A Simple, Rapid and Efficient Preparation of ^99mTc-Compounds by Electrolysis (II) ^99mTc-Stannous Hydroxide, ^99mTc-EDTA

Abstract

As previously reported, the electrolysis method is more simple and convenient for labeling of^99mTc than the other conventional methods. We further expanded the application of this method to the other compounds and confirmed that this method can be applied for labeling of stannous hydroxide and^99mTc-EDTA. We have experimentally determined^99mTc-EDTA can be used for the measurement of GFR and^99mTc-stannous hydroxide for the liver scanning.
By using Pt-Sn electrodes, better result was obtained in labeling efficiency of both^99mTc-EDTA and^99mTc-stannous hydroxide than by Pt-Zr electrodes.
^99mTc-EDTA was prepared by adding^99mTcO^-₄soln. to Sn-EDTA soln. which was preivously produced by electrolysis. The efficiency of chelation averaged more than 94 % by allowing this mixture for about 15 minutes. ^99mTc-EDTA and¹⁶⁹Yb-DTPA were simultaneously injected in an adult rabbit, and almost the same GFR values were obtained as 15.6 mllmin and 16.0 ml/min, respectively.
As for^99mTc-stannous hydroxide, chromatographic studies have shown that electrolysis with 0.1-0.3 coulomb gives a labeling efficiency of more than 98%. When injected into mice, more than 90% of this compound was taken up by liver.
As the results of further investigations, we found this electrolysis method can be applied for labeling of several other compounds such as polyphosphate and bleomycin. When this reaction is aseptically performed in sterile 0.9% NaCl soln., the resulting solution is ready for injection; this is considered to be an advantage for the medical use.