Labeling of omeprazole with technetium-99m for diagnosis of stomach

Omeprazole, a proton pump inhibitor, was labeled with 99m Tc to obtain 99m Tc-omeprazole in ∼96% yield in basic media. The optimum conditions were as follows: pH 9, 50 μg of SnCl2·2H2O, 30 min, and 3 mg of the substrate. 99m Tc-omeprazole was stable for 6 h. Intravenous biodistribution of 99m Tc-omeprazole showed that it concentrated in the stomach ulcer to reach about 22% of the total injected dose at 1 h post injection. This concentration of 99m Tc-omeprazole in stomach ulcer may be sufficient for ulcer imaging.