A Green, Validated and Stability Indicating UV Spectrophotometric Determination and HPLC Comparison of Covid-19 Drug Favipiravir in Tablets

Favipiravir (FAV) is an antiviral drug in tablets, which has been originally intended for the treatment of influenza and determined by methods based mostly on liquid chromatography. Recently, FAV has been also tried for the treatment of COVID-19 in many countries, Here we present for the first time in the literature a facile and sensitive stability-indicating UV-spectrophotometric method of determining FAV that is effective on a micromolar scale. This green method was developed in aqueous drug solutions. Acidic, basic, oxidative degradation at room temperature as well as thermal degradation studies at 60°C were performed and fully validated in accordance with ICH guidelines, with 230 and 323 nm detection wavelengths used in linearity studies. The developed method was linear at concentrations between 5.0 – 30.0 μg/mL with correlation coefficient > 0.99. FAV concentrations of 1.20 and 3.70 μg/mL were calculated as LOD and LOQ levels, respectively. Recovery results were found within satisfactory precision values of 99.6 – 100.88