Favipiravir and its Impurities
Favipiravir is a modified pyrazine analog that was initially approved for therapeutic use in resistant cases of influenza.The antiviral targets RNA-dependent RNA polymerase (RdRp) enzymes, which are necessary for the transcription and replication of viral genomes.Not only does favipiravir inhibit replication of influenza A and B, but the drug has shown promise in the treatment of avian influenza, and may be an alternative option for influenza strains that are resistant to neuramidase inhibitors.Favipiravir has been investigated for the treatment of life-threatening pathogens such as Ebola virus, Lassa virus, and now COVID-19. Reference standards of Favipiravir API,and its pharmacopeial, non pharmacopieal impurities, and stable isotopes are listed below.
