Table 1.

The model parameters, descriptions, values, and units.

Parameter	Description	Value[reference]	Unit
F	Drug bioavailability	1 [2]	—
Dose	Concentration of orally delivered drug	0.5 [2]	μmol
V d	Distribution volume	0.2 [2]	L
K a	Absorption rate constant	2 × 10−4 [2]	s −1
K e	Elimination rate constant	5 × 10−5 [2]	s −1
r	Brain capillary radius	2.5 × 10−6 [28]	m
l cap	Inter-capillary distance	5 × 10−5 [29]	m
v blood	Brain capillary blood flow rate	(0.5 − 50) × 10−6 [29]	ms−1
T m−in	Maximum active influx rate	0.1 × 10−12 [assumed]	μmols−1
T m−out	Maximum active efflux rate	0.1 × 10−12 [assumed]	μmols−1
K m−in	Concentration required to attain half of Tm−in	1 × 102 [2]	μmolL−1
K m−out	Concentration required to attain half of Tm−in	1 × 102 [2]	μmolL−1
D ∗	Effective diffusion coefficient	2.5 × 10−16 [20]	m2s−1
V ECF	Brain ECF bulk flow velocity	0.5 × 10−6 [assumed]	ms−1
SABBB	Surface area of the BBB	0.1 × 10−7 [assumed]	m2
P	BBB permeability	10−10 − 10−5 [2, 8]	ms−1
k 1on	Specific association rate constant	10−4 − 102 [30]	(μmolL−1s)−1
k 2on	Non-specific association rate constant	10−6 − 101 [23]	(μmolL−1s)−1
k 1off	Specific dissociation rate constant	10−6 − 101 [30]	s−1
k 2off	Non-specific dissociation rate constant	10−4 − 103 [23]	s−1
B 1 tot	Total concentration on specific binding sites	5 × 10−2 [23]	μmolL−1
B 2 tot	Total concentration on non-specific binding sites	5 × 101 [23]	μmolL−1