Microfluidic Radiosynthesis of the Muscarinic M-2 Imaging Agent [F-18]FP-TZTP

3-(4-(3-[F-18]Fluoropropylthio)-1,2,5-thiadiazol-3-yl)-1-methyl-1,2,5,6-tetrahydropyridine ([F-18]FP-TZTP) is a selective F-18-radiotracer for the muscarinic acetylcholine receptor subtype M-2, which can be used to perform positron emission tomography (PET) scans on patients with neurological disorders such as Alzheimer's disease. [F-18]FP-TZTP was produced using continuous-flow microfluidics, a technique that uses reduced amounts of chemical reagents, shorter reaction times and in general, results in higher radiochemical yields compared to currently used techniques. The optimal F-18-radiolabelling conditions consisted of a total flow rate of 40 mu L min(-1) and 190 degrees C, which produced [F-18]FP-TZTP in 26 +/- 10% radiochemical yield with a molar activity of 182 +/- 65 GBq mu mol(-1) and > 99% radiochemical purity.