Hydrophobicity for a drug describes its affinity for a non-aqueous environment as opposed to an aqueous environment. The hydrophobicity of a molecule is generated by the disruption of highly dynamic hydrogen bonds between the water molecules. Hence, hydrophobic molecules cannot accept or donate hydrogen bonds with water.2

The hydrophobicity of a protein is measured by residue hydrophobicity scales, also named Wimbley-White scales, in which each amino acid is given a specific absolute value based on peptide bonds and side chains; and each polypeptide is given a value for the transfer of free energies.1


  1. Wimley WC, White SH: Experimentally determined hydrophobicity scale for proteins at membrane interfaces. Nat Struct Biol. 1996 Oct;3(10):842-8. [Article]
  2. Kaliszan R. (2015). Reference module in chemistry, molecular sciences and chemical engineering. Elsevier.