lead drug compounds show pharmacological activity against a biological target and the progressive optimization of the pharmacological properties. Measurements such as potency, selectivity, solubility, permeability, metabolic stability, low Cytochrome P450 (CYP) inhibition and good pharmacokinetic (PK) properties tend to apply across most small-molecule discovery programs, as well as the increasing use of calculations to confine lipophilicity (logP/ cLogP), molecular weight and a growing number of other molecular descriptors.