RT Journal Article SR Electronic T1 Highly efficient production of [18F]fallypride with low concentration of base JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1502 OP 1502 VO 51 IS supplement 2 A1 Moon, Byung Seok A1 Park, Jun Hyung A1 Lee, Hong Jin A1 Kil, Hee Sup A1 Chi, Dae Yoon A1 Lee, Byung Chul A1 Kim, Yu Kyeong A1 Kim, Sang Eun YR 2010 UL http://jnm.snmjournals.org/content/51/supplement_2/1502.abstract AB 1502 Objectives [18F]Fallypride exhibits an effective radiotracer for the study of dopamine D2/D3 receptor occupancy, neuropsychiatric disorders and aging in humans. However, automated labeling efficiency showed moderate radiochemical yields about 5-40% with relatively long incorporation time of fluorine-18, preceded high temperatures (150-165 °C) or involved the use of an unusual microwave system in automatic devices. In present study, we describe an automated radiochemical synthesis of [18F]fallypride in different base concentration and incorporation time of fluorine-18 for potentially utilizable in routine production sites. Methods To minimization of base concentration of phase-transfer catalyst, [18F]fluoride was extracted with different concentrations of tetrabutylammonium bicarbonate (TBAHCO3) or Kryptofix 2.2.2./K2CO3 in organic solvent such as CH3CN/H2O or MeOH/H2O from 18O-enriched water trapped on the activated ion exchange cartridge (Chromafix® PS-HCO3). After azeotropic drying, the labeling reaction proceeded in CH3CN at 100 °C for 10 or 30 min. The desired product, [18F]fallypride, was purified by reverse phase HPLC and collected solution was exchanged for 10% ethanol in saline using tC18 Sep-Pak for clinical research. Results The radiochemical yield was increased according to decreasing amounts of base concentration. The labeling condition of [18F]fallypride was optimized that 2 mg of tosyl-fallypride in acetonitrile (1 mL) was heated at 100 °C for 10 min with 40% TBAHCO3 (10 μL). [18F]Fallypride was obtained with high radiochemical yield about 68 ± 1.6% (decay-corrected, n = 8) within 51 ± 1.2 min including HPLC purification and solid-phase purification. The specific activity showed about 140-192 GBq/μmol. Conclusions [18F]Fallypride was prepared with a significantly improved radiochemical yield with high specific activity and shorten synthetic time. This automated procedure for [18F]fallypride production could facilitate its routine clinical use in dopamine D2/D3 studies