Table 2.

Main PK/PD characteristics of the first-generation of SV2A radiotracers derived from IUCB Pharma library. LogP measured from octanol/water partition coefficient at 258C and pH 7.4, Efflux ratio (ER) derived from apparent permeabilities, the intrinsic clearance (Clint) measured in human microsomes, the fraction unbound in rat brain tissue (Fu% brain) and the ratio of free brain concentration versus free plasma concentration (Free B/P ratio).

Tracers	LogD	ER	Clint µL·min−1·mg·Protein−1	Fu% Brain	Free B/P Ratio
[11C]UCB-A	1.4	1.2	20	12	0.6
[18F]UCB-H	2.3	0.7	12	8	1.6
[11C]UCB-J	2.5	0.8	16	4.5	1.6