Labeling of tannic Acid with technetium-99m for diagnosis of stomach ulcer.

Tannic acid is a polyphenolic compound that could be labeled with technetium-99m. To produce about 90% yield of  (99m)Tc-tannic acid in acidic media (pH), the conditions required were 150 μg tin chloride, 30 min reaction time, and 200 μg of the substrate. (99m)Tc-tannic was stable for 6 h. Oral biodistribution of (99m)Tc-tannic showed that it concentrated in the stomach ulcer to reach about 50% of the total injected dose at 1 h after orall administration. This concentration of (99m)Tc-tannic in stomach ulcer may be sufficient to radio-image the presence of ulcer in the stomach.