A transdermal drug delivery system is provided that includes a drug-in-adhesive matrix layer and a backing layer. The matrix layer includes an active pharmaceutical ingredient, a cross-linked polyvinylpyrrolidone binder, a mesoporous silicon dioxide filler, and a pressure sensitive adhesive, while the backing layer forms an exterior facing-surface of the delivery system. The ratio of the mesoporous silicon dioxide filler to the cross-linked polyvinylpyrrolidone binder ranges from about 1:1 to about 1:8. As a result of the specific components of the matrix layer and the amounts in which they are utilized, the resulting delivery system, which can include a homogeneous dispersion of the active pharmaceutical ingredient in the formulation, is capable of delivering the active pharmaceutical ingredient over a period of up to about 7 days in a generally constant and controlled fashion. Further, the only layer that contemplates the use of an adhesive component is the drug-in-adhesive matrix layer.
