In their work, the BREATH team at Fraunhofer ITEM demonstrated for the first time that epithelial lining fluid (ELF) from the lung can be obtained completely non-invasively using exhaled breath particles (PEx). In a randomized crossover design, six healthy volunteers inhaled 400 µg of salbutamol or ingested 8 mg orally; subsequently, PEx, nasal fluid, and plasma samples were collected and analyzed over a period of up to 315 minutes. After inhalation, full pharmacokinetic profiles could be generated from nearly all PEx samples, with concentrations significantly exceeding those in nasal secretions and plasma. In contrast, PEx levels after oral administration remained close to the detection limit.

“Exhaled particles give us a window into the lung’s pharmacokinetics – precise and patient-friendly. We now have a tool that can sustainably link research and clinical practice,” said Prof. Dr. Hohlfeld, who accepted the award on behalf of the team in Washington. The study represents an important proof of concept: for the first time, drug levels in the lung can be measured non-invasively, efficiently, and without burdening patients. This method paves the way for optimized therapies in diseases such as asthma, COPD, and cystic fibrosis, as well as for early evaluations of new drug formulations – all without invasive sampling.

The publication builds on decades of fundamental research. As early as 2005, Hohlfeld and Holz, as part of a European Respiratory Society task force, highlighted the limitations of conventional breath analysis methods (EBC) and called for targeted particle collection. This laid the foundation for two major research streams: the physical characterization of aerosols (including in microgravity) and the technical development of the collection device for PEx particles. The current study marks the first successful application of this instrument in a pharmacokinetic context.

BREATH warmly congratulates the entire author team on this achievement. We look forward to further advancing PEx technology in close collaboration with clinical partners – with the goal of promoting its broad application in both research and clinical care.

Text: BREATH/AB

Photo: © Fraunhofer ITEM