New Tc-99m-diiodine substituted IDA derivative (DIIODIDA) for hepatobiliary imaging

A new diiodine substituted LDA derivative, 2,4-diiodine-6-methyl IDA (DIIODIDA) was synthesized and labeled with Tc-99m. It was established that Tc-99m-DIIODIDA had high radiochemical purity. Biodistribution and influence of bilirubin on Tc-99m-DIIODIDA biokinetics has been studied in rats and compared to the corresponding results for Tc-99m-SOLCOIODIDA. Related to Tc-99m-SOLCOIODIDA, Tc-99m-DIIODIDA has much better biliary exretion (55.18 versus 43.63%). No change of Tc-99m-DIIODIDA biokinetics, under influence of bilirubin was noticed. Biliary excretion of Tc-99m-SOLCOIODIDA has been reduced for about 60%. The protein binding of Tc-99m-DIIODIDA and Tc-99m-SOLCOIODIDA were also determined, using in vitro method of precipitation. These results showed that Tc-99m-DIIODIDA hepatobiliary imaging agent is superior to the presently used Tc-99m-monoiodine IDA derivatives