In a transdermal therapeutic system (TTS) (5) comprising a backing layer (1), a polymer layer (2) containing silicone adhesive in contact with the backing layer and a removable protective layer (3) in contact with the polymer layer, the contact side of the backing layer is finished with an adhesion-promoting layer (4) obtained by siliconization. Independent claims are also included for: (1) the production of a backing layer for use in a TTS, by siliconizing the surface to be contacted with a polymer layer provided with microreservoirs； and (2) the use of a siliconized backing layer in a TTS.
