Entraining powder in an airflow

Abstract

A device for inhalation of at least one air stream carrying a dose of medicament powder. The device comprises a powder-containing cavity which opens into a flow passage. The flow passage is arranged to direct an inhalation air flow across the cavity opening. A circulating flow is thereby induced in the cavity by the phenomenon of shear driven cavity flow. Powder is entrained in the circulating flow and deaggregated before exiting the cavity and becoming entrained in the flow of air along the flow passage.

1 . A dry powder inhaler device for dispensing an air stream carrying a dose of medicament powder, the device defining a flow passage and a powder storage cavity having a cavity opening, wherein the cavity opening is disposed in a wall of the flow passage with the flow passage arranged to direct a flow of air across the cavity opening, wherein the cavity opening has a length in the flow direction, and has a depth, the cavity opening length being between 50% and 150% of the cavity depth, and at least 80% of a maximum length of the cavity in the flow direction, and wherein the flow passage has a maximum height immediately adjacent the cavity, the maximum height being between 0.5 mm and 4 mm. 
     
     
         2 .- 35 . (canceled)