Development of Favipiravir Secondary Standard from Favipiravir Tablets

Abstract

The aim of this study is to develop a secondary standard of favipiravir from favipiravir tablets for a replacement of costly reference standard. Firstly, favipiravir was isolated and purified from the powdered tablets by liquid-liquid extraction method using ethyl acetate and water. The total amount of extracted favipiravir yield 31.25% and the extract was consequently identified using Fourier-transform infrared (FT-IR) spectroscopy. Secondly, quantity or purity of extracted favipiravir was determined using a validated ultraviolet (UV)-visible spectrophotometric method. The analysis result showed that the purity of favipiravir was 95.98% (as is) which the acceptance criteria has been limited within 98.0-102.0%. Unfortunately, although the purity of developed favipiravir secondary standard was nearly met the criteria, it could be preliminary used as a standard substance in some routine pharmaceutical laboratory procedures, such as identification, in-process quality control, including pharmacological studies.