METHOD FOR PRODUCTION OF RADIATION DIAGNOSTIC IMAGING AGENT

摘要

[PROBLEMS] To provide a method for producing a radiation diagnostic imagi ng agent comprising an amino acid compound labeled with a radioactive haloge n as an active ingredient, which hardly causes the radiation-induced degrada tion of the active ingredient and has such a composition that the stability can be improved. [MEANS FOR SOLVING PROBLEMS] Disclosed is a method for prod ucing a radiation diagnostic imaging agent, which comprises the following st eps: a radioactive fluorine-labeled organic compound solution preparation st ep for preparing a solution containing an amino acid compound labeled with a radioactive halogen; and a dilution step for diluting the solution containi ng the organic compound labeled with the radioactive fluorine to adjust the radioactive concentration in the solution, wherein the method further compri ses an acid addition step for adding an acid to the solution containing the organic compound labeled with the radioactive fluorine after the radioactive fluorine-labeled organic compound solution preparation step and prior to th e dilution step, and the amount of the acid to be added in the acid addition step is a sufficient amount for adjusting the pH value of the solution afte r the dilution step to 2.0 to 5.9, for example, 0.40 to 2.8 mmol per 1 L of the solution after the dilution step.