From the systemic drug delivery perspective, the lungs constitute the largest non-invasive route of delivery, estimated at over 100m 2 in an adult. It is the only available non-invasive route for many drugs that cannot be delivered through the digestive system due to degradation (e.g. proteins such as insulin). Increasing the bioavailability of inhaled therapeutics can decrease drug prices, and rendering this delivery route plausible for a higher variety of drugs, namely the ones currently delivered through injection. A few studies have experimentally proved the feasibility of using magnetic particles for increased drug deposition in the lungs. However, there is still a dearth of research available on the subject of delivery of magnetic particles to the deep regions of the lungs (acinar regions), and the dynamics and deposition in these regions are still poorly understood .To increase the deposition of the drug, magnetic particles may be influenced by an external magnetic field, whereby the magnetic force pulls on the magnetic particles, deflecting them from the flow streamlines and thus enhancing deposition. In the present talk we present simulations of magnetic particles dynamics in multi-generation (bifurcating) acinar geometries. CFD simulations were performed using Ansys Fluent to obtain the flow field in a moving/breathing geometry (dynamic mesh). To simulate particles` dynamics and deposition, an in-house Discrete Element Method (DEM) code was written. To further increase deposition rates, we suggest the use of a breath hold, allowing the magnetic field more time to act before exhalation. Results using this method will be compared to deposition under normal breathing patterns.
