A simple and efficient in vitro method for metabolism studies of radiotracers.

Abstract In vitro metabolism of acetylcholinesterase inhibitors containing 3-[ 18 F]fluoromethylbenzyl- ([ 18 F] 1 ) and 4-[ 18 F]fluorobenzyl-piperidine moieties ([ 18 F] 2 ) was studied and compared with the in vivo metabolism. Defluorination of the [ 18 F] 1 mainly occurred to generate [ 18 F]fluoride ion both in vitro and in vivo. In contrast, the [ 18 F] 2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[ 18 F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers.