Drug delivery methods and systems

A two-part bioactive agent delivery system, the system comprising:

• a disposable part comprising
• an agent reservoir,
• a transdermal patch communicating with the agent reservoir and adapted to transdermally deliver the bioactive agent to a user, the transdermal patch having a bottom surface adapted to contact skin of the user and a top surface opposite the bottom surface, and
• a gas permeable membrane disposed over the top surface of the transdermal patch;
• a reusable part comprising a power source and control electronics, the control electronics being adapted to deliver bioactive agent dissolved in a solvent from the agent reservoir to the transdermal patch;
• a solvent removal element comprising a gap disposed between the disposable part and the reusable part to create a flow path for gaseous solvent to flow from the gas permeable membrane to ambient air around the bioactive agent delivery system, and
• wherein the gap is maintained with a spacer disposed between the disposable part and the reusable part.