The invention relates to novel particulate drug-delivery systems based on apolymer support containing at least onelinear, branched or cross-linked polymer in a fraction of over 50 percent byweight in relation to the total weight of the support. Thesystem is characterised in that at least one signal substance for transportthrough a biological barrier and at least one active ingredientare stored, the support, signal substance and active ingredient having nocovalent links and no active-ingredient specific and signalsubstance specific coordinative links between one another.
