A transdermal formulation and method of treatment includes providing an active pharmaceutical ingredient, a poly-isobutylene or silicone PSA, optionally, an oil, a crosslinked polyvinylpyrrolidone, and optionally, silicon dioxide, wherein said formulation is prepared on a backing in a three layer transdermal delivery system formulated to provide transdermal delivery and therapeutic levels for up to seven days and optionally with an overlay system required to show bioequivalence.
