Development and Validation for Simultaneous Estimation of Sofosbuvir and Daclatasvir Dihydrochloride in Pharmaceutical Dosage form by Ratio Derivative and Dual Wavelength Methods

Abstract

Development and validation of new simple, sensitive, accurate and precise spectrophotometric method involving ratio derivative and dual-wavelength method, was done as per ICH Q2 (R1) for simultaneous estimation of Sofosbuvir (SOFO) and daclatasvir dihydrochloride (DACLA) in a combined dosage form. The overlapping in the spectra of both drugs was the reason for the selection of both methods. The absorbance difference (ΔA) value between 235.8 nm and 270.6 nm was selected for the quantitative determination of SOFO, where DACLA gives equal absorbance at the selected wavelength in the dual-wavelength method (Method A). The determination of DACLA is done quantitatively by measuring the difference in absorbance value at 249 nm and 268.6 nm where SOFO gives equal absorbance at a selected wavelength. Ratio spectra method (Method B) was based on dividing the spectra of a mixture with standard spectra of one of the analytes, and the first derivative spectra was recorded with Δλ = 8 nm and scaling factor 1. The amount of SOFO and DACLA was estimated in the binary mixtures by computing the first derivative signal at 247.0 nm and 341.0 nm, respectively. The calibration curve was linear in the concentration range of 10–90 μg/mL for SOFO and 4–20 μg/mL for DACLA for both the methods. The methods were successfully applied for the simultaneous determination of these drugs in combined dosage form with acceptable recoveries.