[Problem] To provide a formulation containing Brilliant Blue G (BBG) for which variation in physical properties of the formulation has been suppressed. [Solution] A composition containing Brilliant Blue G (BBG) or a pharmaceutically acceptable salt thereof, and a positional isomer of Brilliant Blue G (BBG) or a pharmaceutically acceptable salt thereof, the composition containing 90 wt% or more and 100 wt% or less of one or both of Brilliant Blue G (BBG) and the pharmaceutically acceptable salt thereof in the total of the Brilliant Blue G (BBG), the pharmaceutically acceptable salt of Brilliant Blue G (BBG), the positional isomer of Brilliant Blue G (BBG), and the pharmaceutically acceptable salt of the positional isomer of Brilliant Blue G (BBG).
