Related Experiment Video
Updated: Nov 17, 2025

A Rapid and Quantitative Fluorimetric Method for Protein-Targeting Small Molecule Drug Screening
Published on: October 16, 2015
Recent advances in the determination of unbound concentration and plasma protein binding of drugs: Analytical methods
Behrouz Seyfinejad1, Sibel A Ozkan2, Abolghasem Jouyban3
1Pharmaceutical Analysis Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
Abstract:
Drugs in the bloodstream are available in both free and bound forms in which the free drug is responsible for pharmacological activities. Since protein binding determines the amount of free concentration of the drug in the blood, determining the protein binding in the early stages of drug discovery and development is of great importance. Besides, it is most beneficial to measure the free concentration of a drug in personalized medicine and therapeutic drug monitoring. For this reason, the need for sensitive, selective, and fast analytical methods to measure the free concentration of drugs and their protein binding has increased. This review aims to summarize recent advancements in analytical approaches used for the determination of free drug concentration and plasma protein binding and will focus on the most important approaches used to determine plasma protein binding. Furthermore, the concepts of each method will be described and discussed, along with their inherent advantages and disadvantages.
Related Concept Videos
Protein-Drug Binding: Determination Methods
Indirect methods involve isolating the bound drug from its free form in biological samples such as blood, serum, or plasma. These techniques aim to measure the percentage of drugs bound to proteins. Equilibrium dialysis is a commonly used method where the free drug concentration at equilibrium is measured by separating the bound...
Drug Distribution: Plasma Protein Binding
Drug Concentrations: Measurements
Plasma...
Physiological Pharmacokinetic Models: Assumption with Protein Binding
Measurement of Bioavailability: Pharmacokinetic Methods
Nonlinear Pharmacokinetics: Bioavailability and Protein-Drug Binding
To quantify the extent of bioavailability, pharmacologists often use a parameter called .

