DRY POWDER INHALERS

摘要

A dry powder inhaler comprises a reservoir (68) of medicament powder, a dispensing chamber for receiving a charge of powder to be dispensed having a floor upon which said charge lies prior to inhalation formed by the top of a disc (40) rotatable beneath the reservoir to draw therefrom a dose of said powder in a recess (42), a horn shaped air inlet passage (54) having at its outlet end a nozzle protruding into said dispensing chamber directed toward said floor thereof and an inhalation passage (62) exiting from said chamber through which said powder may be inhaled entrained in air drawn into the inhaler through said air inlet passage. The air inlet passage (54) is the principal or sole route for air to enter said dispensing chamber in use. The inhalation passage has an inlet at said chamber and an outlet through which said powder may be inhaled and comprises a first upstream portion (64) having a roof and a floor both of which rise progressively with respect to a straight line drawn from the centre of said inlet to the centre of said outlet and a second portion (66) having a roof and a floor both of which fall progressively with respect to said line in the downstream direction.