Nasal gel and olfactory cleft

Area of Science:

• Otorhinolaryngology
• Drug Delivery Systems
• Nasal Anatomy

Background:

• Intranasal drug delivery aims for targeted deposition, particularly in the olfactory cleft for systemic or central nervous system effects.
• The efficacy of intranasal gels depends on their distribution within the nasal cavity.
• Understanding deposition patterns is crucial for optimizing therapeutic outcomes.

Purpose of the Study:

• To determine if intranasal gel, administered via a radial-hole inhaler, reaches the olfactory cleft.
• To assess if different administration methods impact gel distribution within the nasal cavity.

Main Methods:

• Sixteen healthy volunteers received intranasal gel in each nostril using different administration methods.
• Nasal endoscopy was performed at 1 and 7 minutes post-administration to visualize gel deposition.
• Gel presence was recorded in specific nasal regions: olfactory cleft, middle turbinate, middle meatus, nasal vestibule, inferior turbinate, septum, and inferior meatus.

Main Results:

• No gel deposition was observed in the olfactory cleft, middle turbinate, or middle meatus.
• Gel consistently localized to the nasal vestibule.
• Significant differences in deposition rates were noted on the septum and inferior turbinate between the two administration methods.

Conclusions:

• Current intranasal gel administration methods, including the radial-hole inhaler, do not effectively deliver medication to the olfactory cleft.
• Gel distribution is primarily confined to the anterior and inferior nasal regions.
• Administration technique influences deposition patterns in specific nasal areas like the septum and inferior turbinate.