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 μm, d90=130-180 μm and <；10 um=<；10%.
