Measuring particle size distribution in pharmaceutical aerosols

• US 7,414,720 B2
• Filed: 10/23/2006
• Issued: 08/19/2008
• Est. Priority Date: 07/27/2001
• Status: Expired due to Term

• Current Assignee: Boehringer Ingelheim International GmbH (C.H. Boehringer Sohn AG & Co. KG)
• Original Assignee: Boehringer Ingelheim International GmbH (C.H. Boehringer Sohn AG & Co. KG)
• Inventors: Hochrainer, Dieter, Wachtel, Herbert, Hoelz, Hubert, Boeck, Georg, Ziegler, Jochen, Kreher, Christoph, Scheffler, Christian
• Primary Examiner(s): Punnoose; Roy M
• Application Number:
  US11/551,881
• Publication Number:
  US 20070122349A1
• Time in Patent Office: 666 Days
• Field of Search: 356/335, 356/336
• US Class Current: 356/336
• CPC Class Codes: G01N 15/0205 by optical means
• CPC Class Codes: G01N 15/0211 Investigating a scatter or diffraction pattern
• CPC Class Codes: G01N 15/0255 with mechanical, e.g. inertial, classification, and investigation of sorted collections with centrifuges G01N15/042
• CPC Class Codes: G01N 2015/0261 using impactors

Abstract

Disclosed herein are methods for measuring the particle size distribution of a pharmaceutical aerosol, including methods utilizing laser diffraction.

Claims

1. A method for measuring the particle size distribution of a pharmaceutical aerosol by the use of laser diffraction, comprising:

generating an aerosol utilizing an inhaler;

spraying the generated aerosol into pre conditioned air having a relative humidity of at least 80%;

analyzing particle size distribution in the sprayed aerosol embedded into the pre-conditioned air using laser diffraction.

2. The method according to claim 1, wherein the pharmaceutical aerosol is an aerosol of liquid droplets.

3. The method according to claim 2, wherein the relative humidity is at least 85%.

4. The method according to claim 2, wherein the relative humidity is at least 90%.