Implantable device for delivering drugs using a capillary orifice for low fluid flow rates

An implantable device (100) for delivering a drug comprising: a housing (105) A source of drug (108) contained within the housing (105) An orifice mechanism (200) in the housing (105) and communicating with the fuen like drug (108) comprising the orifice mechanism (200) i) an inner member (210) having a proximal end and a distal end; and ii) a winding (220) helically wound around the inner member. The drug (108) is carried by the orifice mechanism (200) and dispensed outside of the housing (108), wherein the winding (220) is wound on the inner member such that the winding and the inner member (210 ) define a first channel (230) having a passageway helically fuid following the curvature of the winding for carrying the drug therethrough having an inlet (234) at the proximal end of the winding (220) and an outlet (236) in winding the distal end (220).