title: Towards developing a non-SnCl2 formulation for RP444, a new radiopharmaceutical for thrombus imaging.
abstract: There are many factors influencing the yield and radiochemical purity (RCP) of the radiopharmaceutical RP444. These include heating temperature, heating time, pH, the use of a buffering agent and a bulking agent, as well as the component (XV066, tricine, TPPTS, and Na99mTcO4) concentration. Through a series of radiolabeling experiments, we found that a formulation comprised of 20 microg of XV066, 6.5 mg of tricine, 40 mg of mannitol, 5 mg of TPPTS, and 0.1 mg of Pluronic acid dissolved in 1.0 mL of 250 mM succinate buffer (pH 5.0) gives the best RCP for RP444. The formulation can be lyophilized to form a stable crystal "cake". The radiolabeling is achieved by adding 1.5 mL generator eluant (33-133 mCi of Na99mTcO4) to a lyophilized vial and heating the reaction mixture at 100 degrees C for 10 min. Using this formulation, RP444 is prepared consistently in high yield with RCP > or = 90%. Formation of [99mTc]colloid is minimal (< 0.5%).
authors.affiliation: DuPont Pharmaceuticals Company, Medical Imaging Division, 331 Treble Cove Road, North Billerica, Massachusetts 01862, USA. shuang.liu@dupontpharma.com
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.forename: D S
authors.initials: DS
authors.lastname: Edwards
authors.forename: A R
authors.initials: AR
authors.lastname: Harris
authors.forename: M C
authors.initials: MC
authors.lastname: Ziegler
authors.forename: M J
authors.initials: MJ
authors.lastname: Poirier
authors.forename: B A
authors.initials: BA
authors.lastname: Ewels
authors.forename: W R
authors.initials: WR
authors.lastname: Diluzio
authors.forename: P
authors.initials: P
authors.lastname: Hui
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005998:Glycine / Q000031:analogs & derivatives / Q000737:chemistry; D008353:Mannitol / Q000737:chemistry; D015609:Organotechnetium Compounds / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000737:chemistry*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry; D013927:Thrombosis / Q000000981:diagnostic imaging*; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: C400057:99mTc(HYNICtide)(tricine)(TPPTS); D015609:Organotechnetium Compounds; D010456:Peptides, Cyclic; D019275:Radiopharmaceuticals; D013501:Surface-Active Agents; D017971:Tin Compounds; C023599:stannous chloride; D008353:Mannitol; D005998:Glycine; C100184:tricine