Absorption Distribution Metabolism Excretion (ADME)

Preclinical ADME (stands for Absorption, Distribution, Metabolism, and Excretion) is part of the drug development process in which weak drug candidates are eliminated, most often done on in vitro samples. This is the process where we investigate the chemical impact on the health of the patient when the drug is ingested. This process will look a little different depending on if you are using small molecules or biologics to develop new drugs.

Biologics

When an antibody dies, we look to measure its half life and the different building blocks that it will disintegrate to.

Small Molecule

Within the human body, a drug candidate will be evaluated on how it is absorbed, distributed, metabolized, and eliminated. Different small molecules will behave differently because of the way they are metabolized, for instance.

Absorption - There are four main routes of exposure:

Inhalation
Absorption through the skin or eye
Ingestion
Injection

Distribution - As the compound moves throughout the body, there are four main ways molecules can move:

Passive diffusion
Filtration
Endocytosis
Special transport - aided by a carrier molecule

Metabolism - the process by which the body will break down the drug candidate. These can influence the toxicity of the drug in a number of ways. These reactions help to identify Adverse Outcome Pathways.

Excretion - Finally, molecules can leave the body in a number of ways. These considerations become very important in determining adverse health effects.

Most excretion occurs through the kidneys as urine or as feces
Some molecules, largely dependent upon size and charge, can be excreted through the skin as sweat
Very few can be excreted via gas from the lungs
Lipid-soluble compounds can accumulate in fat