favipiravir determination in pharmaceutical formulation via hplc chromatographic approach

Favipiravir is a broad-spectrum antiviral drug and it has increasing interest regarding its potential use in covid-19 therapy.  in the present work, a simple, fast, precise reverse-phase high-performance liquid chromatography (rp-hplc) technique was developed for the quantification of favipiravir (fvp) from pharmaceutical formulation. moreover, the spectral and chromatographic behavior of fvp was investigated. the developed method was performed using an ace 5 c18 column (250 mm × 4.6 mm, 5 µm), with the mobile phase composition 10 mm phosphate buffer (ph = 2.5): methanol (80:20, v/v) at a flow rate 0.6 ml/min. the method validation parameters, such as linearity, precision, accuracy, and robustness, were determined. the recovery yields for accuracy were between 99.9 and 101.4 % for three concentrations. the linearity range was determined between 0.5 and 100 µg/ml with a regression coefficient (r2) 0.99998. the limit of detection and limit of quantification values were evaluated as 0.02 µg/ml and 0.05 µg/ml, respectively. the precision of the method was evaluated in inter-day and intra-day precision studies with a relative standard deviation of less than 2%. the method’s robustness was investigated using the alteration of flow rate, detection wavelength, and mobile phase ratio.  moreover, the effect of the ph and mobile phase ratio on the capacity factors was analyzed and the pka value of the fvp was determined chromatographically as 5.03 ± 0.02.