The present invention provides a manifold for receiving fluid tubes in a bulk compounder. In its simplest form, the manifold includes a plurality of inlets, each inlet defining an opening to a respective fluid passageway, and each passageway contains a check-valve. Included in this manifold is an outlet in fluid communication with the fluid passageways and an inlet port which is coaxial with the outlet. The coaxial inlet port contains a check-valve. Included as a part of the present invention is a cannula adapted for use with the manifold of the present invention, tube sets for use with the manifold of the present invention, and a method of minimizing error in filling a bag using a manifold in accordance with the present invention.