A nebulizer system for highly reproducible aerosol delivery

Area of Science:

• Pharmaceutical Technology
• Respiratory Medicine
• Biomedical Engineering

Background:

• Nebulizer system performance is affected by inspiratory flow, ambient temperature, humidity, and solution surface tension.
• Variability in droplet characteristics leads to inconsistent delivery of aerosolized drugs.
• Potent drug delivery requires nebulizer systems with consistent aerosol output and a high respirable fraction.

Purpose of the Study:

• To evaluate the aerosol output characteristics of the PARI IS-2 nebulizer system.
• To assess the impact of varying inspiratory flow and ambient conditions on droplet size and output rates.
• To determine the dose delivery efficiency of the PARI IS-2 for potent aerosolized drugs.

Main Methods:

• Laboratory testing using a Malvern Particle Sizer to analyze droplet characteristics.
• Measurement of total and effective aerosol output rates.
• Simulation of different inspiratory flows (5-20 l/min) and ambient conditions (20-80% r.h.) using preconditioned air.

Main Results:

• Minimal effect on droplet sizes (MMD 3.0-3.6 microns) across tested inspiratory flows and ambient conditions.
• Total and effective output rates showed linear proportionality with inspiratory flow (5-20 l/min).
• Total output varied minimally (+/- 6%) with relative humidity changes (20-80% r.h.).
• Dose delivery ranged from 28% to 67% for initial fill volumes of 0.5 to 3 ml.

Conclusions:

• The PARI IS-2 nebulizer system provides highly consistent aerosol output and a significant respirable fraction.
• The system effectively compensates for inspiratory flow variations and maintains stable output under different humidity levels.
• Standardized breathing with the manual interrupter enables effective lung deposition of therapeutic aerosols.