99mtc-unithiol complex, a new radiopharmaceutical for kidney scintigraphy III. Studies of labelling unithiol with 99mtc.

Labelling of 2, 3-dimercaptopropane sodiumsulphonate (Unithiol) with 99mTc resulted in essentially three components in the GCS pofile: the top zone, a low-molecular Complex A and a high-molecular Complex B. In the presence of tin metal a fourth component, Complex C, could be distinguished. Complex A was relatively independent of pH, the proportion of Complex B increased with increasing pH. Methods were developed for preparing, with over 80% labelling efficiency, either Complex A or Complex B, each having high stability in the preparation vials and in human blood.