Development of a novel 99mTc-labelled brain perfusion agent

A method has been described for radiolabeling of salbutamol with technetium-99m (99mTc). To a 1 ml solution, containing 5 mg salbutamol and 2 mg of ascorbic acid, was added a clear solution (10 μl) of SnCl2.2H2O (100 μg) in distilled water. The pH of the solution was adjusted to 8.5, mixed gently with 10 mCi (370 MBq) of 99mTc elute and incubated at room temperature for 15 minutes. The resulting solution was passed through 0.22 μ filter and radiolabeled fraction was quantified using paper chromatography. The radiochemical analysis, employing the use of above mentioned radioanalytical technique, revealed that greater than 97% of the radioactivity was bound to salbutamol and rest of the activity was in the form of free pertechnitate (99mTcO4). Biological data, obtained after i. v. injection of 99mTc-Salbutamol to female albino rabbits, revealed a fair uptake in the brain at 30 min and 60 min post injection time intervals. On the basis of animal biodistribution data it is suggested that 99mTc-salbutamol can be successfully applied as a brain perfusion agent. (author)