STABILITY STUDY OF 2-( 18 F)FLUORO-2-DEOXY-D-GLUCOSE ( 18 FDG) STORED AT ROOM TEMPERATURE BY PHYSICOCHEMICAL AND MICROBIOLOGICAL ASSAYS

The most widely used radiopharmaceutical in the expanding medical imaging technology of Positron Emission Tomography (PET) is 2-[ 18 F]fluoro-2-deoxy-D-glucose ( 18 FDG). The increasing demand for 18 FDG requires reliable production in large amounts. The synthesis of 18 FDG is based on a nucleophilic substitution of the triflate-leaving group from the precursor, mannose triflate, in the presence of Cryptand 2.2.2, as a phase-transfer agent. After labeling, the removal of the acetyl protecting groups from resulting 2-[ 18 F]fluoro-1,3,4,6-tetra-Oacetyl-D-glucose is performed by alkaline hydrolysis, followed by purification and final filtration (0.22 µm). It was reported that 18 FDG decomposes in vitro , resulting in the degradation of the radiochemical purity with time. The aim of this study was to evaluate physicochemical and microbiological stability of 18 FDG, stored at room temperature (15-30 °C), at different time intervals. It was investigated how the quality of this radiopharmaceutical varies with time under the influence of environmental factors. 18 FDG pH, radionuclidic identity and purity, radiochemical identity and purity, chemical purity, residual solvents, bacterial endotoxins and sterility were evaluated according to the United States Pharmacopeia 31ed. analytical methods and acceptance criteria. The results suggest that 18 FDG has physicochemical and microbiological stability up to 10 hours after the end of synthesis, under experimental conditions.