Matrix tablets with a dispersed active ingredient are the simplest concept in the design of dosage forms with modified drug release. If they contain a swelling polymer as an auxiliary substance, the release from these systems, after initial liberation of a portion of the active ingredient from the surface, takes place by diffusion, erosion, or a combination of both mechanisms in dependence on the solubility of the contained active ingredient. Although hydrophilic matrix tablets have become a well-tried and widely used dosage form with retarded effects, their research continues and new auxiliary substances and their combinations are being tested. The present paper reviews the knowledge published in this field in recent years.

        Key words: matrix tablets – hydrophilic polymers – modified drug release