KIT FORMULATION FOR THE PREPARATION OF RADIOLABELED IODODEOXYURIDINE BY DEMETALATION

The fastest and most reliable preparation of radiolabeled 5-iodo-2'-de oxyuridine (IUdR) is accomplished by iododemetallation. Methods: We d escribe a kit formulation for the preparation of IUdR by demercuratio n whereby [I-123/I-125/I-131]IUdR is synthesized virtually instantaneo usly following the incubation of an aqueous solution of the chloromerc uric precursor with (NaI)-I-123/I-125/I-131 in the presence of Iodogen , We also report the conditions for the radiosynthesis of IUdR by dest annylation of the tributylstannyl precursor using hydrogen peroxide as the oxidant. Results: In each case, the total procedure is completed in 5 min. HPLC indicates the total transformation of iodide into IUdR with no detectable UV-absorbing by-products, The metal content of the sample is low. The product, therefore, does not require purification, Conclusion: IUdR can be prepared instantly, by either demercuration o f ClHgUdR or destannylation of Bu(3)SnUdR. The use of a mercuric precu rsor favors a kit formulation since the metallic derivative is stable when kept in aqueous solution, aliquoted in vials coated with the oxid ant, for up to 3 mo.