EP1289589A2 — Medicament dispensing device with a multimaterial diaphragm bounding a pneumatic force chamber

USPTO Abstract

A metered dose inhaler for use with a pressurized aerosol container (25) which is preferably breath-actuated. A preload (460) is applied to the internal aerosol valve by an amount sufficient to result in a dose release, but this is prevented by the application of a pneumatic resisting force. The inhaler comprises a release device (520) which, upon actuation, releases the resisting force and allows the preload to actuate the aerosol valve. A metered dose of medicament is then released for inhalation by the patient. The pneumatic resisting force is established by a negative pressure region (600) defined in part by a diaphragm (440). The diaphragm (440) includes a central disk (441) of a first, relatively high stiffness material 'A' and a peripheral ring, coupled by a flexure of a second, relatively low stiffness material 'B'.