[11C]Metoclopramide is a new radiotracer for investigating the activity of P-glycoprotein at the blood-brain barrier. A highly stable and reproducible radiosynthesis is a prerequisite for clinical studies applying [11C]metoclopramide or other 11C-labelled radiotracers, therefore all potential pitfalls must be identified and monitored to allow a stable process. Long-term production (n = 94 in a time range of approximately 2 years) of [11C]metoclopramide synthesized on two commercially available synthesizers yielded 3.9 ± 2.0 GBq of product with a molar activity of 132 ± 164 GBq/μmol and an overall success rate of 93%. During all successful productions, the product quality was in accordance with the recommendations of the European Pharmacopoeia. The most common pitfalls that were identified for the radiosynthesis included poor turnover into [11C]CH3OTf, decomposition of the solvent or insufficient semi-preparative HPLC performance. The study provides long-term insight in the improved, robust and stable preparation of [11C]metoclopramide for human use.

中文翻译：

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[11C]甲氧氯普胺全自动放射合成的缺陷及解决方案

[11C]甲氧氯普胺是一种新的放射性示踪剂，用于研究血脑屏障中 P-糖蛋白的活性。高度稳定和可重复的放射合成是应用 [11C] 甲氧氯普胺或其他 11C 标记的放射性示踪剂的临床研究的先决条件，因此必须识别和监测所有潜在的缺陷以实现稳定的过程。在两个市售合成器上合成的 [11C] 甲氧氯普胺的长期生产（n = 94 在大约 2 年的时间范围内）产生了 3.9 ± 2.0 GBq 的产物，摩尔活性为 132 ± 164 GBq/μmol，总体成功率 93%。在所有成功的生产过程中，产品质量均符合欧洲药典的建议。放射性合成最常见的缺陷包括转化为 [11C]CH3OTf 的转化率低、溶剂分解或半制备型 HPLC 性能不足。该研究为人用 [11C] 甲氧氯普胺的改进、稳健和稳定制备提供了长期见解。