Background: Although there is a high incidence of nasal disorders including chronic sinusitis, there is limited success in the topical drug delivery to the nose and the paranasal sinuses. This is caused by the nose being an efficient filter for inhaled aerosol particles and the paranasal sinuses being virtually non-ventilated.
Method: The objective of this study was to visualize the efficiency of sinus ventilation in healthy volunteers using dynamic 81mKr-gas imaging in combination with pulsating airflows. Furthermore, the deposition and retention of 99mTc-DTPA aerosol particles was assessed.
Results: The ventilation of the maxillary and frontal sinuses could be visualized by gamma camera imaging during pulsating airflow. In addition, using pulsating airflow, between 3% and 5% of nasally deposited aerosols penetrated into the paranasal sinuses while during application without pulsation aerosol deposition was below 1%. Furthermore pulsation increased aerosol deposition in the nasal airways by a factor of three.
Conclusions: The study demonstrates the high efficiency of a pulsating airflow in paranasal sinus ventilation and aerosolized drug delivery. This proves that topical drug delivery to the paranasal sinuses in relevant quantities is possible and indicates further clinical studies are necessary.