Comparative Bioevaluation of ^99mTc Tricarbonyl and ^99mTc-Sn(II) Lansoprazole as a Model for Peptic Ulcer Localization

Two Tc-99m cores, Tc-99m tricarbonyl and Tc-99m-Sn(II), are compared in labeling of Lansoprazole (Lans). The optimum conditions of Lansoprazole labeling with Tc-99m in the presence of SnCl2 center dot 2H(2)O as a reducing agent are as follows: pH 8, 100 mu g of SnCl2 center dot 2H(2)O, room temperature, 2 mg of lansoprazole, and 30 min; the maximum radiochemical yield was 98 +/- 0.22%. The obtained Tc-99m Lansoprazole complex was stable in serum for up to 16 h. The optimum conditions of Lansoprazole binding with the Tc-99m tricarbonyl ([Tc-99m(CO)(3)(H2O)(3)](+)) core are as follows: pH 8, 2 mg of Lansoprazole, 100 degrees C, 30 min. The complex was stable in serum for up to 12 h. Biodistribution study of the first core on two different groups of mice (control group and ulcer-bearing group) showed comparatively high uptake in the ulcer group of mice, 77.8 +/- 1.1% ID/g at 30 min post-injection (higher than for the control group); at 24 h, the uptake decreased to 17.9% ID/g. Similar results were obtained with Tc-99m tricarbonyl Lansoprazole: 78.5% ID/g at 30 min post-injection and 24.6% at 24 h. Thus, both complexes are suitable as radiotracers for stomach ulcer imaging.