Steps toward nebulization in-use studies to understand the stability of new biological entities

The need for novel biological drugs against respiratory diseases has been highlighted during the Coronavirus (COVID-19) pandemic. The use of inhalation presents challenges to drug product stability, which is especially true for delivery using nebulizers (jet versus mesh technologies). The late-stage process of drug development in the pharmaceutical industry requires the investigation of in-use stability. In-use studies generate data that are guided by the requirements of regulatory authorities for inclusion in the clinical trial application dossier. In this review, I introduce the initial aspects of in-use stability studies during the development of an aerosol formulation to deliver biologics with a nebulizer. Lessons learned from this experience can guide future development and planning for formulation, analytics, material compatibility, nebulization process, and clinical trial preparations.