. 2020 Jun;373(3):488–501. doi: 10.1124/jpet.120.264994

TABLE 1.

Physicochemical and pharmacokinetic parameters of methamphetamine and amphetamine used in the full-body parent-metabolite PBPK model with the integrated mechanistic kidney model and peripheral arm vein sampling site

Parameter	Methamphetamine	Amphetamine
Physicochemical
Molecular weight (g/mol)	149.23^a	135.21^a
Compound type	Base^a	Base^a
pK_a	10.21^a	10.01^a
LogP	2.23^a	1.85^a
f_u,p	0.77^b	0.82^b
B/P	1.04^b	1.04^b
MDCK cellular permeability (10⁻⁶ cm/s)	29.1^b	26.9^b
Absorption
k_a (h⁻¹)	5^c	5^c
F_a	1^c	1^c
F_g	1^c	1^c
Distribution
K_p,adipose	3^d	2^d
K_p,bone	3^d	2^d
K_p,brain	9.67^e	9.67^e
K_{p,gastrointestinal tract}	25.2^e	25.2^e
K_p,heart	5.21^e	5.21^e
K_p,kidney	14.5^e	14.5^e
K_p,liver	25^e	25^e
K_p,lung	6.94^e	6.94^e
K_p,muscle	3^d	2^d
K_p,pancreas	12.7^e	12.7^e
K_p,skin	3^d	2^d
K_p,spleen	11^e	11^e
Metabolism (l/h)
CL_total	18.0^f (i.v.)	15.8^g (p.o.)
CL_h	9.91^h	7.41^h
CL_intrinsic	14.4^h	9.87^h
CL_f	—	3.29ⁱ
Excretion (l/h)
CL_r	8.09^f	7.14^j
CL_secretion	48^k (16 × 3)	30^k (10 × 3)

B/P, blood-to-plasma ratio; CL_f, formation clearance; CL_h, hepatic clearance; CL_intrinsic, metabolic intrinsic clearance; CL_r, renal clearance; CL_secretion, renal active secretion clearance at proximal tubule (clearance value of each proximal subsegment S1, S2, and S3); CL_total, total body clearance (intravenous administration for methamphetamine; oral administration for amphetamine); F_a, fraction absorbed; F_g, fraction passed the enterocyte; k_a, absorption rate constant from gut lumen to blood.