Wessmann S H, Henriksen G, Wester H-J
Chair of Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany.
Nuklearmedizin. 2012;51(1):1-8. doi: 10.3413/Nukmed-0425-11-08. Epub 2011 Oct 11.
The radiosynthesis of the vast majority of 18F-labeled tracers rely on azeotropic drying of [18F]fluoride and subsequent cryptate mediated introduction of [18F]fluoride by nucleophilic substitution. THE AIM of this study was to develop a method for simplification of this process, based on preparation of reactive [K(+) is a subset of 2.2.2]18F(-) by solvent drying of [18F]fluoride adsorbed onto an anion exchange resin.
Aqueous [18F]fluoride (0.5-1 ml) obtained from the 18O(p,n)18F nuclear reaction was trapped on a strong anion-exchange (SAX) cartridge. After washing the cartridge with dry CH3CN, [18F]fluoride was eluted with an anhydrous solution of [K(+) is a subset of 2.2.2]OH(-) in CH3CN and directly used for nucleophilic fluorination reactions.
[18F]Fluoride from target water was quantitatively retained by the SAX cartridge, and water-free [18F]fluoride recovered in an overall yield of 92±5% (n = 10). [18F]Fluoride obtained by this procedure led to radiochemical yields of 70-90% for [18F]FDG, [18F]FET, [18F]FLT, [18F]FAZA and [18F]Fallypride.
SAX-resin adsorbed [18F]fluoride can be dried with non-aqueous solvents and eluted with [K(+) is a subset of 2.2.2]OH(-) in CH3CN. The reactivity of [K(+) is a subset of 2.2.2]F(-) generated by the new method is comparable to that of [18F]fluoride obtained by azeotropic drying. The described procedure facilitates the automated production of 18F-radiopharmaceuticals in general, and may also simplify the use of microfluidic devices for 18F-radiotracer production.
绝大多数18F标记示踪剂的放射性合成依赖于[18F]氟化物的共沸干燥以及随后通过亲核取代由穴合物介导引入[18F]氟化物。本研究的目的是基于通过干燥吸附在阴离子交换树脂上的[18F]氟化物制备活性[K(+)是2.2.2的子集]18F(-)，开发一种简化该过程的方法。
从18O(p,n)18F核反应获得的水性[18F]氟化物（0.5 - 1 ml）捕集在强阴离子交换（SAX）柱上。用干燥的CH3CN洗涤柱后，[18F]氟化物用[K(+)是2.2.2的子集]OH(-)在CH3CN中的无水溶液洗脱，并直接用于亲核氟化反应。
目标水中的[18F]氟化物被SAX柱定量保留，无水[18F]氟化物的总回收率为92±5%（n = 10）。通过该程序获得的[18F]氟化物导致[18F]FDG、[18F]FET、[18F]FLT、[18F]FAZA和[18F]氟哌利多的放射化学产率为70 - 90%。
SAX树脂吸附的[18F]氟化物可用非水溶剂干燥并用[K(+)是2.2.2的子集]OH(-)在CH3CN中洗脱。新方法产生的[K(+)是2.2.2的子集]F(-)的反应性与通过共沸干燥获得的[18F]氟化物相当。所述程序总体上促进了18F放射性药物的自动化生产，并且还可能简化用于18F放射性示踪剂生产的微流控装置的使用。
