A novel LC-MS/MS method for determination of the potential antiviral candidate favipiravir for the emergency treatment of SARS-CoV-2 virus in human plasma: Application to a bioequivalence study in Egyptian human volunteers

A novel, fast and sensitive LC-MS/MS method was developed and validated for the bioanalysis of the antiviral agent favipiravir (FAV); a promising candidate for treatment of SARS-CoV-2 (COVID-19) in human plasma using pyrazinamide as an internal standard (IS). Simple protein precipitation was adopted for plasma sample preparation using methanol. Chromatographic separation was accomplished on Eclipse plus C-18 column (50 x 4.6 mm, 3.5 mu m) using a mobile phase composed of methanol-0.2 % acetic acid (20:80, v/v) pumped at a flow rate 0.6 mL/min in an isocratic elution mode. The API4500 triple quadrupole tandem mass spectrometer was operated with multiple-reaction monitoring (MRM) in negative electrospray ionization interface for FAV and positive for IS. The MRM function was used for quantification, with the transitions set at m/z156.00 113.00 and m/z124.80 81.00 for FAV and IS. The method was optimized and fully validated in accordance to US-FDA guidelines. Linearity was acquired over a concentration range of 100.0-20000.0 ng/mL by computing using weighted linear regression strategy (1/x(2)). The proposed method was effectively applied for the pharmacokinetic evaluation of FAV and to demonstrate the bioequivalence of a new FAV formulation (test) and reference product in healthy Egyptian human volunteers. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel LC-MS/MS method was developed and validated for the bioanalysis of favipiravir in human plasma, demonstrating bioequivalence of a new formulation of favipiravir compared to the reference product in healthy Egyptian volunteers.