Claims for Patent: 6,681,768

Summary for Patent: 6,681,768

Title:	Powder formulation disintegrating system and method for dry powder inhalers
Abstract:	A disperser for dry powders which can be used with different dose systems, dose weights ranging from 2 to 25 mg and different types of powder formulation. In one embodiment, the disperser acts both as a de-agglomeration (disintegration; aerosolization) means and as an air classifier for especially adhesive mixtures. Only fine drug particles are emitted whereas the larger agglomerates and carrier crystals are retained by the disperser. Another embodiment enables time controlled release of carrier crystals in these mixtures. Yet another embodiment has optimized performance with spherical pellets, containing no carrier crystals. Other possible embodiments of the invention make it possible to control the total inhaler resistance and the powder deposition in the upper respiratory tract by means of the addition of a so-called sheath flow of clean air. Modifications also enable carrier retainment in the mouthpiece and elimination of the tangential flow component of the discharge cloud.
Inventor(s):	Haaije de Boer; Anne (Drachten, NL), Frijlink; Henderik Willem (Eelde, NL), Gjaltema; Doetie (Oosterwolde, NL), Goede; Joachim (Hanau, DE), Hagedoorn; Paul (Assen, NL)
Assignee:	Sofotec GmbH & Co. KG (Frankfurt am Main, DE)
Application Number:	10/177,433
Patent Claims:	1. A dry powder inhaler comprising: a circulation chamber wall, a top wall and a bottom wall together defining a circulation chamber having a central axis, a distance between said top and bottom walls defining a chamber height, said circulation chamber wall defining a circumference of said circulation chamber and a chamber diameter, said chamber height being less than said chamber diameter; a first supply channel defining a first opening in said circulation chamber wall, said first supply channel in communication with a powder supply region and wherein said first supply channel conveys air and powder to said circulation chamber, said first supply channel oriented to direct conveyed air and powder into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber; a plurality of second air supply channels each defining a second opening in said circulation chamber wall, said second openings and said first opening positioned substantially symmetrically about said central axis, each said second air supply channel in communication with a source of air wherein each said second air supply channel conveys substantially powder-free air to said circulation chamber, each said second air supply channel oriented to direct conveyed air into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber, said first supply channel and each of said second air supply channels oriented to convey air into said circulation chamber in a common rotational direction about said central axis whereby air and powder are conveyed within said circulation chamber in a generally circular flow pattern; a discharge channel positioned substantially coaxially with said circulation chamber, said discharge channel having a first end and an opposite second end, said discharge channel having a portion extending through said top wall, said first end defining an inlet positioned within said circulation chamber and between said bottom wall and said top wall, said discharge channel portion disposed within said circulation chamber having an outer perimeter spaced radially inwardly from said circulation chamber wall, said second end defining a discharge opening; and a third air supply channel in communication with a source of air wherein said third air supply channel conveys substantially powder-free air, said third air supply channel defining an outlet positioned coaxially with said second end wherein said outlet forms an annular opening surrounding an exterior surface of said discharge channel at said second end and whereby said third air supply channel supplies a sheath of powder-free air surrounding powder-laden air discharged from said second end. 2. The dry powder inhaler of claim 1 wherein said plurality of second air supply channels consists of seven second air supply channels. 3. The dry powder inhaler of claim 1 wherein said top wall further comprises a flange extending radially outwardly of said circulation chamber wall, said flange defining passages therethrough, said passages forming a portion of said third air supply channel. 4. The dry powder inhaler of claim 1 wherein said first opening and each of said second openings have a substantially rectangular shape. 5. The dry powder inhaler of claim 1 wherein said first opening and said second openings have a top edge positioned adjacent said top wall and have a bottom edge positioned approximately midway between said top wall and said bottom wall. 6. The dry powder inhaler of claim 5 wherein said discharge channel extends into said circulation chamber by a distance greater than one half said chamber height whereby said inlet is positioned closer to said bottom wall than to said top wall. 7. A dry powder inhaler comprising: a circulation chamber wall, a top wall and a bottom wall together defining a circulation chamber having a central axis, a distance between said top and bottom walls defining a chamber height, said circulation chamber wall defining a circumference of said circulation chamber and a chamber diameter, said chamber height being less than said chamber diameter; a first supply channel defining a first opening in said circulation chamber wall, said first supply channel in communication with a powder supply region and wherein said first supply channel conveys air and powder to said circulation chamber, said first supply channel oriented to direct conveyed air and powder into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber; at least one second air supply channel defining at least one second opening in said circulation chamber wall, said at least one second opening and said first opening positioned substantially symmetrically about said central axis, said at least one second air supply channel in communication with a source of air wherein said at least one second air supply channel conveys substantially powder-free air to said circulation chamber, said at least one second air supply channel oriented to direct conveyed air into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber, said first and second air supply channels oriented to convey air into said circulation chamber in a common rotational direction about said central axis whereby air and powder are conveyed within said circulation chamber in a generally circular flow pattern; a discharge channel positioned substantially coaxially with said circulation chamber, said discharge channel having a first end and an opposite second end, said first end defining an inlet in communication with said circulation chamber, said second end defining a discharge opening for discharging powder-laden air; and wherein said circulation chamber wall is defined by a plurality of wall segments, each of said wall segments being substantially planar and having a height extending from said bottom wall to said top wall, said plurality of wall segments comprising a plurality of long wall segments and a plurality of short wall segments, each of said long wall segments having a length no less than a first length and each of said short wall segments having a length no greater than a second length, said first length being greater than said second length, said long wall segments and said short wall segments being alternatively positioned along said circumference of said circulation chamber wherein one of said short wall segments is positioned at an angle to and, with respect to said circular flow pattern, downstream of each of said long wall segments. 8. The dry powder inhaler of claim 7 wherein each of said long wall segments is positioned at an approximately 135 degree angle to said short wall segment positioned downstream thereof. 9. The dry powder inhaler of claim 7 further comprising a third air supply channel in communication with a source of air wherein said third air supply channel conveys substantially powder-free air, said third air supply channel defining an outlet positioned coaxially with said second end wherein said outlet forms an annular opening surrounding an exterior surface of said discharge channel at said second end and whereby said third air supply channel supplies a sheath of powder-free air surrounding powder-laden air discharged from said second end. 10. The dry powder inhaler of claim 7 wherein said at least one second opening comprises 3 to 8 second openings positioned substantially symmetrically about said central axis and oriented to direct powder-free air into said circulation chamber in a direction substantially tangential to an interior surface of said circulation chamber wall and in said common rotational direction and wherein said plurality of long wall segments is equal in number to a total number of said second openings and said first opening, and said plurality of short wall segments is equal in number to said total number of said second openings and said first opening. 11. The dry powder inhaler of claim 10 wherein said at least one second opening consists of 3 second openings. 12. A dry powder inhaler comprising: a circulation chamber wall, a top wall and a bottom wall together defining a circulation chamber having a central axis, a distance between said top and bottom walls defining a chamber height, said circulation chamber wall defining a circumference of said circulation chamber and a chamber diameter, said chamber height being less than said chamber diameter; a first supply channel defining a first opening in said circulation chamber wall, said first supply channel in communication with a powder supply region and wherein said first supply channel conveys air and powder to said circulation chamber, said first supply channel oriented to direct conveyed air and powder into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber; a plurality of second air supply channels defining a plurality of second openings in said circulation chamber wall, said second openings and said first opening positioned substantially symmetrically about said central axis, said second air supply channels in communication with a source of air wherein said second air supply channels convey substantially powder-free air to said circulation chamber, each of said second air supply channels oriented to direct conveyed air into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber, said first supply channel and each of said second air supply channels oriented to convey air into said circulation chamber in a common rotational direction about said central axis whereby air and powder are conveyed within said circulation chamber in a generally circular flow pattern; a discharge channel positioned substantially coaxially with said circulation chamber, said discharge channel having a first end and an opposite second end, said first end defining an inlet in communication with said circulation chamber, said second end defining a discharge opening for discharging powder-laden air; and wherein said circulation chamber wall is defined by a plurality of wall segments, each of said wall segments being substantially planar and having a height extending from said bottom wall to said top wall, each of said wall segments positioned in pairs wherein each said pair comprises two intersecting wall segments forming an angle of approximately 135 degrees and said first opening and said second openings are positioned to separate each said pair of wall segments from an adjacent one of said pairs of wall segments. 13. The dry powder inhaler of claim 12 further comprising a third air supply channel in communication with a source of air wherein said third air supply channel conveys substantially powder-free air, said third air supply channel defining an outlet positioned coaxially with said second end wherein said outlet forms an annular opening surrounding an exterior surface of said discharge channel at said second end and whereby said third air supply channel supplies a sheath of powder-free air surrounding powder-laden air discharged from said second end. 14. The dry powder inhaler of claim 12 wherein said plurality of second openings comprises 3 to 8 second openings. 15. The dry powder inhaler of claim 14 wherein said plurality of second openings consists of 3 second openings. 16. A dry powder inhaler comprising: a circulation chamber wall, a top wall and a bottom wall together defining a circulation chamber having a central axis, a distance between said top and bottom walls defining a chamber height, said circulation chamber wall defining a circumference of said circulation chamber and a chamber diameter, said chamber height being less than said chamber diameter; a first supply channel defining a first opening in said circulation chamber wall, said first supply channel in communication with a powder supply region and wherein said first supply channel conveys air and powder to said circulation chamber, said first supply channel oriented to direct conveyed air and powder into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber; at least one second air supply channel defining a second opening in said circulation chamber wall, said second opening and said first opening positioned substantially symmetrically about said central axis, said second air supply channel in communication with a source of air wherein said second air supply channel conveys substantially powder-free air to said circulation chamber, said second air supply channel oriented to direct conveyed air into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber, said first supply channel and said second air supply channel oriented to convey air into said circulation chamber in a common rotational direction about said central axis whereby air and powder are conveyed within said circulation chamber in a substantially circular flow pattern; a discharge channel positioned substantially coaxially with said circulation chamber, said discharge channel having a first end and an opposite second end, said discharge channel extending through said top wall, said first end defining an inlet positioned within said circulation chamber and between said bottom wall and said top wall, said discharge channel disposed within said circulation chamber having an outer perimeter spaced radially inwardly from said chamber wall, said second end defining a discharge opening; and a third air supply channel in communication with a source of air wherein said third air supply channel conveys substantially powder-free air, said third air supply channel defining an outlet positioned coaxially with said second end wherein said outlet forms an annular opening surrounding an exterior surface of said discharge channel at said second end and whereby said third air supply channel supplies a sheath of powder-free air surrounding powder-laden air discharged from said second end; and wherein said top wall defines a flange extending radially outwardly of said circulation chamber wall, said flange defining passages therethrough, said passages forming a portion of said third air supply channel. 17. A dry powder inhaler comprising: a circulation chamber wall, a top wall and a bottom wall together defining a circulation chamber having a central axis, a distance between said top and bottom walls defining a chamber height, said circulation chamber wall defining a circumference of said circulation chamber and a chamber diameter, said chamber height being less than said chamber diameter; a first supply channel defining a first opening in said circulation chamber wall, said first supply channel in communication with a powder supply region and wherein said first supply channel conveys air and powder to said circulation chamber, said first supply channel oriented to direct conveyed air and powder into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber; at least one second air supply channel defining at least one second opening in said circulation chamber wall, said at least one second opening and said first opening positioned substantially symmetrically about said central axis, said at least one second air supply channel in communication with a source of air wherein said at least one second air supply channel conveys substantially powder-free air to said circulation chamber, said at least one second air supply channel oriented to direct conveyed air into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber, said first supply channel and said second air supply channel oriented to convey air into said circulation chamber in a common rotational direction about said central axis whereby air and powder are conveyed within said circulation chamber in a substantially circular flow pattern; a discharge channel positioned substantially coaxially with said circulation chamber, said discharge channel extending from a first end to an opposite second end and having an interior surface defining a substantially circular cross sectional shape, said discharge channel having a portion extending through said top wall, said first end defining an inlet positioned within said circulation chamber and between said bottom wall and said top wall, said portion of said discharge channel disposed within said circulation chamber having an outer perimeter spaced radially inwardly from said chamber wall, said second end defining a discharge opening; and a baffle member positioned in said discharge channel to disrupt helical flow of particles through said discharge channel and direct particles in a direction substantially parallel to said central axis. 18. The dry powder inhaler of claim 17 wherein said baffle member comprises a plurality of ridges projecting radially inwardly from said interior surface and extending parallel to said central axis, said interior surface defining a discharge diameter and said ridges projecting inwardly a distance less than said discharge diameter. 19. The dry powder inhaler of claim 17 wherein said baffle member comprises a plurality of baffle frameworks extending between diametrically opposite sides of said interior surface and each of said frameworks being positioned at spaced locations along said central axis. 20. The dry powder inhaler of claim 19 wherein said frameworks are cross-shaped. 21. The dry powder inhaler of claim 17 further comprising a third air supply channel in communication with a source of air wherein said third air supply channel conveys substantially powder-free air, said third air supply channel defining an outlet positioned coaxially with said second end wherein said outlet forms an annular opening surrounding an exterior surface of said discharge channel at said second end and whereby said third air supply channel supplies a sheath of powder-free air surrounding powder-laden air discharged from said second end. 22. A modular dry powder inhaler system comprising: an inhaler body having a circulation chamber wall and a bottom wall defining a portion of a circulation chamber having a central axis, said circulation chamber wall defining a circumference of said circulation chamber; a first supply channel defining a first opening in said circulation chamber wall, said first supply channel in communication with a powder supply region and wherein said first supply channel conveys air and powder to said circulation chamber; said first supply channel oriented to direct conveyed air and powder into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber; at least one second air supply channel defining at least one second opening in said circulation chamber wall, said at least one second opening and said first opening positioned substantially symmetrically about said central axis, said at least one second air supply channel in communication with a source of air wherein said at least one second air supply channel conveys substantially powder-free air to said circulation chamber, said at least one second air supply channel oriented to direct conveyed air into said circulation chamber in a direction substantially tangential to said circumference of said circulation chamber, said first and second air supply channels oriented to convey air into said circulation chamber in a common rotational direction about said central axis whereby air and powder are conveyed within said circulation chamber in a substantially circular flow pattern; a plurality of top plates, each of said top plates being removably mountable to said inhaler body and, when mounted to said inhaler body, forming a top wall of said circulation chamber wherein a distance between said top and bottom walls defines a chamber height and said circulation chamber wall defines a chamber diameter, said chamber height being less than said chamber diameter, each said top plate further defining a discharge channel positionable substantially coaxially with said circulation chamber, each said discharge channel having a first end and an opposite second end, said first ends defining an inlet opening in communication with said circulation chamber and said second ends defining a discharge opening for discharging powder-laden air when mounted to said inhaler body, said plurality of top plates having a plurality of different configurations whereby a selected one of said top plates can be attached to said inhaler housing based upon user requirements. 23. The modular dry powder inhaler system of claim 22 further comprising a mouthpiece removably mountable to said inhaler body, attachment of said mouthpiece to said inhaler body securing said selected one of said top plates to said inhaler body, said mouthpiece defining a third air supply channel in communication with a source of air wherein said third air supply channel conveys substantially powder-free air, said third air supply channel defining an outlet positioned coaxially with said second end of said selected top plate wherein said outlet forms an annular opening surrounding an exterior surface of said discharge channel at said second end of said selected top plate and whereby said third air supply channel supplies a sheath of powder-free air surrounding the powder-laden air discharged from said second end of said selected top plate. 24. The modular dry powder inhaler system of claim 23 wherein each of said plurality of top plates defines a flange extending radially outwardly of said circulation chamber wall, said flanges defining passages therethrough, said passages of said selected top plate forming a portion of said third air supply channel. 25. The modular dry powder inhaler system of claim 23 wherein said plurality of top plates each define a discharge channel wherein each of said second ends have a common discharge opening diameter and wherein said first ends define a plurality of different inlet opening diameters. 26. The modular dry powder inhaler system of claim 22 wherein at least one of said top plates has a discharge channel defining a substantially circular cross sectional shape and further comprises a baffle member positioned in said discharge channel to disrupt helical flow of particles through said discharge channel and direct particles in a direction substantially parallel to said central axis when mounted to said inhaler body.