| abstract |
The present invention relates to a transdermal therapeutic system for transdermally administering an active ingredient to a backing layer comprising (a) a backing layer, and (b) an active ingredient, polyisobutylene, a gel-forming agent, and a plasticizer. A part of the active ingredient in the reservoir is in the form of insoluble particles, and the content of the gel forming agent in the reservoir is 4% by weight or less with respect to the total weight of the reservoir. And a transdermal therapeutic system, wherein the active ingredient is fentanyl or a similar compound thereof. |