Abstract: A housing is provided for insertion in an intravenous delivery system including a fluid source and a fluid conduit. The housing is adapted for receiving a beneficial agent to be mixed with fluid flowing through the fluid conduit. The beneficial agent is reconstituted within the housing, eliminating the need for manual reconstitution. The housing may comprise a separate receptacle and cartridge in which the receptacle is manufactured "in-line" in an administration set and the cartridge is adapted for receiving a beneficial agent. In one embodiment of the invention, the cartridge is a standard drug vial.