Highly efficient solid phase supported radiosynthesis of [<sup>11</sup>
C]PiB using tC18 cartridge as a “3-in-1” production entity
作者:Mehdi Boudjemeline、Robert Hopewell、Pierre-Luc Rochon、Dean Jolly、Iness Hammami、Sylvia Villeneuve、Alexey Kostikov
DOI:10.1002/jlcr.3569
日期:2017.12
Pittsburgh compound B ([11C]PiB) is the gold standard positron emission tomography (PET) tracer for the in vivo imaging of amyloid plaques. Currently, it is synthesized by either solution chemistry or using a “dry loop” approach followed by HPLC purification within 30 minutes starting from [11C]CO2. Here, we report a novel, highly efficient solid phase supported carbon-11 radiolabeling procedure using commercially available disposable tC18 cartridge as a “3-in-1” entity: reactor, purifier, and solvent replacement system. [11C]PiB is synthesized by passing gaseous [11C]CH3OTf through a tC18 cartridge preloaded with a solution of precursor. Successive elution with aqueous ethanol solutions allows for nearly quantitative separation of the reaction mixture to provide chemically and radiochemically pure PET tracer. [11C]PiB suitable for human injection is produced within 10 minutes starting from [11C]CH3OTf (20 min from [11C]CO2) in 22% isolated yield not corrected for decay and molar activity of 190 GBq/μmol using 0.2 mg of precursor. This technique reduces the amount of precursor and other supplies, avoids use of preparative HPLC and toxic solvents, and decreases the time between consecutive production batches. Solid phase supported technique can facilitate [11C]PiB production compliant with Good Manufacturing Practice (GMP) and improve synthesis reliability.
匹兹堡化合物 B([11C]PiB)是淀粉样蛋白斑块体内成像的黄金标准正电子发射断层扫描(PET)示踪剂。目前,它是通过溶液化学或 "干循环 "方法合成的,然后在 30 分钟内从[11C]CO2 开始进行 HPLC 纯化。在此,我们报告了一种新型、高效的固相支持碳-11 放射性标记程序,该程序使用市售一次性 tC18 盒作为 "三合一 "实体:反应器、纯化器和溶剂置换系统。气态[11C]CH3OTf 通过预先装入前体溶液的 tC18 盒合成[11C]PiB。通过乙醇水溶液的连续洗脱,可以几乎定量地分离反应混合物,从而获得化学和放射化学纯 PET 示踪剂。从[11C]CH3OTf(20 分钟内从[11C]CO2)开始,在 10 分钟内就能生产出适合人体注射的[11C]PiB,分离产率为 22%(未修正衰变),摩尔活性为 190 GBq/μmol(使用 0.2 毫克前体)。该技术减少了前体和其他耗材的用量,避免了制备型高效液相色谱和有毒溶剂的使用,并缩短了连续生产批次之间的间隔时间。固相支持技术可促进符合药品生产质量管理规范(GMP)的[11C]PiB 生产,并提高合成的可靠性。