Simple, column purification technique for the fully automated radiosynthesis of [18F]fluoroazomycinarabinoside ([18F]FAZA).

A novel fully automated radiosynthesis procedure for the fluorine-18 analog of 1-alpha-D-(5'-deoxy-5'-fluoro-(1S,2R,3S,4S) arabinofuranosyl)-2-nitroimidazole ([(18)F]FAZA) using a commercially available combination column - Chromabond Set V (FDG-base-hydrolysis) - for purification was developed. [(18)F]FAZA was prepared via a one-pot, two-step synthesis using a nuclear interface nucleophilic synthesis module. Nucleophilic fluorination of the precursor molecule, 1-(2,3-di-O-acetyl-5-O-tosyl-alpha-D-arabinofuranosyl)-2-nitroimidazole, with no-carrier added [(18)F]fluoride followed by hydrolysis of the protecting groups with 0.3M NaOH was performed. Purification was carried out using the Chromabond Set V column without any modifications. The overall radiochemical yield obtained was 21.98+/-1.40% (n=5, without decay correction) within a total synthesis period of 51+/-1 min. The radiochemical purity was greater than 95% and devoid of any other chemical impurities. The reported method can easily be adapted in any commercial FDG synthesis module.