Radiopharmaceutical Production Quality Control Testing Product Stability STOP

Product Stability When the activity concentration of [ 18 F]FDG is increased to the hundreds of mCi/mL, [ 18 F]fluoride is the main active product of autoradiolysis and becomes the most important radiochemical impurity. The current US Pharmacopeia (USP) stipulates the minimum radiochemical purity for [ 18 F]FDG as no less than 90% of the total radioactivity assumed to be present at the time of administration to a patient. In contrast, the current European Pharmacopoeia (EP) stipulates the minimum radiochemical purity for [ 18 F]FDG and [ 18 F]FDM as no less than 95% of the total radioactivity of which the [ 18 F]FDM fraction should not exceed 10% of the total radioactivity. Contents Acceptance Criteria Discussion Procedure STOP

Radiopharmaceutical Production QC Testing Product Stability Contents Acceptance Criteria Discussion Procedure STOP Acceptance Criteria Acceptance Criteria: FDG must comply with the requirement for parenteral preparations, and must pass the product stability test. This test needs to be carried out at the highest activity level and smallest volume that would be expected under normal production conditions. Procedure: 200 μL samples of FDG taken within a few minutes of the end of synthesis should be stored at room temperature (22 °C) and aliquots (0.1–5 μL as required to offset decay) can be analysed by radioTLC to monitor the build up of the main decomposition product (free [ 18 F]fluoride) for up to 14 h post synthesis.

Radiopharmaceutical Production QC Testing Product Stability Contents Acceptance Criteria Discussion Procedure STOP Discussion Discussion: The product must be validated using this test and revalidated on a periodic basis or whenever the procedure of synthesis is changed or there is an increase in yield so that the activity per unit volume is increased. To study the impact of stabilisers, samples of FDG (50–100 μL) can be treated with reagents to the concentrations shown and both treated and untreated FDG samples subjected to a room temperature stability study. Separate stability studies ned to be performed to observe the effect of (i) radioactive concentration, (ii) added ethanol, (iii) added hydrogen peroxide, (iv) added ascorbic acid, (v) added sodium nitrite, (vi) added sodium thiosulfate and (vii) added sodium iodide upon the decomposition of FDG.

Radiopharmaceutical Production QC Testing Product Stability Contents Acceptance Criteria Discussion Procedure STOP Stability Procedure A plot of the amount of fluoride present in the sample should be generated to show that the purity of the FDG remains with the acceptance limits during the normal lifetime of the FDG. Link to Demonstration (UNDER CONSTRUCTION)

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