Investigating deposition efficiency ratio of intranasal spray device within human respiratory models: Fusing experiments and simulations

Intra-nasal sprays for drug delivery are becoming more favored due to their ease of production and non-invasiveness. This variation of delivery targets areas of high permeability within the respiratory tract, such as the nasopharynx, allowing rapid diffusion across the membrane to treat respiratory infections, making it advantageous for pharmaceutical applications. For performance enhancement of intra-nasal sprays, specific particle sizes, density, and plume angle optimization were investigated by computational simulations on three-dimensional anatomical upper airway geometries reconstructed from high-resolution computed tomography scans. To validate in silico, colored dye in pharmaceutical-grade nasal sprays was administered into a resin 3D print of anatomical geometry maintaining a normal breathing rate of 15 LPM, using a vacuum pump and through image processing, we have quantified the deposition efficiency ratio of both nostrils. The experimental results align with simulation data that the particle size over 25 microns achieve the highest nasopharyngeal deposition. Fusing our experimental and simulation data suggests that the rational optimization of the intranasal spray design is attainable, with substantial enhancement of targeted drug delivery to the nasopharynx.