Abstract: The invention relates to a doubly packaged storage assembly (5) for an aqueous medical solution, more especially a contrast agent, comprising an overpackage (4) in which at least one flexible packaging container (3) is packaged and hermetically sealed, said container (3) being filled with an aqueous solution and sealed by means of a connector provided with a cap, in which storage assembly (5): the overpackage (4) comprises two superposed foils made of flexible or semi-rigid polymer materials, the first foil being transparent over its entire area and the second foil being opaque over its entire area; and the packaging container (3) comprises two superposed sheets made of polymer material and an access member at the distal end of which the connector and the cap are placed, the connector allowing the packaging container to be sealed after it has been filled with the aqueous solution.