Table 2.

A few examples of the estimated fractions of drug transported by P-gp or BCRP across the placenta

Compound	Species	Transporter	Ft	Reference
Glyburide	Human	BCRP	0.43	[91]
D-luciferin	Mouse	Bcrp	0.67	[137]
Digoxin	Mouse	P-gp	0.58	[56]
Saquinavir	Mouse	P-gp	0.86	[56]
Paclitaxel	Mouse	P-gp	0.94	[56]
L-652,280	Mouse	P-gp	0.87	[57]
Lopinavir	Mouse	P-gp	0.5	[51]
Norbuprenorphine	Mouse	P-gp	0	[61]
Nitrofurantoin	Mouse	Bcrp	0.75	[95]
Glyburide	Mouse	Bcrp	0.50	[96]
Cyclosporine	Rat	P-gp	0.41	[138]
Tenofovir	Rat	Bcrp	0.33	[92]

F_t values of drugs in mice were estimated using Equation 3 with data in P-gp or Bcrp KO and WT mice. F_t values of drugs in humans or rats were estimated using Equation 4 with placental perfusion data in the presence and absence of an inhibitor. In all the calculations, total plasma or perfusate concentrations or AUCs were used, assuming that that the plasma protein binding of drugs remains the same across the placental barrier.