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

Two 99m Tc cores, 99m Tc tricarbonyl and 99m Tc-Sn(II), are compared in labeling of Lansoprazole (Lans). The optimum conditions of Lansoprazole labeling with 99m Tc in the presence of SnCl 2 ·2H 2 O as a reducing agent are as follows: pH 8, 100 μg of SnCl 2 ·2H 2 O, room temperature, 2 mg of lansoprazole, and 30 min; the maximum radiochemical yield was 98 ± 0.22%. The obtained 99m Tc Lansoprazole complex was stable in serum for up to 16 h. The optimum conditions of Lansoprazole binding with the 99m Tc tricarbonyl ([ 99m Tc(CO) 3 (H 2 O) 3 ] + ) core are as follows: pH 8, 2 mg of Lansoprazole, 100°С, 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 99m Tc 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.