Technetium-99m radiopharmaceutical preparation by surface adsorbed stannous ions

A method of producing technetium-99m (99mTc) radiopharmaceuticals is described, where reduction of pertechnetate occurs through stannous ions adsorbed on the surface of an infusion catheter. This leads to radiopharmaceuticals containing microgram quantities of stannous ions and that, therefore, results in minimal blood-pool labeling and essentially the elimination of tin colloids. Other advantages of the method include a reduction in quantities of ligand required and the possibility to mass produce the "tinned" catheters as technetium "reduction" kits. A wide variety of 99mTc radiopharmaceuticals have been prepared in high yield. Excellent biodistribution in several of these is demonstrated.