Effect of post-administration head movements on nasal irrigation and mesh nebuliser mediated sinus drug delivery

Drug delivery to the sinonasal cavity is highly influenced by the head position and its movements, yet this influence remains insufficiently understood, limiting effective management of various nasal conditions including chronic rhinosinusitis (CRS). This study investigated the influence of post-administration head movement on nasal drug delivery efficiency using two drug delivery methods: nasal irrigation and mesh nebuliser systems. Drug delivery efficiency to each sinus and retained liquid mass in the nasal cavity were quantified using an ion tracing approach in realistic 3D-printed nasal replicas from non-CRS control and CRS patients post-endoscopic sinus surgery (ESS). The results indicated that ESS enhanced sinus delivery fraction (SDF) for both administration methods, with squeeze bottle SDF ranges across the maxillary sinuses of 0.92-2.11% in normal case versus 4.76-4.97%, in post-ESS case, and with 12 μm nebuliser SDF range of less than 0.05% in the normal model versus 2.87-3.60% in the post-ESS model. With nasal irrigation, in the post-ESS case, post-administration head movement significantly reduced SDF in the maxillary and sphenoid sinuses, while liquid mass retention decreased from 31.47 g to 9.52 g (approximately 70% reduction). Conversely, nebulisers showed lower sensitivity to head movement, with unaffected or even improved deposition in the frontal and maxillary sinuses in the post-surgery case. This study provides a comparative insight into the effects of post-administration conditions using current treatment approaches, highlighting the significant roles of nasal cavity geometry, delivery method, and head movement in developing effective sinus drug delivery strategies.