“…The relationships identified here are unsurprising, being similar to those for permeability of epithelia and biological membranes (e.g., skin, intestine, blood-brain barrier, cornea) where lipophilicity, hydrogen bonding potential, and MW are known to be key determinants. [51,55,57,58] They are also entirely consistent with Lipinski's rules for drug-like small molecules, which emphasizes the requirement for low molecular weight (<500), low numbers of hydrogen bond donors and acceptors (<5 and <10, respectively), and a log P <5 for optimal intestinal absorption, which is a balance between aqueous solubility and membrane permeability. [54] While Eqn 1 provides a potentially useful tool for estimating tumour tissue diffusion coefficients computationally, given that all the required parameter values can be readily calculated for virtual compounds, some cautions need to be sounded.…”