The invention relates to a transdermal therapeutic system for the controlled release of water-soluble pharmaceutical active ingredients from an aqueous phase, comprising an occlusive back layer, a central device facing the skin for releasing the agent, an adhesive layer concentrically surrounding the dispensing device and a removable protective film. Said device is made from a stationary solid phase and a liquid phase containing the active ingredient in aqueous solution, the solid phase being formed from a solid with a fleecy or spongy structure.