Various aspects of the subject disclosure relate to a compounder system having a cartridge that includes fluid pathways controllable by valves of the cartridge. A pump component within the cartridge is actuable to move fluid through the controllable fluid pathways. The cartridge includes a needle extending from a cartridge body and fluidly coupled to at least one of the controllable fluid pathways. The cartridge includes a vacuum bellows that surrounds the needle when the bellows is in an extended configuration. The vacuum bellows is compressible to expose the needle and generates a vacuum condition within the bellows when the bellows is extended from a compressed configuration to the extended configuration. The needle may be a dual-lumen plastic needle.
