Aerosol delivery of salbutamol and terbutaline via a CE-marked medical vaping device: aerosol characterization and transfer efficiency compared to nebulization

Pulmonary delivery of bronchodilators remains challenging due to dose variability and suboptimal deposition with conventional inhalers and nebulizers. Thermal aerosolization via vaping devices has emerged as a promising alternative for controlled and reproducible delivery of active pharmaceutical ingredients (APIs). This study evaluates a CE-marked medical-grade vaping device (BIKY Breathe) for pulmonary delivery of salbutamol sulfate and terbutaline sulfate, assessing aerosol performance, particle size, and transfer efficiency, with comparison to a standard pneumatic nebulizer (Cirrus™2). Aerosols were generated under standardized puffing conditions and analyzed using a Glass Twin Impinger (GTI) and a Next Generation Impactor (NGI). Four API concentrations were tested to determine respirable dose, mass median aerodynamic diameter (MMAD), and emitted-dose reproducibility. The Cirrus™2 nebulizer served as reference. The tested device produced aerosols with MMADs of 1.10 ± 0.10 µm (terbutaline) and 1.13 ± 0.14 µm (salbutamol) indicating suitability for deep-lung deposition. Average aerosol mass per puff was ∼ 6 mg for both APIs with low inter-puff variability. Terbutaline achieved a maximum transfer efficiency of ∼ 40% at 1.35-1.80 mg/mL, whereas salbutamol did not exceed 10%, likely due to physicochemical constraints. Compared with the Cirrus™2 nebulizer, the vaping device generated more efficient micron aerosols and provided higher reproducibility of respirable doses. Overall, the CE-marked device demonstrates robust and reproducible aerosolization of bronchodilators, with particle size appropriate for deep-lung delivery. Terbutaline shows strong translational potential, while salbutamol would benefit from further formulation optimization. These in vitro results support the use of medical-grade vaping devices as promising platforms for pulmonary delivery of conventional and novel APIs.