The present invention provides a dry powder inhaler comprising: a reservoir containing a dry powder formulation and an arrangement for delivering a metered dose of the medicament from the reservoir； a cyclone deagglomerator for breaking up agglomerates of the dry powder medicament； and a delivery passageway for directing an inhalation-induced air flow through a mouthpiece, the delivery passageway extending to the metered dose of medicament, wherein the formulation comprises an inhalable β2-agonist having a particle size distribution of d10 <；1 μm, d50 = 1-3 μm, d90 = 3.5-6 μm and NLT 99% <；10 μm and a lactose carrier.本發明提供一種乾燥粉末吸入器，其包括：裝納乾燥粉末調配物之貯集槽及用於自該貯集槽傳遞計量劑量之藥劑之配置；用於粉碎乾燥粉末藥劑之聚結物之旋風解黏聚器；及用於導引吸入誘導的氣流通過吹嘴之傳遞通道，該傳遞通道係延伸至計量劑量之藥劑，其中該調配物包含具有d10<；1μm、d50=1至3μm、d90=3.5至6μm及NLT 99%<；10μm之粒度分佈之可吸入式β2-激動劑、及乳糖載體。
