Tc-DMSA complex preparation: the effect of pH and tin chloride amount on reaction

Labelling of meso-2,3-dimercaptosuccinic acid (DMSA) with technetium-99m was reinvestigated. Dependence of the [sup.99m]Tc-DMSA complex formation on the molar ratio of DMSA:reducing agent (Sn[Cl.sub.2] 2[H.sub.2]O) and pH was studied. Five different types of [sup.99m]Tc-DMSA complexes were determined. Especially three different complexes were established in the clinically used and prepared DMSA kit labelled with [sup.99m]Tc under alkaline condition. This radiopharmaceutical is used as imaging agent of the primary medullary carcinoma in the thyroid gland and different metastasis types. The existence of all complexes was observed by paper chromatography, paper electrophoresis and high performance liquid chromatography. Keywords Radiopharmaceuticals * [sup.99m]Tc * DMSA complex * pH * Sn[Cl.sub.2] 2[H.sub.2]O