title: Kinetic stability studies on yttrium(III)-1,4,7,10- tetraazacyclododecane-1,4,7,10-tetraacetic acid by free-ion selective radiotracer extraction.
abstract: Free-ion selective radiotracer extraction (FISRE) using no-carrier-added (90)Y has been applied to assess the dissociation kinetics of yttrium(III)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (Y-DOTA), a radiopharmaceutical precursor with a remarkable kinetic stability. In order to extend the operationally defined detection window, a complemental FISRE-based experiment has been successfully developed. Within a time frame of approximately 10 half-times of (90)Y (t(1/2) = 61.4 h), the complex Y-DOTA has been observed to form two kinetically distinguishable species with significantly different kinetic properties. The time-dependent speciation was measured to be sensitive to pH variations even in the neutral pH range (4.5-7.4) whereas the impact of ionic strength changes is negligible.
authors.affiliation: Institut für Radiochemie, Technische Universität München, Walther-Meissner-Strasse 3, 85748 Garching, Germany. jur@rad.chemie.tu-muenchen.de
authors.forename: Denis
authors.initials: D
authors.lastname: Jurkin
authors.forename: Franz Josef
authors.initials: FJ
authors.lastname: Gildehaus
authors.forename: Birgit
authors.initials: B
authors.lastname: Wierczinski
mesh_terms: D004355:Drug Stability; D006207:Half-Life; D006571:Heterocyclic Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009942:Organometallic Compounds / Q000737:chemistry*; D011849:Radioactive Tracers; D019275:Radiopharmaceuticals / Q000737:chemistry*; D015019:Yttrium
chemical_list: D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; D011849:Radioactive Tracers; D019275:Radiopharmaceuticals; C113625:yttrium(III)-1,4,7,10-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid; D015019:Yttrium