In early drug discovery, we often perform PK testing to determine whether new chemical entities (NCEs) have adequate exposures for in-vivo efficacy models in mice. Even before dosing in the animals, we typically perform in-vitro pharmacokinetic services to filter out compounds with high metabolic rates or weak absorption potential. During preclinical development, pharmacokinetic testing in additional species is generally performed in one rodent and one non-rodent species to prepare for toxicology and toxicokinetics studies. Additional PK services include allometry or other scaling models to predict clinical PK from the preclinical data ahead of the clinical trials. Early clinical PK studies are often performed at sub efficacious dosage with slow dose escalation to maintain safety and determine the clinical PK parameters while ramping towards therapeutic doses. For reformulations or generics of approved compounds, we perform PK testing to demonstrate bioequivalence. During all drug development phases, PK lab test results may be used to assess dose proportionality, steady-state exposure levels, bioavailability, and the general ADME properties of the test compounds in the various test species.