title: Preparation and stability of ethanol-free solution of [18F]florbetapir ([18F]AV-45) for positron emission tomography amyloid imaging.
abstract: We have developed an ethanol-free formulation method of [(18) F]florbetapir ([(1) (8) F]AV-45) using a commercially available automated JFE multi-purpose synthesizer. We have also evaluated the radiochemical stability in an ethanol-free solution of [(18) F]AV-45 under visible light irradiation and dark conditions by comparison with a conventional 10% ethanol solution of [(18) F]AV-45. [(18) F]AV-45 was obtained with a radiochemical yield of 55.1 ± 2.2% (decay-corrected to end of bombardment), specific activity of 591.6 ± 90.3 GBq/µmol and radiochemical purity of >99% within a total synthesis time of about 73 min. The radiochemical purity of [(18) F]AV-45 formulated by dissolving the ethanol-free solution was found to decrease as a function of the period of exposure to visible light. In contrast, the visible light photolysis could be suppressed by adding 10% ethanol to the formulation or by avoiding exposure to visible light. In the radiosynthesis of [(18) F]AV-45 formulated by dissolving the ethanol-free solution, [(18) F]AV-45 could be obtained with high radiochemical purity and high stability by avoiding exposure to visible light.
authors.affiliation: Advanced Molecular Imaging Center, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu-city, Oita, 879-5593, Japan; Molecular Imaging Integration Unit, RIKEN Center for Molecular Imaging Science (CMIS), 6-7-3 Minatojima Minami-machi, Chuo-ku, Kobe-city, Hyogo, 650-0047, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Hayashi
authors.forename: Akiko
authors.initials: A
authors.lastname: Tachibana
authors.forename: Shusaku
authors.initials: S
authors.lastname: Tazawa
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Mizukawa
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Osaki
authors.forename: Yoko
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Riyo
authors.initials: R
authors.lastname: Zochi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurahashi
authors.forename: Hatsumi
authors.initials: H
authors.lastname: Aki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000814:Aniline Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D005026:Ethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry; D007553:Isotope Labeling / Q000379:methods*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D005026:Ethylene Glycols; D019275:Radiopharmaceuticals; C545186:florbetapir
keywords: Alzheimer's disease; [18F]AV-45; automated synthesis; disposable components; β-amyloid