作者:Kenneth Dahl、Armando Garcia、Nickeisha A. Stephenson、Neil Vasdev
DOI:10.1002/jlcr.3751
日期:2019.6.15
There is a great demand to develop more cost-efficient and robust manufacturing processes for fluorine-18 (18F) labelled compounds and radiopharmaceuticals. Herein, we present to our knowledge the first radiofluorination “in-loop,” where [18F]triflyl fluoride was used as the labelling agent. Initial development of the “in-loop” [18F]fluorination method was optimized by reacting [18F]triflyl fluoride with 1,4-dinitrobenzene to form [18F]1-fluoro-4-nitrobenzene. This methodology was then applied for the syntheses of two well-known radiopharmaceuticals, namely, [18F]T807 for imaging of tau protein and [18F]FEPPA for imaging the translocator protein 18 KDa. Both radiotracers were synthesized and formulated using an automated radiosynthesis module with nondecay corrected radiochemical yields of 27% and 29% (relative [18F]F−), respectively. The overall syntheses times for [18F]T807 and [18F]FEPPA were 65 and 55 minutes, respectively. In these cases, our “in-loop” radiofluorination methodology enabled us to obtain equal or superior yields compared with conventional reactions in a vial. The radiochemical purities were more than 99%, and the molar activities were more than 350 GBq/μmol at the end-of-synthesis for both radiotracers. This novel method is simple, efficient, and allows for a reliable production of radiofluorinated compounds and radiopharmaceuticals.
目前对开发更加成本效益高且稳健的氟-18(18F)标记化合物和放射性药物的制造工艺有着巨大需求。本文中,我们首次报道了"内循环"放射性氟化反应,其中使用[18F]三氟磺酸盐作为标记试剂。通过将[18F]三氟磺酸盐与1,4-二硝基苯反应生成[18F]1-氟-4-硝基苯,优化了"内循环"[18F]氟化方法的初步开发。随后,该方法被应用于合成两种著名的放射性药物,即用于tau蛋白成像的[18F]T807和用于18 kDa转运蛋白成像的[18F]FEPPA。两种放射性示踪剂均采用自动化放射合成模块合成并配制,非衰变校正的放射化学产率分别为27%和29%(相对[18F]F−)。[18F]T807和[18F]FEPPA的总合成时间分别为65分钟和55分钟。在这些情况下,我们的"内循环"放射性氟化方法使我们能够获得与传统试管反应相等或更高的产率。两种放射性示踪剂的放射化学纯度均超过99%,摩尔活度在合成结束时均超过350 GBq/μmol。这种方法简单、高效,并且能够可靠地生产放射性氟化化合物和放射性药物。