Dosage forms comprising formulations of sparingly water-soluble active ingredients in a polymer matrix composed of polyether copolymers, said polyether copolymers being obtained by free-radically initiated polymerization of a mixture of 30 to 80% by weight of N-vinyllactam, 10 to 50% by weight of vinyl acetate and 10 to 50% by weight of a polyether, and of at least one surfactant, in which the sparingly water-soluble active ingredient is present in amorphous form in the polymer matrix.
