NAVETTA in Action: In Vitro Simulation of Budesonide DPI Delivery and Efficacy

Gitte Slingers¹, An Jacobs¹, Jo van Laer¹, Magdalena Weiss², Lisa Kleon³, Benjamin Punz³, Martin Himly³, Sylvie Remy¹, Evelien Frijns¹ & Sandra Verstraelen¹

¹Flemish Institute for Technological Research (VITO), Environmental Intelligence Unit, Boeretang 200, Mol 2400, Belgium

²Helmholtz Munich, Lung Health and Immunity, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany

³Paris Lodron University Salzburg (PLUS), Dept. Biosciences & Medical Biology, Hellbrunnerstrasse 34, Salzburg 5020, Austria

Summary

This study explores the use of the NAVETTA air-liquid interface (ALI) exposure system in combination with the PreciseInhale^® aerosol generator to evaluate the anti-inflammatory effect of budesonide delivered via dry powder inhaler (DPI). The primary aim was to establish a reliable in vitro setup for testing inhaled pharmaceutical aerosols under physiologically relevant conditions. Symbicort^® Turbohaler^® DPI, containing active ingredients budesonide and formoterol, was aerosolized using the PreciseInhale^® system, producing a respirable aerosol with mass median aerodynamic diameter (MMAD) of 3.43 ±1.05µm, well within the optimal range for effective pulmonary deposition. The aerosol was subsequently delivered to pIL8-luc A549 reporter cells cultured at the ALI in the inverted configuration within the NAVETTA system, with or without tumor necrosis factor (TNF)-α stimulation to induce an inflammatory response.

Both cell viability and interleukin (IL)-8 promoter activity were assessed post-exposure to evaluate the anti-inflammatory effect of budesonide. Results showed no decrease in cell viability following aerosol exposure, confirming the non-cytotoxic nature of the exposure conditions. Exposure to budesonide from the Symbicort^® Turbohaler^® DPI significantly suppressed IL-8 promoter activity in TNF-α-stimulated cells, demonstrating the expected anti-inflammatory response. Additionally, aerosol deposited dose across the four available NAVETTA positions where cells cultured on transwells are exposed to aerosol showed a consistent dose gradient, with higher budesonide deposition at the first two positions. These findings underscore the need for dose normalization to ensure accurate and reproducible interpretation of biological responses to aerosolized compounds.

This study highlights the NAVETTA system as an effective tool for aerosol exposure studies and demonstrates its potential for in vitro evaluation of pharmaceutical inhalers.