A system and method for a patch-like, self-contained multi-component substance infusion device which provides one or more substantially hidden patient needles which can be placed in fluid communication with a fluid reservoir assembly that includes a rigid bladder portion used in conjunction with a non-distensible bladder film, such as a metallized film. The device can be attached to a skin surface via an adhesive contact and a pressurization system provides a pressure to the contents of a fluid reservoir assembly. Improvements to dry powdered formulations for reconstitution for preferred use in the device are also disclosed.