An improved Transdermal Delivery System (TDS) comprising a backing layer inert to the components of the matrix, a self-adhesive matrix containing an amine-functional drug and a protective foil or sheet to be removed priorto use, characterized in that the self-adhesive matrix consists of a solid or semi-solid semi-permeable polymer (1)wherein an amine functional drug in its free base form has been incorporated, (2) which is saturated with the aminefunctional drug and contains said drug as a multitude of microreservoirs within the matrix, (3) which is highly permeable for the free base of the amine functional drug, (4) which is impermeable for the protonated form of the amine functional drug, (5) wherein the maximum diameter of the microreservoirs is less than the thickness of the matrix. is provided. Said TDS provides for enhanced flux of the amine functional drug across the TDS/skin interface.