Prefilming atomizer

• US 8,616,464 B2
• Filed: 06/08/2011
• Issued: 12/31/2013
• Est. Priority Date: 12/30/2002
• Status: Active Grant

• Current Assignee: Novartis Ag
• Original Assignee: Novartis Ag
• Inventors: Nasiatka, James, Snyder, Herman E, Varga, Christopher M
• Primary Examiner(s): BOECKMANN, JASON J
• Application Number:
  US13/155,546
• Publication Number:
  US 20110297755A1
• Time in Patent Office: 937 Days
• Field of Search: 239/421, 239/426, 239/433, 239/434, 239/301, 239/418, 239/419.3, 239/422, 239/423, 239/425, 239/434.5, 239/293, 239/296, 239/400, 239413-4165, 239429-431, 239543-545, 239/8
• US Class Current: 239/8
• 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 for producing particles comprising:

providing an atomizer comprising;

a first annular channel for a liquid flow, wherein said first annular channel comprises a constriction having a diameter less than 0.51 mm for spreading a liquid into a thin film in the channel; and

a first circular gas flow channel and a second annular channel for an atomizing gas flow, wherein said first and second annular channels are concentric, wherein said first annular channel is intermediate to the first circular gas flow channel and the second annular channel, and wherein said first circular gas flow channel and said second annular channel are positioned so that the atomizing gas impinges the liquid thin film to produce droplets at an impingement point downstream from a contact point between the liquid thin film and gas from the second annular channel;

a third gas flow channel in fluid communication with and perpendicular to said first circular gas flow channel at the impingement point, wherein a flow of gas exiting the third gas flow channel impinges the liquid thin film;

providing a drying chamber to dry the droplets to produce particles;

providing a collector to collect the dried particles; and

atomizing a liquid feedstock with the atomizer, drying the droplets produced thereby with the drying chamber, and collecting the dried particles with the collector.

2. The method of claim 1, wherein the dried particles have a rugosity above 2.

3. The method of claim 1, wherein the dried particles have a density below 0.5 g/cm³.

4. The method of claim 1, wherein the dried particles have a mass median diameter less than 20 μ

m.

5. The method of claim 1, wherein the liquid feedstock comprises an active pharmaceutical agent and at least one excipient.

6. The method of claim 5, wherein the excipient has a glass transition temperature above 35°

C.