Fluorine atoms have a unique combination of electronic and physical properties. As such, when incorporated into APIs, fluorine atoms often influence their protein binding affinity and lipophilicity. Fluorination can thus significantly impact the bioavailability of drug substances. “Fluorination is a key reaction in organic synthesis, as evidenced by the fact that between 15% to 20% of all medicines and agrochemicals on the market contain at least one fluorine atom in their structure, where fluorine is used to modify properties of the drugs like lipophilicity and bioavailability or metabolic stability,” states Rafael Antunes, director of API portfolio development with Hovione.