Devices, such as medical devices, are provided which include a body portion having at least one reservoir which has two or more openings, the two or more openings being defined in part by a reservoir cap support; reservoir contents, such as a drug formulation or sensor, disposed inside the reservoir; and a reservoir cap which closes off the two or more reservoir openings. The reservoir cap, which can be ruptured, controls release or exposure of the reservoir contents. In one embodiment, the device is an implantable medical device and provides for the controlled release of drug or exposure of a sensor.