Intranasal drug delivery by spray and drops

Area of Science:

• Nuclear medicine
• Pharmacokinetics
• Drug delivery systems

Background:

• Intranasal drug administration offers a direct route to the brain and systemic circulation.
• Understanding drug deposition and clearance is crucial for optimizing intranasal therapy efficacy.
• Human serum albumin labeled with Technetium-99m (99mTc-HSA) is a suitable radiotracer for studying nasal transport.

Purpose of the Study:

• To compare the nasal deposition patterns and clearance rates of human serum albumin (HSA) administered via spray versus drops.
• To evaluate the influence of administration volume (one vs. three drops) on nasal distribution.
• To provide data for optimizing intranasal drug delivery strategies.

Main Methods:

• Radiolabeling of human serum albumin with Technetium-99m (99mTc-HSA).
• Administration of 99mTc-HSA as a nasal spray, single drop, or three drops in normal subjects.
• Monitoring of nasal deposition and clearance using gamma scintigraphy.

Main Results:

• Nasal spray primarily deposited in the atrium with slow clearance to the pharynx.
• A single drop spread more extensively than the spray.
• Three drops effectively covered most of the nasal cavity walls.
• Nasal drop administration resulted in faster clearance compared to the spray.

Conclusions:

• The method of intranasal administration (spray vs. drops) significantly affects drug deposition and clearance kinetics.
• Drop-based delivery may offer advantages for wider nasal coverage and potentially faster systemic absorption.
• These findings are critical for designing effective dosage regimens for intranasal medications.