A research team from the Fraunhofer Institute for Toxicology and Experimental Medicine ITEM has achieved a major breakthrough in respiratory medicine by demonstrating that drug concentrations in human lungs can be measured directly through particles in exhaled breath. This revolutionary approach promises to transform the development and optimization of inhaled therapies by providing a non-invasive method to monitor drug distribution within the lungs.
Award-Winning Research Recognition
Prof. Dr. Jens Hohlfeld, Head of Airway Research at Fraunhofer ITEM, and Dr. Olaf Holz received the prestigious Willi Stahlhofen Award from the International Society for Aerosols in Medicine (ISAM) for their groundbreaking study. The award ceremony took place on June 24 at the ISAM Congress in Washington DC, USA, recognizing the scientific importance of this fundamental finding.
The award-winning publication, titled "Assessing Human Lung Pharmacokinetics Using Exhaled Breath Particles," was published in the Journal of Aerosol Medicine and Pulmonary Drug Delivery and presents a completely new approach to measuring how inhaled drugs distribute within the lung.
Clinical Study Methodology and Results
In the clinical study, healthy volunteers received either an inhaled or oral dose of the bronchodilator salbutamol. Researchers then collected exhaled breath particles (PEx) – tiny droplets released during exhalation when previously collapsed small airways reopen. The analysis revealed that following inhalation, these particles provided clear pharmacokinetic profiles with significantly higher drug concentrations compared to samples taken from the nose or blood.
The study provides compelling proof of concept that PEx samples can be used to non-invasively measure drug levels directly within the epithelial lining fluid of the lungs in a targeted and patient-friendly manner.
Scientific Foundation and Development
The breakthrough builds on decades of scientific groundwork. As early as 2005, Jens Hohlfeld and Olaf Holz had highlighted the limitations of conventional exhaled breath condensate (EBC) analysis as part of a European Respiratory Society task force. Their core message emphasized that to gain reliable insights into lung processes, particles in exhaled air must be specifically collected and thoroughly characterized, both physically and analytically.
Two major research tracks evolved from this insight: one was a DFG-funded project focused on the physical characterization of exhaled aerosols, including experiments in microgravity. The other was the technical development of a device for collecting PEx particles – an effort spearheaded by Swedish researcher Prof. Anna-Carin Olin at the University of Gothenburg. This device, now commercially available under the name PExA, has been used successfully for the first time in a pharmacokinetic study.
Clinical Implications
"I am truly honored that ISAM recognizes the scientific importance of this fundamental finding," said Prof. Jens Hohlfeld. This study marks a milestone in the development of non-invasive methods to determine drug distribution in the lungs – a critical step toward improving the precision and effectiveness of inhaled treatments.
The breakthrough has major implications for the targeted development and optimization of inhaled therapies, offering researchers and clinicians a new tool to better understand how medications behave within the respiratory system without requiring invasive procedures.
