Objectives: Topical delivery of drugs to the sinuses is challenging and requires also particular administration manoeuvres from the patient. This study was conducted to investigate 1) the delivery efficiency of a pulsating aerosol (Vibrent prototype device) to the sinuses and the nose, 2) the aerosol fraction that will deposit in the lungs and 3) potential differences regarding sinus and nasal deposition ratio when comparing aerosol administration during two different administration routes.
Methods: An open label deposition study in healthy volunteers was conducted using 99mTc-DTPA radiolabeled pulsating aerosols in comparison to nasal pump sprays. Deposition and retention of pulsating aerosols was assessed by gamma camera imaging during spontaneous nasal breathing and during closed soft palate administration.
Results: Aerosol administration during nasal breathing vs. application with closed soft plate results in significant lung, nasal and sinus deposition. No significant differences were observed for nasal clearance. In comparison, drug delivery using nasal pump sprays resulted in non-significant sinus, 100 % nasal and non-significant lung deposition. The clearance kinetics after nasal pump spray delivery was significantly accelerated.
Discussion: The standard application mode of pulsation aerosols with closed soft palate results in negligible lung deposition and therefore limits drug delivery to the nasal cavity only, minimizing unwanted side effects. Administration during spontaneous nasal breathing shows only 10% lung deposition, which is tolerable during drug administration. Relevant paranasal sinus deposition is noted during both application modes and clearance kinetics remains essentially unchanged. In contrast, nasal pump sprays do not show sinus drug delivery and nasal drug residence time is shortened.
Conclusion: Pulsating aerosols offer advantageous topical nasal and sinus drug delivery options.