Comparative examinations of 99mTc-DMS preparations obtained by labelling dimercaptosuccinate kits with different formulations. I. Comparison of chemical and biological characteristics of Tc P-5 and TCK-12 kits.

The chemical and biological properties of two freeze-dried DMS kits for labelling with 99mTc (Tc P-5, manufactured by Boris Kidric Institute, Vinca, and TCK-12, by CIS, Saclay) were compared. A method for the determination of the radiochemical composition of the injection solution is proposed: ascending Whatman 31 paper chromatography in 50% aqueous methanol. The chromatographic results correspond to the biologic activity of the preparations. The biodynamics of both radiopharmaceuticals were determined at intervals in rats. Maximum renal concentrations were achieved at 3-4 hrs post injection (52% kidney and 3% liver uptake for Tc P-5; 59% kidney and 6-8% liver uptake for TCK-12). The bench-lifes of the injection solutions were compared by determining organ distribution after standing of the solutions for 0, 2 and 4 hrs. The Tc P-5 preparation was more stable, since the renal and hepatic concentrations were nearly constant. On the other hand, the hepatic concentration of TCK-12 was increasing during aging of the solution with a simultaneous decrease in renal concentration.