Abstract A new portable device is described for administration of powdered drugs by inhalation. Powder contained in a standard hard gelatin capsule is induced to flow from the capsule into the air stream by a vibratory feed mechanism arising from a rotor driven by the inhaled air. The relationship between air flow rate, vibratory cycle, and powder emission was investigated, and the results indicate a good degree of coordination of dose administration with inhalation into the inspired air stream. The ability of the device to dispense size‐graded fractions of lactose, in the range of 4–400 μ, was investigated. Poor flow of the finest powders was demonstrated and can be overcome by use of a coarse flow aid.