Topic
rule of thumb that a compound is likely orally active if it violates at most one of: ≤5 hydrogen bond donors; ≤10 hydrogen bond acceptors; molecular mass of ≤500 Da; octanol-water partition coefficient of ≤5
Lipinski's rule of five, also known as Pfizer's rule of five or simply the rule of five (RO5), is a rule of thumb to evaluate druglikeness or determine if a chemical compound with a certain pharmacological or biological activity has chemical properties and physical properties that would likely make it an orally active drug in humans. The rule was formulated by Christopher A. Lipinski in 1997, based on the observation that most orally administered drugs are relatively small and moderately lipophilic molecules.
