Chromatographic Separation and Utilization of Labeled 99m Tc-Valsartan for Cardiac Imaging

Abstract

A procedure was developed for preparing high radiochemical purity 99mTc-valsartan with yield of 98%. The complex was prepared by mixing of valsartan with SnCl2.2H2O solution and the pH of the mixture was adjusted to 8 then mixed with a freshly eluted 99mTc O4- (~400 MBq), shacked at room temperature for 30 min. The radiochemical yield and purity of the labeled product were determined individually by HPLC, paper chromatography and paper electrophoresis. Biodistribution studies were carried out in normal Albino Swiss mice at different time intervals after administration of 99mTc-valsartan. The labeled compound cleared from the systematic circulation within 2 h afteradministration, and the majority of organs showed significant decrease in the uptake of 99mTc-valsartan. The heart uptake of 99mTc-valsartan was sufficiently high for using this agent as myocardial imaging agent.