New99mTc-diiodine substituted IDA derivative (DIIODIDA) for hepatobiliary imaging

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