Pharmacokinetics
How the body absorbs, distributes, metabolises, and eliminates a compound — "what the body does to the drug."
Pharmacokinetics (PK) describes the time course of a compound's concentration in the body, summarised by ADME: absorption (how it gets in), distribution (where it goes), metabolism (how it's broken down), excretion (how it leaves). Key PK parameters include half-life (time for plasma concentration to halve), Cmax (peak concentration), Tmax (time to peak), and AUC (total exposure). For peptides, PK is dominated by enzymatic degradation — most natural peptides have minute-scale half-lives, which is why research peptide engineering focuses on increasing stability.
- GlossaryHalf-life
The time required for plasma concentration of a compound to fall to half its initial value.
- GlossaryPhase 3
The penultimate stage of clinical drug development — large randomised trials testing efficacy and safety against existing standards of care.
- GlossaryPharmacodynamics
"What the drug does to the body" — the relationship between concentration and effect.