| abstract |
[PROBLEMS] To provide a composition of a radioactive fluorine-labeled amino acid compound capable of inhibiting radiation decomposition. (Solution) In a composition comprising a solution containing a radioactive fluorine-labeled amino acid compound as an active ingredient, the pH of the solution is maintained at 2.0 to 5.9, more preferably 2.0 to 4.9, thereby suppressing the radiation decomposition. In addition, it is possible to suppress radiation decomposition superimposedly by adding a pharmaceutical additive for suppressing radiation decomposition such as sugar, sugar alcohol, and tallow salt while maintaining the pH at 2.0 to 5.9. |