Portable drug delivery device including a detachable and replaceable administration or dosing element

An apparatus for transdermally delivering a drug formulation and stopping dosing or delivery in an automatic, controllable manner, comprising:

• (a) an active assembly comprising a controller;
• (b) a passive assembly adapted for mechanically coupling and decoupling with the active assembly, the passive assembly comprising:
• (i) a dispensing reservoir containing the drug formulation;
• and
• (ii) a delivery element comprising an administration reservoir and a membrane in fluid communication with the administration reservoir, the membrane being permeable to an active substance in the drug formulation;
• (c) a dispensing mechanism comprising:
• (i) an active portion in the active assembly providing a motive force to draw the drug formulation from the dispensing reservoir to the administration reservoir;
• and
• (ii) a passive portion in the passive assembly proximate to the active portion and defining a feed chamber through which the drug formulation flows from the dispensing reservoir;
• and
• (d) a stopping means for stopping dosing or slowing delivery by removing the drug or a solvent of the drug in the drug formulation from the administration reservoir, wherein the stopping means utilizes gas, air, fluid, or a combination thereof, which functions to flush the solvent, drug, or a combination thereof from the administration reservoir, and wherein the stopping means does not require removal of the apparatus from an application site during the flushing process.