ADME Properties

Optimization of the ADME (Absorption, Distribution, Metabolism, and Excretion) properties of the drug molecule is often the most difficult and challenging part of the whole drug discovery process. The ADME profile will also have a major impact on the likelihood of success of a drug.

See also the section on Formulation, Solubility

Hints that all is not well with the pharmacokinetic profile of a drug candidate.

Dose proportionality issues, increasing dose does not lead to a corresponding increase in plasma levels :- Absorption issues
Good plasma levels but little in the brain:- Active efflux (PGP substrate).
Plasma levels decrease on repeat dosing:- Enzyme induction.
Plasma levels increase when co-administered with another drug:- Enzyme inhibition.
Duration of action does not match half-life :-Active metabolites.


Absorption Assays that can be used to evaluate absorption properties, interpretation and possible strategies to provide solutions.

Distribution Assays and properties of molecules effecting plasma protein binding.
Brain Penetration Assays and properties of molecules influencing brain penetration
Transporters proteins involved in transporting molecules/ions into and out of cells

Metabolism Assays, interpretation of in vitro data, General Strategies for reducing metabolism.

Excretion (In Progress)

See Also CYP450 Interactions


Updated 6 December 2009
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