US Patent 7335155 Unitary formulation delivery device

An apparatus for delivering a formulation into a body in integer amounts includesa cannula with an insertion end for insertion into the body. The cannula includes a channel such as a tube to store the formulation. A rod is inserted into an end of the cannula opposite the insertion end; the rod has one end to contact the formulation and another end. The actuator controllably moves the rod through the tube of the cannula to deliver the formulation through the insertion end of the cannula.