Note on drug absorption
They mostly use the computer to find the relative pattern between chemical features and physico-chemical properties. For example, Using atom-based calculation -- > partition coefficient (log P) which tells you the cell permeability -- this is an important feature for drug development, especially for orally administered drugs. Absorption is affected by solubility and permeability. Lipophilicity -- a ratio of octanol solubility to aqueous solubility High-throughput screening started in 1989. The reason why they came up with the rule of 5 -- To reduce the failure rate during phase I development which concerns the safety To reduce poor solubility and permeability MW < 500 kDa LogP < 5 HbondDonor < 5 HbondAccept >10 If two parameters are out of range -- likely to be poor absorption and permeability Ref: Prediction of Physicochemical Parameters by Atomic Contributions (doi: 10.1021/ci990307l ) Experimental and computational approaches to estimate solubility and permeability