Analysis of 99mTc-pyridoxylidene-glutamate complex formation and its preparation with tin-adsorbed-resin: Sn-Resin kit method.

99mTc-Pyridoxylidene-glutamate (Tc-PG) was introduced in 1975 by Baker et al. as a cholescintigraphic agent. Nevertheless its routine use has been limited due to the autoclaving process involved. To shorten the labeling procedure, an analysis of Tc-PG complex formation using the stannous chloride method was carried out. Sn-Resin (stannous ion adsorbed onto cation exchange resin) was used for labeling a stable Tc-PG with high efficiency. A preautoclaved complex of pyridoxal and glutamate was required but the labeling procedure took only 10-15 min after the elution of 99m-TcO4- from the generator. Formation of a complex other than a 99mTc-complex of the Schiff -base ligand pyridoxylidene-glutamate is discussed. The new formulation of a Tc-PG kit (Sn-Resin) simplified the labeling method and reproducible data to that already reported by Baker was obtained in chromatographic studies. Its suitability in hospital departments has already been shown in clinical studies.