Abstract: A method and drug delivery system are provided for transdermally administering a psychedelic active agent to a subject to provide continuous microdose plasma levels of the active agent or a metabolite thereof during an extended drug delivery time period. The transdermal drug delivery system comprises a drug reservoir that houses a formulation containing the active agent, a combination of a solubilizer-type permeation enhancer and a plasticizer-type permeation enhancer, and a pH stabilizing agent. The pH stabilizing agent brings the pH of the formulation, at the system-skin interface, and/or within the skin as the active agent is transported across the skin from the skin surface to the bloodstream, to within 25% of the pKa of the active agent. Formulations and methods of use are also provided.

Abstract: A drug delivery system is provided for transdermally administering a psychedelic active agent to a subject to provide continuous microdose plasma levels of the active agent or a metabolite thereof during an extended drug delivery time period. The transdermal drug delivery system comprises a drug reservoir that houses a formulation containing the active agent, a combination of a solubilizer-type permeation enhancer and a plasticizer-type permeation enhancer, and a pH stabilizing agent. The pH stabilizing agent brings the pH of the formulation, at the system-skin interface, and/or within the skin as the active agent is transported across the skin from the skin surface to the bloodstream, to within 25% of the pKa of the active agent. Formulations and methods of use are also provided.