Table 2. In Vitro Safety Assessment and Plasma Stability of Tested Compounds 14–16 and 21–24.

	Caco-2 cell permeability (50 μM)	rat plasma stability	human plasma stability
compound	Papp (cm/s)	% remaining after 8 h
14	5.7 × 10–6	55	100
15	1.9 × 10–6	99	100
16	1.2 × 10–6	43	94
21	1.0 × 10–4	88	99
22	1.2 × 10–5	57	98
23	3.1 × 10–6	32	100
24	1.3 × 10–6	38	100