Process for the preparation of a patch as a transdermal therapeutic system for releasing active substances onto the skin with the release of a stepped active substance

摘要

Transdermal patches for controlled release of a drug comprise at least one drug reservoir in contg. with a drug-contg. release-controlling matrix, with a backing layer on the skin-distal side of the matrix and an adhesive layer on the skin-proximal side. The size and posn. of each drug reservoir are such that in at least one direction, the distance between the reservoir and the drug delivery surface of the matrix is greater than the diffusion path length of at least one drug from its reservoir into the matrix during the period of application.