Fig. 2.
A compartmental blood-brain barrier (BBB) model to describe a concentration-time profile in the central (plasma) and brain compartment after a single intravenous bolus or oral dose. (A) A one-compartment model to describe the total concentration-time profile in plasma and to get systemic parameters for a forcing function. (B) A compartmental BBB model to describe the total concentration-time profile in brain. Cb, concentration in brain; Cp, concentration in plasma; Ka, absorption rate constant; Ke, the elimination rate constant from the central compartment; Kin, tissue transfer rate constant into the brain; Kout, tissue transfer rate constant out of the brain; Vb, the apparent volume of distribution in brain; Vc, the volume of distribution in central compartment.