[18F]fluoride Activation and 18F-Labelling in Hydrous Conditions—Towards a Microfluidic Synthesis of PET Radiopharmaceuticals
Olga Ovdiichuk, Salla Lahdenpohja, Quentin Béen, Laurent Tanguy, Bertrand Kuhnast, Charlotte Collet-Defossez- Chemistry (miscellaneous)
- Analytical Chemistry
- Organic Chemistry
- Physical and Theoretical Chemistry
- Molecular Medicine
- Drug Discovery
- Pharmaceutical Science
18F-labelled radiopharmaceuticals are indispensable in positron emission tomography. The critical step in the preparation of 18F-labelled tracers is the anhydrous F-18 nucleophilic substitution reaction, which involves [18F]F− anions generated in aqueous media by the cyclotron. For this, azeotropic drying by distillation is widely used in standard synthesisers, but microfluidic systems are often not compatible with such a process. To avoid this step, several methods compatible with aqueous media have been developed. We summarised the existing approaches and two of them have been studied in detail. [18F]fluoride elution efficiencies have been investigated under different conditions showing high 18F-recovery. Finally, a large scope of precursors has been assessed for radiochemical conversion, and these hydrous labelling techniques have shown their potential for tracer production using a microfluidic approach, more particularly compatible with iMiDEV™ cassette volumes.