This invention provides a budesonide/formoterol dry powder inhaler (10) comprising: a reservoir (14) containing a dry powder medicament and an arrangement for delivering a metered dose of the medicament from the reservoir； a cyclone deagglomerator (10') for breaking up agglomerates of the dry powder medicament； a delivery passageway /34) for directing an inhalation-induced air flow through a mouthpiece (24), the delivery passageway extending to the metered dose of medicament, wherein the medicament comprises micronised formoterol fumarate, micronised budesonide and a lactose carrier, the lactose carrier having a particle size distribution of d10 = 20-65 µm, d50 = 80-120 pm, d90 = 130-180 µm and <；10 um = <；10%.
