Impact of acoustic airflow nebulization on intrasinus drug deposition of a human plastinated nasal cast: new insights into the mechanisms involved.

PURPOSE The impact of 100 Hz (Hertz) acoustic frequency airflow on sinus drug deposition of aerosols was investigated using a human plastinated nasal cast. The influence of drug concentration and endonasal anatomical features on the sinus deposition enhanced by the 100 Hz acoustic airflow was also examined. METHODS Plastinated models were anatomically, geometrically and aerodynamically validated (endoscopy, CT scans, acoustic rhinometry and rhinomanometry). Using the gentamicin as a marker, 286 experiments of aerosol deposition were performed. Changes of airborne particles metrology produced under different nebulization conditions (100 Hz acoustic airflow and gentamicin concentration) were also examined. RESULTS Aerodynamic and geometric investigations highlighted a global behaviour of plastinated models in perfect accordance with a nasal decongested healthy subject. The results of intrasinus drug deposition clearly demonstrated that the aerosols can penetrate into the maxillary sinuses. The 100 Hz acoustic airflow led to increase the deposition of drug into the maxillary sinuses by a factor 2-3 depending on the nebulization conditions. A differential intrasinus deposition of active substance depending on maxillary ostium anatomical features and drug concentration was emphasized. CONCLUSION The existence of a specific transport mechanism of penetration of nebulized particles delivered with acoustic airflow was proposed.