A Green Eco-friendly Analytical Method Development, Validation, and Stress Degradation Studies of Favipiravir in Bulk and Different Tablet Dosages Form by UV-spectrophotometric and RP-HPLC Methods with their Comparison by Using ANOVA and in-vitro Dissolution Studies

Abstract

Favipiravir is an antiviral drug with significant and widespread antiviral action. Favipiravir was crucial in the contest against the COVID-19 pandemic because of how well it treated the SARS-CoV-2 virus. It is well known that contemporary pharmaceutical analysis establishes green, stability-indicating analytical procedures. The current study aimed to develop and assess UV-spectrophotometric (zero order, first order, area under the curve) and RP-HPLC methods for estimating favipiravir in its pharmaceutical dose form, comparing them using ANOVA and an in-vitro dissolution analysis. A green solvents composition of methanol, ethanol, and water (25:35:40 v/v/v) is used for analysis as a mobile phase and diluent. Method A is a simple zero-order spectrophotometric method for determining favipiravir at 236 nm, and the correlation coefficient in the linearity study was found to be 0.9962, LOD, and LOQ are 0.18 and 0.55 μg/mL. Method B is a first-order spectrophotometric method for determining favipiravir at 227 nm, and the correlation coefficient in the linearity study was found to be 0.9964, LOD, and LOQ are 0.64 and 1.96 μg/mL. Method C is an area under the curve spectrophotometric method for determining favipiravir at 230 to 243 nm, and the correlation coefficient in the linearity study was found to be 0.9986, LOD, and LOQ are 0.32 and 0.96 μg/mL. Method D is the RP-HPLC method for the determination of favipiravir at the retention time of 7.216 min, a flow rate of 0.80 mL/min, column temperature of 25°C, at 236 nm, Isocratic mode, and the correlation coefficient in the linearity study was found to be 0.9996, LOD, and LOQ are 0.52 and 1.56 μg/mL. All developed methods demonstrated good repeatability and recovery with %RSD < 2. The proposed established methods were assessed using one-way ANOVA. It was revealed that the Fcalculated value was lower than the Ftabulated value, with no discernible variation in the assay results. Studies on stress degradation show that oxidation and acid degradation mostly impact favipiravir solutions. The Analytical Eco-scale verified that these methods are the greenest and most environmentally friendly, enabling the suggested approach to use an effective green analytical methodology to measure favipiravir extensively. Phosphate buffer (pH 6.4) was the best dissolution medium after analysis of the favipiravir dissolution study in several dissolution media.