Lipinski's

From DrugPedia: A Wikipedia for Drug discovery

Lipinski's “rule-of-five” is a rule-of-thumb that encodes a simple profile for orally bioavailable compounds, basing the classification on a limit on molecular weight, lipophilicity (in terms of the partition coefficient, logP), and hydrophilicity (in terms of counts of hydrogen bond donors and acceptors). These properties can be calculated quickly and can be easily applied to filtering a large database. Likewise, filters can be applied on specific chemical substructures, e.g., those associated with problems in chemical stability or toxicity.