Transdermal therapeutic system for the transdermal administration of rotigotine containing an therapeutically effective amount of rotigotine base in a self-adhesive layer structure, comprising A) a backing layer, and B) a rotigotine-containing biphasic layer, the bi phasic layer having a) an outer phase having a composition comprising 75% to 100% of a polymer or a polymer mixture, and b) an inner phase having a composition comprising rotigotine base, wherein the inner phase forms dispersed deposits in the outer phase, and wherein the inner phase comprises i. rotigotine base, and ii. a polymer mixture comprising at least two hydrophilic polymers selected from at least two of the polymer groups: - polyvinylpyrrolidones having a K- Value of at least 80, or from 80 to 200, - polyvinylpyrrolidones having a K- Value of less than 80, or from 10 to 79, - copolymers of vinyl caprolactam, vinylacetate and ethylene glycol, - copolymers of vinylpyrrolidone and vinylacetate, - copolymers of ethylene and vinylacetate, - polyethylene glycols, - polypropylene glycols, - acrylic polymers, - modified celluloses, wherein the polymer mixture in the inner phase is present in an amount sufficient so that said rotigotine base forms a solid solution with the polymer mixture in the inner phase, and C) optionally an additional skin contact layer.
