Exhalation Delivery Systems (EDS) Greatly Increase Topical Delivery to Target Sites for Chronic Rhinosinusitis (CRS) Compared to Nasal Sprays or Pressurized MDIs (pMDI)
Monday, March 5, 2018
South Hall A2 (Convention Center)
Per G. Djupesland, MD, PhD, John C. Messina Jr., PharmD, Ramy A. Mahmoud, MD, MPH
RATIONALE: Labyrithine nasal passages, the narrow nasal valve and complex static and dynamic aerodynamics limit traditional intranasal steroids’ (INS) ability to effectively deliver medication to superior/posterior nasal regions. Exhalation delivery systems (EDS) exploit unique characteristics of nasal anatomy and aerodynamics to overcome these limitations and achieve superior/posterior drug delivery. We review published human in vivo gamma-scintigraphy deposition data for conventional INS (C-INS; e.g., Flonase/Nasonex), HFA-based pMDI’s (e.g., QNASL/Zetonna), and EDS systems for liquids and powders.

METHODS: Four recent gamma-deposition studies comparing different technologies for nasal delivery of topical steroids were included: (1) Conventional INS sprays (Flonase and Nasonex) versus pMDI (QNASL), (2) C-INS (Nasonex) versus pMDI (Zetonna), (3) C-INS versus EDS-liquid, (4) C-INS versus EDS-powder and EDS-liquid. Data on regional deposition and clearance was compared.

RESULTS: Qualitative deposition differences were large, though variability in segmentation methods prevents quantitative comparisons. In all studies, C-INS consistently deposit primarily anteriorly (in the valve region) with clearance along the nasal floor and little deposition in superior/posterior regions. Both pMDIs (QNASL/Zetonna) show a stationary “hotspot” in the non-ciliated vestibule, little delivery to superior/posterior regions, and minimal clearance. EDS (liquid or powder) produce less deposition in the valve area and broad deposition to superior/posterior segments with a different clearance pattern.

CONCLUSIONS: Human imaging data demonstrate poor drug deposition in superior/posterior sites with conventional nasal sprays, and greatly increased deposition throughout upper/posterior nasal passages with an EDS. In CRS, upper/posterior sites, including the middle and upper meatuses (ostiomeatal complex) where sinuses ventilate/drain and polyps originate, are the primary target for treatment.