Drug-Protein Binding

Swiss BioQuant employs the following methods to determine unbound drug concentration in plasma, serum, or tissue:

• Equilibrium dialysis
• Ultrafiltration
• Ultracentrifugation

The drug-protein binding can be performed using plasma or tissue sample which is first spiked with the test item at one or more concentrations and then incubated for a prescribed period of time. Alternatively incurred samples from clinical or toxicology studies can be used instead. The unbound concentration is then determined using one of the above mentioned assays followed by LC/MS/MS analysis. Equilibrium dialysis can be performed with the RED device.

Protein binding can also be assessed for individual proteins such as:

• Human serum albumin
• Human α1-acid glycoprotein   
• Human sex hormone binding protein