Automated production of [18F]FDDNP using a TRACERlab MXFDG

[18F]FDDNP has been recently described as a potent tracer to image amyloid plaques in vivo by positron emission tomography. Such a tool will be advisable to diagnose patient with mild cognitive impairment, to follow the disease progression and to evaluate new therapies. To make this radiopharmaceutical affordable for the clinicians, we developed an automated method for [18F]FDDNP radiosynthesis using a commercial [18F]FDG unit. Radiolabeling with fluorine-18 was carried out by a [18F]fluoro-detosylation reaction on the precursor 2-(1-{6-[(2-tosyloxyoethyl)(methyl)amino]-2- naphthyl}ethylidene)malononitrile. The reaction was performed in acetonitrile for 15 min at 90 C, and then the reaction mixture was injected into a semi-preparative high-pressure liquid chromatography. The desire [18F]FDDNP fraction was collected, and an SPE was performed. The [18F]FDDNP was formulated in a sodium chloride/ethanol solution followed by a sterile filtration. Stability of [18F]FDDNP was studied after 4 h and radiochemical purity of [18F]FDDNP remained ≥98%. The overall decay-corrected radiochemical yield was 15±3% (n = 8). Radiochemical purity was ≥98% and the specific activity was 164±25 GBq/μmol at EOS. Pharmaceutical controls, bio-burden, sterility, bacterial endotoxin and residual solvent tests were performed. The results were in accordance with the European Pharmacopoeia and demonstrated our ability to produce [18F]FDDNP with a pharmaceutical grade and a high reproducibility. (authors)