Physiologically Based Pharmacokinetic Model (PBPK)

A physiologically based pharmacokinetic model (PBPK) is a series of compartments (representing organ or tissue spaces) in which body regions of pharmacology or toxicology effect of interest are included based on pharmacodynamic, pharmacokinetic, and physiochemical properties of the drug. The anatomical (organ and tissue volume), physiological (blood flow and enzyme reaction parameters), drug-protein binding, membrane permeability etc. information is required by the PBPK model. The PBPK models are based on perfusion-limited (blood flow rate-limited) transport or membrane transport depending on the physical-chemical properties of drugs.

For the PBPK modeling differential mass balance equations are written for each compartment to describe inflow, outflow, accumulation, and disappearance of drug, and are solved simultaneously.