Radiodiagnosis of peptic ulcer with technetium-99m-labeled esomeprazole

Abstract

Esomeprazole was labeled with ^99mTc in high (up to ~98.0%) radiochemical yield. The optimum conditions are as follows: pH 8, 50 μg of SnCl₂·2H₂O, 30 min, and 2 mg of the substrate. The complex is stable for 8 h. The reaction mixture was separated by gel chromatography using such eluents as NaCl solution and, phosphate, citrate, and carbonate buffer solutions. Free ^99mTcO₄^– and the complex were also efficiently separated by reversed-phase HPLC, paper chromatography, and electrophoreses. Intravenous biodistribution studies of ^99mTc-esomeprazole complex showed high uptake in the stomach ulcer, reaching about 30.5% ID/g at 1 h post injection. Such a high ^99mTc-esomeprazole uptake makes this agent promising for stomach ulcer imaging.