EP1294420A2 — Pre-metered dose magazine for breath-actuated dry powder inhaler

USPTO Abstract

A pre-metered dose assembly for consistently supplying precise doses of medicament is provided for a breath-actuated dry powder inhaler. The assembly includes a cap defining a dry powder delivery passageway for providing air to dry powder supply port of a swirl chamber of a breath-actuated dry powder inhaler, and a magazine including a plurality of reservoirs for holding pre-metered doses of dry powder. One of the magazine and the cap is movable with respect to the other of the magazine and the cap for sequentially positioning the reservoirs within the delivery passageway of the cap. A breath-induced low pressure at an outlet port of the swirl chamber of the inhaler causes an air flow through the dry powder delivery passageway of the assembly and into the dry powder supply port of the swirl chamber that entrains dry powder from the reservoir positioned in the passageway for inhalation by a patient using the inhaler. The present disclosure also provides a breath-actuated dry powder inhaler including the pre-metered dose assembly in combination with a de-agglomerator for breaking up aggregates and micronizing particles of dry powder prior to inhalation of the powder by a patient.