INHALATION DEVICE

An inhaler for administering powder by inhalation, including an inhaler body having two ends and a peripheral wall therebetween; an inhalation unit disposed in the inhaler body, the inhalation unit comprising an inhalation channel, the inhalation channel having an air inlet and an outlet; a dosing unit disposed in the inhaler body for providing a dose of powder to the inhalation channel such that a stream of air containing powder may be drawn from the outlet of the inhalation channel on inhalation by a user; a divider having a first surface bounded by a periphery and which substantially closes one end of the inhaler body; a mouthpiece attached to the periphery of the divider, the mouthpiece having a substantially radially directed flange which provides a second surface and which, together with the first surface, defines an air chamber; a first inlet for the air chamber provided in the first surface within the periphery of the divider and in fluid communication with the outlet of the inhalation channel; a second inlet for the air chamber disposed in the first surface within the periphery of the divider and adjacent the first inlet, a stream of supplementary air in use being drawn through the second inlet on inhalation by the user; and a discrete opening in peripheral wall of the inhaler body which is in fluid communication with the second inlet of the air chamber.