Workshop

We have performed Computational Fluid Dynamics−Discrete Element Method (CFD−DEM) simulations of air and particles in a commercial ELLIPTA^® inhaler [1]. We simulated the fluidization, deagglomeration, and transport of carrier and API particles, with inhalation profiles representative of moderate asthma and very severe COPD patients and different mouthpiece geometries and powder doses. In each simulation, we determined the fine particle fraction (FPF) in the stream leaving the mouthpiece, the temporal evolution of the spatial distribution of the particles, the mean air (slip) velocity seen by the carrier particles, and the average numbers and normal impact velocities of carrier-carrier and carrier-wall collisions inside the inhaler. In the cases examined, the air-carrier and carrier-carrier interactions affected the FPF, while the carrier-wall interactions were too infrequent to have a substantial effect. The simulations revealed the benefit of loading both blisters even when only a single medication is delivered.

We then performed integrated simulations considering both the inhaler and the Mouth-Throat (MT) region to probe the deagglomeration, transport, and deposition in the MT region [2].

The principal findings from these simulation studies will be summarized in this presentation.

References

[1] Mostafa Sulaiman, Xiaoyu Liu, and Sankaran Sundaresan, A CFD-DEM investigation of powder transport and aerosolization in ELLIPTA^® dry powder inhaler, submitted for publication, 2022.

[2] Mostafa Sulaiman, Xiaoyu Liu, and Sankaran Sundaresan, under preparation, 2022.