ADME: Is It ‘Druggable’?
“ADME” stands for absorption, distribution, metabolism and excretion. This step, which usually goes alongside optimization, includes standard studies to find out how “druggable” a compound is — that is, can it be turned into a drug that is prescribed by a doctor?
ADME studies show:
- If a compound is stable (will it degrade while sitting in the hospital pharmacy before it gets to the patient?);
- Determine what happens if it does degrade (will it turn into something toxic?);
- Determine where it goes in the body (does it go to the muscle where it is needed, or accumulate in the liver where it is not?)
- Determine what happens to the drug inside the body over time (will it build up until it becomes toxic, or will the patient excrete any excess?).
- If a compound fails ADME studies, a different development candidate may succeed, so a developer may return to optimization. At the end of this stage, the developer has a lead compound that has drug-like properties that can be developed further.
- Depending on the type of therapy being studied, delivery may be very simple or very complex. What method of delivery is feasible depends both on the nature of the therapeutic and on where the drug needs to go in the body to work.