FLUORODOPA F18 Solution for injection Ref.[11031] Active ingredients: Fluorodopa ¹⁸F

11.1 Chemical Characteristics

Fluorodopa F18 Injection is a radioactive diagnostic agent used in PET imaging. The active ingredient 6-[¹⁸F] Fluoro-L-3, 4-dihydroxyphenylalanine has the molecular formula of C₉H₁₀FNO₄ with a molecular weight of 214.18, and has the following chemical structure:

Fluorodopa F18 Injection is a sterile, pyrogen-free, clear, colorless solution. Each mL contains between 37 MBq/mL to 1,480 MBq/mL (1 mCi/mL to 40 mCi/mL) of no-carrier added Fluorodopa F18 (6-[¹⁸F] Fluoro-L-3, 4-dihydroxyphenylalanine) at the end of synthesis (EOS). There is 40.88 mg Na-EDTA, 140 mg ascorbic acid, and 663 mg ethanol in 28 mL ±1 mL sodium phosphate buffer. The pH of the solution is between 3 and 5.

11.2 Physical Characteristics

Fluorine F18 is a cyclotron produced radionuclide that decays by positron emission to Oxygen O-18 (stable) and has a physical half-life of 109.7 minutes. The principal photons useful for imaging are the dual 511 keV gamma photons, which are produced and emitted simultaneously in opposite direction following positron-electron annihilation (Table 2).

Table 2. Principal Radiation Emission Data for Fluoride F18:

^* Produced by positron annihilation

11.3 External Radiation

The point source air-kerma coefficient for F18 is 3.75 × 10^-17 Gy m²/(Bqs). The half-value layer (HVL) for the 511 keV photons is 5 mm lead (Pb). The range of attenuation coefficients for this radionuclide as a function of lead shield thickness is shown in Table 3. For example, the interposition of a 9 mm thickness of Pb, with a coefficient of attenuation of 0.25, will decrease the external radiation by 75%.

Table 3. Radiation Attenuation of 511 keV Photons by lead (Pb) shielding:

For use in correcting for physical decay of this radionuclide, the fractions remaining at selected intervals after calibration are shown in Table 4.

Table 4. Physical Decay Chart for Fluorine F18:

^* Calibration time