The importance of striving for and maintaining drug-like physicochemical properties during the hit and
lead optimization process is now well documented, and many published studies have suggested optimal
ranges and/or limits for key molecule descriptors such as size, lipophilicity, H-bonding characteristics,
rotatable bond and aromatic ring counts, particularly with regard to the design of orally administered
drugs. The aim of this article is to review various approaches that have been used to represent molecule
properties graphically in the context of oral ‘drug likeness’, with the goal of improving the decision
making of medicinal chemists during the drug discovery process.