Various embodiments of the present invention are directed to limiting a presence of air bubbles in fluidic media in a reservoir. Air passages may allow air to escape from fluidic media in a reservoir. Membranes may allow for trapping air bubbles in fluidic media before fluidic media enters a reservoir. A membrane may allow air to flow from a first reservoir containing fluidic media to a second reservoir while plunger heads within each of the reservoirs are moved within the reservoirs. An inner reservoir with a membrane may be moveable within an outer reservoir to allow air to move from the outer reservoir to the inner reservoir. An inner reservoir containing pressurized gas may allow fluidic media to be transferred to an outer reservoir.