New Simple Spectrophotometric Method for Simultaneous Determination of Binary Mixture of Sofusbuvir and Velpatasivir in Bulk and Dosage Form

J R. Tulasi¹*_, A. Pani Kumar Anumolu²_, A. Prameela Rani^3
1Department of Pharmaceutical chemistry, faculty of pharmacy, Sir CR Reddy college of pharmaceutical sciences Shanthinagar, GNT road, AP 534007.
²Department of Pharmaceutical analysis, faculty of pharmacy, Gokaraju Rangaraju College of pharmacy. Survey no.288, Nizampet, Bachupallyroad, bachupally, Hyderabad.500090.
³Department of Pharmaceutics, Principal and Professor of university College of Pharmaceutical sciences, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur, A.P.522510.

A B S T R A C T
Two simple accurate reproducible and non-sophisticated Spectrophotometric methods were developed and validated for simultaneous determination of sofusbuvir and velpatasivir without prior separation. The first method was based on employing simultaneous equation method for analysis of both drugs. sofusbuvir and velpatasivir have shown absorbance maxima at 260 and 296 nm in methanol, respectively. Method (II) involves the formation of Q-absorbance equation using the respective absorptivity values at 271nm (isoabsorptive point) and 296 nm (ʎmax of VEL).The drugs obey Beer’s Lambert’s law in the concentration range of 1–60µg/mL for both SOF and VEL (for Method I) and in the range of 1–60 and 2–60 µg/mL for SOF and VEL, respectively (for Method II). The accuracy and precision were determined and recovery studies confirmed the accuracy of the developed methods that were carried out following the International Conference on Harmonization (ICH) guidelines. Statistical comparison of the suggested methods with the reported spectrophotometric one using F and t tests showed no significant difference regarding both accuracy and precision.
Keywords: Simultaneous equation method, Binary mixture, Q-absorbance method, Velpatasvir, Sofosbuvir, Isosbiestic point.