Pharmacodynamics (PD) refers to the action of a drug to the body, involving receptor binding, post-receptor effects, and chemical interactions. Pharmacokinetics (PK) determines the onset, duration, and intensity of drug action. Successful drug discovery relies on the selection of drug candidates with good in vivo PK properties, as well as appropriate preclinical efficacy and safety. In vivo PK profiling is often a bottleneck in the discovery process.
In order to prove effective, a drug delivered to the patient must reach the necessary concentration in the plasma and in relevant tissues (as measured by PK). This is necessary to effectively modulate the activity of the target protein (as measured by PD) in the body. Incorporating in vivo PK/PD efficacy studies at the early stages of drug development program can significantly accelerate the selection of the most promising compounds.
