Acoustic Aerosol Delivery: Assessing of Various Nasal Delivery Techniques and Medical Devices on Intrasinus Drug Deposition.

This study aims to evaluate the impact of the nasal delivery technique and nebulizing technologies (using different frequencies of oscillating airflow) for acoustic aerosol targeting of maxillary sinuses. Sodium fluoride (chemical used as a marker), tobramycin (drug used as a marker) and 99mTc-DTPA (radiolabel aerosol) were used to assess the intrasinus aerosol deposition on a nasal cast. Two commercial medical devices (PARI SINUS nebulizer and NL11SN ATOMISOR nebulizer) and various nasal delivery techniques (one or two nostrils connected to the aerosol inlet, the patient with the soft palate closed or open during the acoustic administration of the drug, the presence or not of flow resistance in the nostril opposite to the one allowing the aerosol to be administered) were evaluated. The closed soft palate condition showed a significant increase in drug deposition even though no significant difference in the rest of the nasal fossae was noticed. Our results clearly demonstrated a higher intrasinus aerosol deposition (by a factor 2-3; respectively 0.03 ± 0.007% vs. 0.003 ± 0.0002% in the right maxillary sinus and 0.027 ± 0.006% vs. 0.013 ± 0.004% in the left maxillary sinus) using the acoustic airflow generated by the PARI SINUS compared to the NL11SN ATOMISOR. The results clearly demonstrated that the optimal conditions for aerosol deposition in the maxillary sinuses were obtained with a closed soft palate. Thus, the choice of the nebulizing technology (and mainly the frequency of the pulsating aerosol generated) and also the recommendation of the best nasal delivery technique are key factors to improve intrasinus aerosol deposition.

Ventilation and aerosolized drug delivery to the paranasal sinuses using pulsating airflow - a preliminary study.

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.

Ventilation and drug delivery to the paranasal sinuses: studies in a nasal cast using pulsating airflow.

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 a nasal cast using dynamic 81mKr-gas imaging in combination with pulsating airflows. Furthermore, the efficiency of the deposition of radiolabelled aerosol was assessed. RESULTS: Pulsation increased ventilation efficiency of the sinuses more than fivefold and aerosol deposition efficiency more than twentyfold, compared to delivery without pulsation. Furthermore pulsation increased aerosol deposition in the nasal airways by a factor of three. Using pulsating airflow Kr-gas ventilation and aerosol deposition efficiencies increased with increasing sinus volume. Pulsating airflow resulted in a deposition of up to 8% of the nebulized drug within the sinuses compared to 0.2% without pulsation. 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.