Solid dosage forms are obtained by mixing at least one polymeric binder, at least one active ingredient, and, where appropriate, conventional additives to form a plastic mixture, and shaping, using as polymeric binder a copolymer of an N-vinyllactam and a copolymerizable monomer having a hydrophobic radical. Dosage forms which show slow release of the active ingredient are obtained in a simple and low-cost manner.