometric methods face the challenge of determining each drug in the presence of the other and not their simultaneous determination at the same time, such methods have the advantage of being greener than various chromatographic methods
The obtained results showed that the divisor concentration is proportional to the second derivative values, so increasing or decreasing the divisor concentration results in a decrease or increase in the second derivative values, in spite that, the maxima and minima remain at the same wavelengths

Summary

Introduction

Hepatitis C is considered as one of the biggest problems in public health that leads to chronic liver disease (Williams, 2006). Direct-acting antiviral agents (DAAs) have been recently used either alone or in combination with each other for the treatment of HCV (Cheung et al, 2016). They offer simpler, shorter, and more efficient interferon-limiting therapies for different HCV genotypes (Cheung et al, 2016; Jakobsen et al, 2017). SF (Fig. 1a) is a prodrug, acts as a nucleotide inhibitor of NS5B polymerase, and administered alone or in a mixture with other drugs (McQuaid et al, 2015), VP (Fig. 1b) is a second-generation inhibitor of NS5A protein which is fundamental for HCV replication (Greig, 2016)

Objectives

Methods

Results

Conclusion