Prefilter for prevention of clogging of a nozzle in the generation of an aerosol and prevention of administration of undesirable particles

摘要

A device, drug package and methodology for using such to generate an aerosol by moving a flowable formulation through a low resistance filter and then through a nozzle comprised of a porous membrane are disclosed. The package is comprised of a collapsible wall portion that forms a container for holding a liquid formulation which container has an opening covered by a cover portion comprising a nozzle. The membrane pores of the nozzle have a size in the range of 0.25 to 6 microns, preferably 0.5 to 6 microns. A low resistance filter, which is positioned between the flowable formulation and the nozzle, includes openings that are the same size as or smaller than the pores of the nozzle's porous membrane but includes the openings in an amount and density such that flowable formulation flows through the filter with less resistance than when the formulation moves through the porous membrane. Thus, the filter does not significantly increase the amount of pressure needed to aerosolize the formulation, prevents clogging of the porous membrane of the nozzle by any undesirable particles that may be in the formulation, prevents delivery of any such undesirable particles to the patient, and thereby improves the homogeneity of the aerosol formulation delivered to the patient, as well as the consistency and reproducibility of the aerosolized dose created.