摘要 |
The present invention relates to a therapeutic system for the retarded and controlled transdermal and transmucous administration of active substances via an impermeable backing layer, an active substance containing reservoir, a substantially drug-free but drug-permeable layer, and a removable protective layer, whereby the drug-free layer is brought into contact with the active substance reservoir only immediately prior or after application and then lies between reservoir and application surface, whereby at least a portion of the active substance diffusing from the reservoir is converted in the retardation layer into a non-bioavailable form. In this connection, the conversion into the non-bioavailable form may be carried out either by immobilization of the active substance, by chemical reactions, or by physical interactions.
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