Synthesis and characterization of 99mTc‐labelled biologically active molecules using borohydride exchange resin as a reducing agent for the preparation of radiopharmaceuticals

A novel and efficient method for preparing ^99mTc‐complexes of radiopharmaceuticals has been developed by reacting [^99mTc]pertechnetate with a ligand in the presence of borohydride exchange resin (BER) as a reducing agent. The latter is stable over a wide range of pH (2–11) and thus can be used with biologically active compounds without the formation of insoluble ^99mTcO₂ or SnO₂ colloids. Since the radiolabelled complexes are produced with high radiochemical purity and labelling efficiency under milder conditions than those required for the conventional reducing agents, the latter can be replaced. The method is expected to be applicable to the preparation of ^99mTc‐radiopharmaceuticals. Copyright © 2004 John Wiley & Sons, Ltd.