Ultrasonic nebulization system for respiratory drug delivery

Area of Science:

• Pharmaceutical Sciences
• Biomedical Engineering
• Aerosol Science

Background:

• Respiratory drug delivery in animals requires precise aerosol generation.
• Existing methods may lack control over particle size and dosage.
• Ultrasonic spray technology offers potential for improved aerosol production.

Purpose of the Study:

• To evaluate an ultrasonic spray system for producing aerosols for animal respiratory drug delivery.
• To determine the effects of liquid flow rate and drug concentration on aerosol output and particle size.
• To assess the system's potential for controlled drug delivery in animal studies.

Main Methods:

• Utilized a Sono-Tek ultrasonic spray system with drying columns (charcoal/silica) for solvent removal.
• Tested drug solutions (sodium fluorescein, sodium cromolyn in water; budesonide, indomethacin in ethanol).
• Analyzed aerosol output via filter capture and particle size distribution using cascade impactors.

Main Results:

• Aerosol output increased proportionally with liquid flow rate and drug concentration.
• Mean particle size increased with solute concentration but was independent of liquid flow rate.
• Particle size distribution depended on solvent type, with good agreement between theoretical and observed sizes at high doses.

Conclusions:

• The ultrasonic spray system can generate aerosols with controlled particle size and a wide range of dose levels.
• The system shows promise for effective drug delivery testing in animals, including high-dose studies.
• Further optimization may be needed for precise particle size control at lower doses and with ethanol-soluble drugs.