Protein binding

Cyprotex is a specialist provider of ADME and PK services and provide a range of in vitro protein binding assays.

Plasma protein binding and whole blood binding

Plasma protein binding and red blood cell binding plays an important role in the distribution and pharmacokinetics (PK) of a potential drug. In general, only unbound drug is available for passive diffusion to extravascular or tissue sites where therapeutic effects occur and therefore plasma protein binding is an important determinant of drug efficacy.

As part of our portfolio of ADME/PK services, Cyprotex provide a plasma protein binding service and a whole blood binding service for a wide range of species. For more background information on plasma protein binding studies, see our online ADME guide.

Brain tissue binding

If a link between exposure and CNS efficacy is required then it is important to investigate the binding capacity of the brain tissue in combination with total brain levels and BBB permeability.

Cyprotex provide a brain tissue binding service as well as MDR1-MDCK permeability and brain to plasma ratio services.

Blood to plasma ratio

Parameters determined using plasma data (e.g., pharmacokinetic parameters) may be misleading if concentrations of drug differ between plasma and red blood cells as a consequence of differential binding to a specific component in the blood. The blood to plasma ratio determines the concentration of the drug in whole blood compared to plasma and provides an indication of drug binding to erythrocytes.

Cyprotex offer a blood to plasma ratio service for a wide range of different species.

Microsomal binding

Drug that is sequestered in microsomes in vitro is presumed to be unavailable for direct interaction with metabolizing enzymes, just as drug that is bound to plasma proteins and tissue macromolecules in vivo is presumed to be unable to be directly acted on by drug metabolizing enzymes. Microsomal binding is an important factor in the prediction of in vivo pharmacokinetics from in vitro drug metabolism data and the prediction of drug-drug interactions.

Cyprotex offer a microsomal binding service for a range of different species.