Microdevice and method for transdermal delivery and sampling of active substances

A method of delivering an agent, or a combination of agents, for a medical condition to a mammal, comprising

• applying an applicator comprising a microdevice to cause the microdevice to contact an area of skin of the mammal to generate a prepared area of skin comprising a plurality of nanopores or nanochannels through the stratum corneum of the prepared area of skin and removing the applicator and microdevice from the skin immediately after the microdevice has penetrated the skin,
• applying a wet formulation comprising the agent to the area of skin being prepared either before or after the microdevice has generated the plurality of nanopores or nanochannels in the prepared area of skin,
• subsequently applying an occlusive layer over the agent and directly on the prepared area of skin such that the occlusive layer prevents air from coming into contact with the prepared area of skin following the removal of the applicator and microdevice from the skin, and
• causing an effective amount of agent to deliver to the patient through the nanopores or nanochannels in the stratum corneum at a rate percent penetration that is higher than the rate of percent penetration if no nanopores or nanochannels are present.