Abstract: A dry powder inhaler comprises a disc-shaped assembly (14) having cavities (16) filled with medicament powder for inhalation. The assembly is rotatably mounted in a housing (6, 8) on which is mounted a rotatable external casing (11, 12). A mouthpiece (10) is movably mounted on the housing (6, 8) allowing it to be brought into and out of engagement with the edge of the disc (14) whereby the mouthpiece acts as a brake to prevent or permit rotational movement of the disc (14). The inhaler is opened by rotating the housing with respect to the casing (11, 12) to expose the mouthpiece (10). As the inhaler is opened and closed, cam followers (105) on the mouthpiece move along cam tracks (109) in the casing (11, 12), causing the mouthpiece to move against or away from the disc (14). A gap is defined between the disc and mouthpiece to allow a flow of bypass air to enter the mouthpiece.

Abstract: A dry powder inhaler (2) comprises a housing (6, 8) including a mouthpiece (10) and a cover (11, 12) movably mounted to the housing (6, 8). The cover (11, 12) is movable between an open configuration of the inhaler (2) in which the mouthpiece (10) is exposed for use and a closed configuration of the inhaler (2) in which the mouthpiece (10) is enclosed. In the open position, the cover (11, 12) at least partly defines an inlet aperture (71) to an inhalation air flow path leading through the inhaler (2) and communicating with the mouthpiece (10). The inlet aperture (71) is positioned in such a way that makes it difficult for a user to obstruct it when using the inhaler (2). Preferably, in the closed position, the mouthpiece (10) is received into the inlet aperture (71) to protect the mouthpiece (10) when the inhaler (2) is stored.