Process for determining the particle size distribution of an aerosol and apparatus for carrying out such a process
AssigneeBoehringer Ingelheim International GmbH
InventorsDieter Hochrainer, Georg Boeck, Hubert Hoelz, Christian Scheffler, Christoph Kreher
Life of this patent
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Abstract
The measurement of the particle size distribution of an aerosol is of crucial importance in pharmaceutical development. A prerequisite for this is a valid method, e.g. the cascade impactor method described in the pharmacopoeias. It requires measurement of the active substance concentration in order to determine the particle size distribution. The invention provides a process which makes it possible to measure the size of aerosol droplets containing pharmaceutical substances which are unstable in the event of changes in the pH.
Claims11
An apparatus for determining the size distribution of particles contained in an aerosol of a pharmaceutical formulation, comprising:
- a conditioning device (24) for saturating a carrier medium with a conditioning agent according to a given saturation level to produce a conditioned carrier medium,
- a metering device (26) for metering a pharmaceutical formulation,
- a mixing chamber (25) for mixing the conditioned carrier medium and the metered pharmaceutical formulation to produce a conditioned aerosol of pharmaceutical formulation, and
- at least one measuring cell (23) into which the conditioned aerosol of pharmaceutical formulation is introduced in order to carry out a measurement of the particle size distribution of the aerosol.
Dependencies are inferred from the claim text.