Development of an efficient dispersive liquid-liquid microextraction approach combined with spectrophotometry for determination of antiviral drug, valacyclovir HCl in pharmaceutical formulations

Abstract

ABSTRACT. A new, fast, sensitive, simple, and green dispersive liquid–liquid microextraction (DLLME)-based spectrophotometric method for the determination of valacyclovir HCl (VAL) in pure form and pharmaceutical formulations has been developed and validated. The developed method is based on the formation of a coloured product through the reaction of VAL and 1,2-naphthoquine-4-sulfonate (NQS) at pH  =  9. The important experimental parameters affecting the extraction efficiency were investigated and optimized. The tiny organic droplets had a wavelength of l = 505 nm. At the optimum conditions, linearity ranged from 0.06 to 2.0 μg/mL, with a linear correlation coefficient of 0.9995. The limits of detection and quantification were 0.02, and 0.06 μg/mL, respectively. The enhancement factor was 36.87. Good recovery as accuracy (99.50%) and relative standard deviation (RSD) as precision were 1.20%, respectively. The developed DLLME method was successfully applied to the determination of VAL in pharmaceutical formulations, and the validity was assessed by applying the standard addition technique. The results obtained by the proposed method for the pure VAL and commercial tablets agreed well with those obtained by the official method.   KEY WORDS: Valacyclovir HCl, Spectrophotometry, 1-2-Naphthoquine-4-sulfonate, Dispersive liquid–liquid microextraction, Pharmaceutical formulations   Bull. Chem. Soc. Ethiop. 2023, 37(3), 579-592.                                                     DOI: https://dx.doi.org/10.4314/bcse.v37i3.4