The Rule of 5 as recommended by Chris Lipinski to predict oral bioactivity for drugs. The rule of 5 indicates that absorption is less likely to occur when there are more than (i) 5 hydrogen-bond donors, (ii) 10 (5 × 2) hydrogen-bond acceptors, (iii) a molecular weight greater than 500 (5 × 100), and (iv) a calculated Log P (cLogP) greater than 5.
