Synthesis and characterization of new Tc-99m-radiopharmaceuticals with dithiobenzoate derivatives for the study of septic inflammatory processes

Improved methods for the preparation of 99mTc-radiopharmaceuticals containing dithiobenzoate ligands, in sterile and pyrogen free conditions, are described. These procedures are based on the reaction of these ligands either with [99mTc] pertechnetate in the presence of a strong reducing agent (HCl/tertiary phosphine, SnCl2·2H2O), or with pre-reduced complexes obtained from different kit formulations. All the preparations led to the high-yield formation of the neutral and lipophilic 99mTc-complex [99mTc][Tc(S3CPh)2(S2CPh)], which is analogous to the corresponding compounds obtained with rhenium and the long-lived β-emitting isotope technetium-99 g recently described. HPLC analysis and thin layer chromatography were used to confirm the characterisation of the resulting 99mTc-radiopharmaceutical which was found to be potentially suitable for blood-cell labelling as applied to the diagnosis of inflammatory processes. Copyright © 2003 John Wiley & Sons, Ltd.