Abstract: A device (10) for generating a pulsatile fluid drug flow comprises a housing (11) containing an expandable-contractible chamber (12) having an inlet (14) and an outlet (15), a valve (16) associated with the outlet (15) which is actuated by the expansion and contraction of the chamber (12), and means (13, 23) for biasing the chamber (12) to its contracted state. When the inlet (14) is connected to a pressurised fluid drug supply the chamber (12) is expanded by the drug, and this expansion of the chamber (12) actuates the valve (16) to open, thereby allowing release of the drug from the chamber (12), following which the chamber (12) contracts under the influence of the biasing means (13, 23), this contraction in turn actuating the valve (16) to close thereby allowing the chamber (12) to refill. By this mechanism, a constant supply of liquid, such as from an osmotic or elastomeric drug delivery pump, can be converted to a pulsatile flow, which may provide a more suitable delivery of certain drugs.

Abstract: A subcutaneous drug delivery device having a housing having an internal reservoir in communication with a drug delivery needle via a fluid path. An expandable chamber disposed adjacent to the reservoir forces drug from the reservoir to the needle when supplied with a gas. A flow regulating chamber, in communication with the fluid path, is capable of volumetric changes in response to temperature and/or pressure changes. An increase in the volume of the flow regulating chamber increases flow resistance to the needle and thereby counteracts the corresponding increase in delivery rate resulting from the expansion of the expandable chamber due to the same volumetric changes in response to temperature and/or pressure. The device also includes an improved filling system that enables the reservoir within the device to be filled with drug from a source without regard to filling position and with a decreased risk of injury from needles.