The present invention relates to a transdermal therapeutic system for administering an active substance through the skin, comprising:a) a cover layer,b) a reservoir present on the cover layer, comprising a polymer matrix comprising the active substance,c) an adhesive layer present on the reservoir comprising a contact adhesive, andd) a removable layer present on the adhesive layer,the active substance being rivastigmine, a physiologically compatible salt, hydrate, solvate or derivative thereof,characterized in that the polymer matrix of the reservoir comprises neither hydroxyl groups nor carboxyl groups.
