188Re(V) COMPLEX OF CYCLAM , A STABLE RHENIUM-188 CORE POTENTIALFOR DEVELOPMENT OF THERAPEUTIC RADIOPHARMACEUTICAL

摘要

A method of labeling 188Re-cyclam (1, 4, 8, 11-Tetraazacyclotetradecane) in aqueousrnsolution with high labeling yield and high stability has been investigated. The macrocyclic ligand ofrncyclam bound to rhenium and formed a stable complex of dioxorhenium (V) cation, which may bernsuitable for nuclear medicine applications. The labeling was performed in the aqueous solution of 15rnmg potassium gluconate and 1 mg stannous chloride at pH above 5. After mixing with 5 – 10 mCi ofrn188ReO-rn4 and 1 mg cyclam, the reaction mixture was incubated at 80 ℃ for 60 minutes. The labelingrnefficiency and in vitro stability were determined by ITLC-SG in 0.9% NaCl system and by P.E. inrn0.05 M phosphate buffer pH 7.4 at 250 V for 45 min. The results showed high labeling efficiency uprnto 93% and high in vitro stability over 24 hours, less than 2% of free188ReO-rn4 loss from metal-ligandrncomplex.