title: Non-impactor-based methods for sizing of aerosols emitted from orally inhaled and nasal drug products (OINDPs).
abstract: The purpose of this article is to review non-impactor-based methods for measuring particle size distributions of orally inhaled and nasal pharmaceutical aerosols. The assessment of the size distributions of sprays and aerosols from orally inhaled and nasal drug products by methods not involving multi-stage cascade impaction may offer significant potential advantages in terms of labor savings and reducing the risk for operator-related errors associated with complex-to-undertake impactor-based methods. Indeed, in the case of nasal spray products, cascade impaction is inappropriate and alternative, and preferably non-invasive methods must be sought that minimize size-related bias associated with the measurement process for these relatively large droplets. This review highlights the options that are available to those involved with product quality assessments, providing guidance on relative strengths and weaknesses, as well as highlighting precautions that should be observed to minimize bias. The advent of Raman chemical imaging, which enables an estimate to be made of the proportion of each particle comprising active pharmaceutical ingredient(s) (APIs), necessitates a re-think about the value of classical microscopy image analysis as now being capable of providing API-relevant information from collected aerosols and sprays.
authors.affiliation: Trudell Medical International, London, Ontario, Canada.
authors.forename: Jolyon
authors.initials: J
authors.lastname: Mitchell
authors.forename: Richard
authors.initials: R
authors.lastname: Bauer
authors.forename: Svetlana
authors.initials: S
authors.lastname: Lyapustina
authors.forename: Terrence
authors.initials: T
authors.lastname: Tougas
authors.forename: Volker
authors.initials: V
authors.lastname: Glaab
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols / Q000737:chemistry*; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing / Q000295:instrumentation; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D004364:Pharmaceutical Preparations / Q000032:analysis*; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation*; D013535:Suspensions; D013678:Technology, Pharmaceutical / Q000295:instrumentation / Q000379:methods*
chemical_list: D000336:Aerosols; D004364:Pharmaceutical Preparations; D013535:Suspensions