Prefilming atomizer

• US 20040140374A1
• Filed: 12/16/2003
• Published: 07/22/2004
• Est. Priority Date: 12/30/2002
• Status: Active Grant

• Current Assignee: Novartis Ag
• Original Assignee: Nektar Therapeutics Incorporated
• Inventors: Varga, Christopher M., Snyder, Herman E., Nasiatka, James
• Granted Patent: US 7,967,221 B2
• Time in Patent Office: Days
• US Class Current: 239/418
• CPC Class Codes: A61K 9/0073 Sprays or powders for inhalation; Aerolised or nebulised preparations generated by other means than thermal energy; nasal sprays A61K9/0043; inhalation of vapours of volatile or heated drugs, e.g. essential oils or nicotine, A61K9/007; devices A61M
• CPC Class Codes: A61K 9/1682 Processes
• CPC Class Codes: B05B 7/0416 with arrangements for mixing one gas and one liquid
• CPC Class Codes: B05B 7/0433 with one inner conduit of gas surrounded by an external conduit of liquid upstream the mixing chamber
• CPC Class Codes: B05B 7/0441 with one inner conduit of liquid surrounded by an external conduit of gas upstream the mixing chamber
• CPC Class Codes: B05B 7/0466 with means for deflecting the central liquid flow towards the peripheral gas flow
• CPC Class Codes: B05B 7/062 with only one liquid outlet and at least one gas outlet
• CPC Class Codes: B05B 7/065 an inner gas outlet being surrounded by an annular adjacent liquid outlet
• CPC Class Codes: B05B 7/067 the liquid outlet being annular
• CPC Class Codes: B05B 7/0807 to form intersecting jets
• CPC Class Codes: F23D 2900/11101 Pulverising gas flow impinging on fuel from pre-filming surface, e.g. lip atomizers

Abstract

A method of forming droplets comprises flowing a liquid through a channel; spreading the liquid into a thin film in the channel; and impinging the thin film with a flowing gas to atomize the liquid into droplets. The droplets may then be dried to produce dried particles, such as particles comprising a pharmaceutical active agent. The droplets formed by the disclosed process have improved size and/or size distribution characteristics.

Claims

1. A method of forming droplets, the method comprising:

flowing a liquid through a channel;

spreading the liquid into a thin film in the channel; and

impinging the thin film with a flowing gas to atomize the liquid into droplets having a diameter less than 35 micrometers.

2. A method according to claim 1 wherein the thickness of the thin film is less than 0.020 in.

3. A method according to claim 1 wherein the thickness of the thin film is less than 0.005 in.

4. A method according to claim 1 wherein the liquid comprises a pharmaceutical active agent.

5. A method according to claim 1 further comprising contacting the thin film with a second flowing gas.

6. A method according to claim 1 wherein the thin film is cylindrically shaped.

7. A method of forming droplets, the method comprising:

flowing a liquid through a channel;

spreading the liquid into a thin film; and

impinging the thin film with a flowing gas to atomize the liquid into droplets, the flowing gas impinging the thin film at a right angle.

8. A method according to claim 7 wherein the thickness of the thin film is less than 0.020 in.

9. A method according to claim 7 wherein the thickness of the thin film is less than 0.005 in.

10. A method according to claim 7 wherein the liquid comprises a pharmaceutical active agent.

11. A method according to claim 7 wherein the thin film is cylindrically shaped.

12. A method of forming a pharmaceutical formulation, the method comprising:

flowing a liquid through a channel, the liquid comprising a pharmaceutical active agent;

spreading the liquid into a thin film;

impinging the thin film with a flowing gas to atomize the liquid into droplets; and

drying the droplets to form particles comprising the active agent.

13. A method according to claim 12 wherein the particles have a mass median diameter less than 20 μ

m.

14. A method according to claim 12 wherein the particles have a mass median diameter less than 10 μ

m.

15. A method according to claim 12 wherein the active agent comprises insulin.

16. A pharmaceutical formulation produced by a method comprising:

flowing a liquid through a channel, the liquid comprising a pharmaceutical active agent;

spreading the liquid into a thin film;

impinging the thin film with a flowing gas to atomize the liquid into droplets; and

drying the droplets to form particles comprising the active agent.

17. An atomizer for forming droplets, the atomizer comprising:

a first channel through which a liquid may flow, the channel comprising a constriction for spreading the liquid into a thin film in the channel; and

a second channel though which an atomizing gas may flow, the second channel being positioned so that the atomizing gas impinges the liquid thin film in a manner which produces droplets having a diameter less than 35 micrometers.

18. An atomizer according to claim 17 wherein the constriction has a diameter less than 0.020 in.

19. An atomizer according to claim 17 wherein the constriction has a diameter less than 0.005 in.

20. An atomizer according to claim 17 further comprising a third channel through which a gas may flow.

21. An atomizer according to claim 17 wherein the first channel is shaped so that the thin film is cylindrically shaped.

22. An atomizer for forming droplets, the atomizer comprising:

a first channel through which a liquid may flow, the channel comprising a constriction for spreading the liquid into a thin film in the channel; and

a second channel though which an atomizing gas may flow, the second channel being positioned so that the atomizing gas impinges the liquid thin film at a right angle to produce droplets.

23. An atomizer according to claim 22 wherein the constriction has a diameter less than 0.020 in.

24. An atomizer according to claim 22 wherein the constriction has a diameter less than 0.005 in.

25. An atomizer according to claim 22 wherein the first channel is shaped so that the thin film is cylindrically shaped.

26. A spray drying system for forming a pharmaceutical formulation, the system comprising:

an atomizer, the atomizer comprising a first channel through which a liquid may flow, the channel comprising a constriction for spreading the liquid into a thin film in the channel, the atomizer further comprising a second channel though which an atomizing gas may flow, the second channel being positioned so that the atomizing gas impinges the liquid thin film to produce droplets;

a drying chamber to dry the droplets; and

a collector to collect particles dried in the chamber.