A film-shaped therapeutic system comprising at least two layers connected with each other, for transmucosal administration of active substances. The system has a layer which is mucoadhesive in an aqueous environment and a mono-layered or multi-layered backing layer. At least one of these layers contains an active substance. The mucoadhesive layer is capable of swelling in an aqueous media, but is insoluble or only poorly soluble in an aqueous media.