The present invention relates to a transdermal therapeutic system, preferably a transdermal patch, having an active ingredient-containing matrix formed substantially of a water-insoluble base material, such as rubber and synthetic polymers, into which is incorporated water-soluble and/or water-swellable inclusion bodies, e.g. inclusion bodies formed from polyvinyl alcohol or polyethylene glycol, that further include micronized or nanoscale active ingredient particles.