FORMULATION OF A SINGLE-COMPONENT KIT FOR THE PREPARATION OF TC-99M LABELED ETHYL CYSTEINATE DIMER - BIOLOGICAL AND CLINICAL-EVALUATION

Ethyl cysteinate dimer (ECD) labelled with reduced technetium-99m has recently been proposed as a promising radiopharmaceutical for brain pe rfusion imaging. In the present study a single-component kit formulati on has been developed, thus simplifying the radiolabelling procedure. A method of analysis by electropho resis has also been developed, perm itting identification of radiochemical impurities in the preparation. Tc-99m-ECD prepared by the single-component kit was further evaluated in primates and humans. The results demonstrated that the complex is s table in vivo, rapidly extracted and retained in the brain tissue for a sufficient time for single-photon emission tomography studies. There fore the present single-component kit formulation can be proposed as a reliable instant freeze-dried kit for routine preparation of Tc-99m-E CD required for scintigraphic assessment of regional cerebral blood fl ow.