Umifenovir

Umifenovir, sold under the brand name Arbidol, is an antiviral medication for the treatment of influenza and COVID infections used in Russia and China. The drug is manufactured by Pharmstandard (Russian: Фармстандарт). It is not approved by the U.S. Food and Drug Administration (FDA) for the treatment or prevention of influenza.

Chemically, umifenovir features an indole core, functionalized at all but one positions with different substituents. The molecular groups of umifenovir - hydroxy, amino and carboxy - can interact to form various hydrogen-bonded synthons. Antiviral activity and acceptable cytotoxicity profiles make it a promising candidate for further research as a potential therapeutic agent for the selective treatment of flavivirus infections . Umifenovir is characterized by only one polymorphic form but can exist in the form of a large number of crystal solvates, the production of which depends on the medium and conditions of synthesis. In this case, the implementation of the crystal solvate or other solid form may be determined by the spatial structure and conformational equilibria in the saturated solution . The drug has been shown in studies to inhibit viral entry into target cells and stimulate the immune response.