An inhaler for delivering metered doses of powdered medicament, the inhaler having a plurality of compartments spaced in an array and each arranged to contain a metered dose of the medicament, a lever to displace the compartments one by one into line with an inhalation aperture that constitutes a mouthpiece, each compartment including inner and outer edges, the plurality of compartments being closed by a sealing layer, the inhaler further having a mechanism adapted to lift the sealing layer off the inner and outer edges of the compartment to open an air passageway defined by the compartment and the sealing layer so that, in use, on inhalation through the mouthpiece, air flow in the air flow passageway picks up and entrains the powder in the compartment to be drawn with the air out of the inhaler through the mouthpiece.
