title: Product Quality Research Institute evaluation of cascade impactor profiles of pharmaceutical aerosols, part 1: background for a statistical method.
abstract: The purpose of this article is 2-fold: (1) to document in the public domain the considerations that led to the development of a regulatory statistical test for comparison of aerodynamic particle size distribution (APSD) of aerosolized drug formulations, which was proposed in a US Food and Drug Administration (FDA) draft guidance for industry; and (2) to explain the background and process for evaluation of that test through a working group involving scientists from the FDA, industry, academia, and the US Pharmacopeia, under the umbrella of the Product Quality Research Institute (PQRI). The article and the referenced additional statistical information posted on the PQRI Web site explain the reasoning and methods used in the development of the APSD test, which is one of the key tests required for demonstrating in vitro equivalence of orally inhaled and nasal aerosol drug products. The article also describes the process by which stakeholders with different perspectives have worked collaboratively to evaluate properties of the test by drawing on statistical models, historical and practical information, and scientific reasoning. Overall, this article provides background information to accompany the companion article's discussion of the study's methods and results.
authors.affiliation: Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Rockville, MD, USA.
authors.forename: Wallace P
authors.initials: WP
authors.lastname: Adams
authors.forename: David
authors.initials: D
authors.lastname: Christopher
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Lee
authors.forename: Beth
authors.initials: B
authors.lastname: Morgan
authors.forename: Ziqing
authors.initials: Z
authors.lastname: Pan
authors.forename: Gur Jai Pal
authors.initials: GJ
authors.lastname: Singh
authors.forename: Yi
authors.initials: Y
authors.lastname: Tsong
authors.forename: Svetlana
authors.initials: S
authors.lastname: Lyapustina
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D003627:Data Interpretation, Statistical; D017277:Drug Approval / Q000379:methods; D004353:Drug Evaluation, Preclinical / Q000379:methods / Q000592:standards*; D017408:Guidelines as Topic; D008422:Materials Testing / Q000379:methods* / Q000592:standards*; D010316:Particle Size; D011785:Quality Assurance, Health Care / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D000336:Aerosols