Florbetapir F-18 is a fluorine-18-labeled molecular imaging agent used with positron emission tomography (PET) to estimate β-amyloid neuritic plaque density in the brain. It is associated with the diagnostic evaluation of adult patients with cognitive impairment who are being assessed for Alzheimer's disease and other causes of cognitive decline.
Florbetapir F-18 is chemically identified as an aromatic ether containing a pyridine ring and a fluorine-18-labeled fluoroethoxy chain. PubChem lists the molecular formula as C20H25FN2O3 and molecular weight as 359.4 g/mol. Its CAS Registry Number is 956103-76-7.
Florbetapir F-18 is a radioactive diagnostic agent. The F-18 radionuclide emits positrons and has a physical half-life of approximately 109.8 minutes, allowing the tracer to be used for PET imaging.
The compound binds to β-amyloid aggregates, enabling PET imaging of amyloid plaque distribution in the brain.
Florbetapir F-18 is used as a PET imaging agent for estimating β-amyloid neuritic plaque density in adults with cognitive impairment undergoing evaluation for Alzheimer's disease and other causes of cognitive decline.
Following administration, Florbetapir F-18 binds to β-amyloid aggregates. Fluorine-18 undergoes positron emission, and the resulting PET signal allows visualization of the distribution of β-amyloid plaques in the brain.
FDA describes Amyvid as a sterile, non-pyrogenic, clear and colorless solution for intravenous administration. The current label specifies 0.1–19 µg/mL florbetapir, 500–1,900 MBq/mL florbetapir F-18 at end of synthesis, and a solution pH of 5.5–8.0.
Fluorine-18 has a physical half-life of 109.8 minutes and decays by positron emission. The principal photons used for PET imaging are 511 keV annihilation photons.
Florbetapir F-18 is a specialized radiopharmaceutical and therefore requires analytical controls different from those normally applied to conventional non-radioactive APIs. FDA chemistry review describes characterization of the drug substance using radiochemical identity, radiochemical purity, specific activity, strength, radionuclidic identity and radionuclidic purity.
Applicable finished-product controls can include:
Florbetapir F-18 requires specialized radiopharmaceutical handling because it contains radioactive fluorine-18. Handling, shielding, storage and administration must comply with applicable radiation-safety and radiopharmaceutical regulations.
Florbetapir F-18 injection is supplied as a sterile solution in suitable radiopharmaceutical containers. The FDA label describes Amyvid as a ready-to-use sterile solution for intravenous administration.
Florbetapir F-18 provides a molecular imaging approach for assessing β-amyloid plaque density in the brain. Its short-lived fluorine-18 radionuclide provides a practical PET imaging window while allowing visualization of amyloid-associated tracer uptake.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.5% |
| Heavy Metals | NMT 20 ppm |
| pH (1% Solution) | 2.0 – 4.0 |
| Individual Impurity | NMT 0.5% |