技術論文とプレゼンテーション

Dry powder inhalers (DPIs) are widely used in the treatment of asthma and chronic obstructive pulmonary disease (COPD). These therapies critically depend on the powder aerosolization and deagglomeration to reach deep lung deposition (respirable sizes are generally defined as < 5 µm in diameter).

The use of DPIs is now expanding to the delivery of larger payloads of lower-potency formulations. This requires the development of new deagglomeration engines ensuring efficient drug delivery to patients. The concept device O1 was developed to address these challenges: it uses an innovative deagglomeration engine that involves the free motion of a cruciform-shaped ball encapsulated in a three-inlet cyclonic chamber.

The impact of the presence of the ball on the flow and its interaction with particles was investigated using COMSOL Multiphysics. The modelling approach was supported by and validated against high-speed imaging and aerosol testing, showing good agreement. The flow in the cyclonic chamber is computed using the CFD module with a stationary turbulent k-ε model, using a quasi-static approximation justified by direct observations of the flow. Particle trajectories and associated statistics were computed using the Particle Tracing module in parametric studies varying the particle diameter.

The modelling and investigations demonstrate that the presence of the free cruciform ball enhances particle recovery at the mouthpiece, with increases of 60 % or more for particles of diameter ≥ 2 µm. This allows a sustained performance over a large range of filling weights [1]. The combined use of the CFD and Particle Tracing modules was key in rationalising results and supporting the development of the deagglomeration engine.