A United Airway: Bronchiectasis Is Also Associated With Chronic Rhinosinusitis and Nasal Polyps

Drug delivery to paranasal sinuses using pulsating aerosols

Chronic rhinosinusitis (CRS) is the major disorder of the upper airways, affecting about 10-15% of the total population. Topical treatment regimens show only modest efficacy, because drug delivery to the posterior nose and paranasal sinuses is still a challenge. Therefore, there is a high rate of functional endoscopic sinus surgery in CRS patients. Most nasally administered aerosolized drugs, like nasal pump sprays, are efficiently filtered by the nasal valve and do not reach the posterior nasal cavity and the sinuses, which are poorly ventilated. However, as highlighted in this review, sinus ventilation and paranasal aerosol delivery can be achieved by using pulsating airflow, offering new topical treatment options for nasal disorders. Radioaerosol inhalation and imaging studies in nasal casts and in healthy volunteers have shown 4-6% of the nasally administered dose within the sinuses. In CRS patients, significant aerosol deposition in the sinus cavities was reported before sinus surgery. After surgery, deposition increased to the amount observed in healthy volunteers. In addition, compared with nasal pump sprays, retention kinetics of the radiolabel deposited in the nasal cavity was prolonged, both in healthy volunteers and in CRS patients. These efficiencies may be sufficient for topical aerosol therapies of sinus disorders and, due to the prolonged retention kinetics, may reduce application modes, but have to be proven in future clinical trials. Pulsating aerosols may offer additional new topical treatment options of nasal and sinus disorders before as well as after surgery.

Clinical potential of pulsating aerosol for sinus drug delivery

There is a high incidence of nasal disorders including chronic rhinosinusitis (CRS), affecting ∼ 14% of the total population. However, a topical treatment regimen shows only modest efficacy, and drug delivery to the posterior nose, osteomeatal area, and paranasal sinuses is still a challenge. Therefore, the primary treatment option of CRS is functional endonasal sinus surgery (FESS). Most nasally administered aerosolized drugs are efficiently filtered by the nasal valve and do not reach the sinuses, the site of chronic inflammation. Sinus ventilation, nasal and paranasal aerosol deposition can be achieved by using a pulsating airflow, offering new topical treatment options for nasal disorders. Inhalation studies in nasal casts and in healthy volunteers have shown up to 8% of the nasally deposited drug within the sinuses, which could not be achieved using nasal pump sprays. In addition, compared with nasal pump sprays, retention kinetics of the radiolabel deposit in the nose was prolonged by about a factor of five. With this efficiency, topical aerosol therapies of sinus disorders can be achieved and, owing to the prolonged retention, reduced application modes are possible. This offers new treatment options of sinus-nasal disorders in comparison with or after FESS.