Transdermal drug delivery device

A drug delivery device comprising:

• an upper housing portion attached to a lower housing portion;
• a microneedle assembly;
• the upper housing portion and the lower housing portion cooperatively defining a cavity and surrounding the microneedle assembly, the drug delivery device being configured such that the lower housing portion is dissociated from the microneedle assembly;
• a reservoir disposed within the cavity and being in fluid communication with the microneedle assembly;
• a plunger disposed within a central region of the drug delivery device;
• and
• a pushing element configured to move the drug delivery device from an un-actuated position to an actuated position,
• wherein in the un-actuated position
• 1) the plunger is vertically aligned with and positioned above the reservoir and the microneedle assembly, and
• 2) the microneedle assembly is recessed relative to a bottom surface of the lower housing portion and spaced from a user's skin, and
• wherein in the actuated position
• 1) the plunger is moved relative to the upper housing portion by the pushing element to apply a force against the reservoir to thereby move both the reservoir and the microneedle assembly downward such that the microneedle assembly is moved into direct contact with the user's skin, and
• 2) the plunger acts on the reservoir, after the microneedle assembly is moved into direct contact with the user's skin, to push a drug formulation from the reservoir to the microneedle assembly.

A drug delivery device comprising:

• a central region, an outer region surrounding the central region, and an intermediate region disposed between the central region and the outer region, the drug delivery device comprising:
• a microneedle assembly disposed within the central region of the drug delivery device;
• a reservoir disposed within the central region, wherein the reservoir contains a drug formulation, and wherein the reservoir is in selective fluid communication with the microneedle assembly;
• and
• a pushing element disposed above both the reservoir and the microneedle assembly within the central region, the pushing element being configured to provide a force having a downward component to move the microneedle assembly into engagement witha user's skin,
• wherein the reservoir is disposed between the microneedle assembly and the pushing element, and wherein the downward component of the force from the pushing element is transmitted through the reservoir to the microneedle assembly without increasing pressure of the drug formulation within the reservoir.