Electroanalytical investigation and voltammetric quantification of antiviral drug favipiravir in the pharmaceutical formulation and urine sample using a glassy carbon electrode in anionic surfactant media

This work describes the electrochemical investigation of a promising antiviral agent, favipiravir (FAV) utilizing a nonmodified glassy carbon (GC) electrode, along with a unique voltammetric approach that can determine FAV with a good degree of accuracy, speed, and cost-effectiveness. Using cyclic voltammetry, the compound demonstrated a single well-defined and an irreversible oxidation peak at approximately +1.12 V (vs. Ag/AgCl) in Britton–Robinson (BR) buffer at pH 10.0. The synergistic effect of anionic surfactant, sodium dodecyl sulfate (SDS) on the adsorption ability of GC electrode remarkably increased the sensitivity of the stripping voltammetric measurements of FAV. Employing square-wave adsorptive stripping voltammetry at +1.17 V (vs. Ag/AgCl) (after 60 s accumulation at open-circuit condition) in BR buffer (pH 10.0) containing 3 × 10(−4) M SDS, the linear relationship is found for FAV quantification in the concentration from 1.0 to 100.0 μg mL(−1) (6.4 × 10(−6)–6.4 × 10(−4) M) with a detection limit of 0.26 μg mL(−1) (1.7 × 10(−6) M). The proposed approach was used successfully to determine FAV in pharmaceutical formulations and model human urine samples.