To establish an optimized automatic synthesis method of ¹⁸F-fallypride, and evaluate its biodistribution and microPET/CT characteristics.

¹⁸F-fallypride was automatically prepared by AIO synthesis module and disposable cassette & reagents kit. The crude product was purified by a dedicated coupled column (HLB+ Alumin-N) to obtain the final product. Radiochemical purity and radiolabeling yield were determined. Parkinson′s disease (PD) model mice and rats were established. The radioactive distribution of different organs of PD model mice (n=24) were monitored. The distribution process of the agent in the SD rat brain (PD model, n=6; normal rat, n=6) were evaluated by microPET/CT imaging.

The radiochemical yield of ¹⁸F-fallypride synthesized by automatic synthesis module was stable at (10±1)% (n=5, no decay corrected). The total synthesis time was about 40 min. The radiochemical purity of ¹⁸F-fallypride was more than 95%, and the radiochemical purities were also over 95% after being stored in saline and serum for 120 min at room temperature. ¹⁸F-fallypride was mainly excreted by the kidneys, and it was less radioactive intake in the liver and spleen in PD mice. MicroPET/CT imaging showed that higher accumulation of ¹⁸F-fallypride was noted in corpus striatum and the SUV ratio of PD group was lower than that of control group (5.00±0.93 vs 6.53±1.96).

¹⁸F-fallypride can be successfully prepared automatically by improved multifunctional module, with the advantages of convenient preparation, stable radiochemical yield, satisfying purity and quality control, so it can be used in the follow-up standardized production of Good Manufacture Practice (GMP) system.

Pyrrolidines; Chemical synthesis; Positron-emission tomography; Tomography, X-ray computed; Mice; Rats