TABLE 3

Comparison of the physicochemical properties and transplacental pharmacokinetic parameters

	Diclofenac	Salicylic	Antipyrine
Class	Acid	Acid	Base
Mol. wt.	296.15	138.12	188.23
pK_a	4.0^a	2.90^b	1.4^c
logD (pH 7.4)	1.13^a	-1.86^d	0.27^d
log{D/(mol. wt.^0.5)}	-0.11	-2.93	-0.87
Estimated permeability (PS)^d	44.1 × 10^-4	5.45 × 10^-4	25.1 × 10^-4
K′₁ (ml/min/g cotyledon)	6.27	0.0451^e	0.0735
k₂ (min^-1)	0.406	0.0238^e	0.0657
K′₁/k₂ (ml/g cotyledon)	15.4	1.89^e	1.12

↵ a Novartis Pharma Co., 2005.
↵ b Hänninen et al., 2003.
↵ c Ghafourian et al., 2004.
↵ d Liu et al., 2004.
↵ e Shintaku et al., 2007.