Wearable injector with sterile adhesive patch

A method of preparing a drug delivery device for use, the method comprising:

• providing an adhesive patch, the adhesive patch including an area contained within an outer perimeter, the area having an upper surface, a lower surface, and an edge surface at the outer perimeter between the upper surface and the lower surface, a bacteria impermeable lower liner on the lower surface, and a bacteria impermeable sterility margin surrounding the edge surface;
• providing a sub-assembly of a drug delivery device comprising an insertion mechanism;
• adhering the upper surface of the adhesive patch to the drug delivery device or the sub-assembly of the drug delivery device.