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
Estimating the term…
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
In a process for determining the size distribution of the particles contained in an aerosol of a pharmaceutical formulation, the improvement which comprises:
- preparing a carrier medium which is saturated with a conditioning agent according to a given degree of saturation,
- mixing the conditioned carrier medium with a pharmaceutical formulation to produce a conditioned aerosol,
- introducing the aerosol into at least one measuring cell;
- and
- measuring the conditioned aerosol in the measuring cell to determine the particle size distribution of the aerosol.
Dependencies are inferred from the claim text.