Method and apparatus for dispersion of dry powder medicaments

Apparatus for aerosolizing a powder, said apparatus comprising:

• a feed tube having an inlet end, an outlet end, and a lumen defining an axial flow path therebetween;
• means for flowing at least one high pressure gas stream past said outlet end in a direction which converges with the axial flow path at an angle in the range from 12.5.degree. to 65.degree. and
• a diffuser tube extending from the outlet end of the feed tube and having a lumen coaxially aligned with the feed tube lumen, wherein the diameter of the diffuser tube lumen increases in a direction away from the outlet end of the feed tube.

An improved method for aerosolizing a powdered medicament, said method being of the type wherein the powder is entrained and suspended in a flowing gas stream, wherein the improvement comprises inserting an inlet end of the feed tube into a receptacle containing the powdered medicament and flowing a high pressure gas stream past an outlet end of the feed tube which is downstream from the inlet end to induce air flow from the receptacle, through the tube, and into the flowing gas stream, wherein the powdered medicament is entrained in the air flow through the tube and combined with the high pressure gas stream, wherein the powdered medicament passes through a diffuser tube which diverges in a direction away from the outlet end of the feed tube and wherein the gas stream is flowed past the outlet end at an acute angle as measured between the gas stream and the inlet end.

A method for aerosolizing a powder contained in a receptacle having an access surface, said method comprising:

• coupling a powder inlet end of a feed tube having a central axis with a penetration in the access surface;
• and
• flowing a high pressure gas stream past a portion of the feed tube that is spaced apart from the powder inlet, the gas stream converging with the portion at an acute angle as measured between the gas stream and the central axis at the inlet end, the angle being selected to provide a sufficient gas flow through the feed tube so that a predetermined amount of powder in the receptacle is fluidized, drawn axially through the tube, and dispersed in the high velocity gas stream to form an aerosol, the angle further being selected to create shear forces within the feed tube sufficient to beak down agglomerates within the powder.