Towards developing a non-SnCl2 formulation for RP444, a new radiopharmaceutical for thrombus imaging.
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%).
Liu
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DuPont Pharmaceuticals Company, Medical Imaging Division, 331 Treble Cove Road, North Billerica, Massachusetts 01862, USA. shuang.liu@dupontpharma.com
Edwards
D S
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Harris
A R
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Ziegler
M C
MC
Poirier
M J
MJ
Ewels
B A
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Diluzio
W R
WR
Hui
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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*
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