Abstract
18F-FDG is a glucose analog in which the hydroxyl group on the second carbon is substituted with 18F, being used as an indicator
of glucose uptake and cell viability.
The aim of this work was to synthesize the 18F-FDG and to validate the methodology for the assessment of its both radiochemical
and chemical purities, according to the European Pharmacopoeia. The proposed methodology encompasses three
chromatographic methods: radio-HPLC, radio-TLC and HS/GC.
Radiochemical impurities may originate from radionuclide production, incomplete purification and radiolysis after synthesis.
Chromatographic methods should effectively separate these species, as radioactive impurities can affect the clinical outcome of
positron emission tomography imaging studies because of nonspecific uptake. Chemical impurities, on the other hand, can affect
nucleophilic substitution mechanism. Keeping these contaminants at as low concentrations as possible is the key of a successful
synthesis. Therefore, the determination of both type of impurities in short time is an essential step in characterizing of each batch,
due to the rapid decay of 18F (109.8 min half-life).
By optimizing the operating conditions, both chemical and radiochemical impurities analysis can be done within 12 min. The
optimized methodology shows good performance: linearity, specificity, precision, limit of quantification, limit of detection and
reproducibility, thus it could be successfully applied in the quality control tests of radiopharmaceuticals according to the
European Pharmacopoeia.