Dry Powder and Budesonide Inhalation Suspension Deposition Rates in Asthmatic Airway-Obstruction Regions

Area of Science:

• Respiratory Medicine
• Pharmacology
• Biomedical Engineering

Background:

• Inhaled corticosteroids are standard therapy for bronchial asthma.
• Current inhalation devices produce a wide range of particle sizes.
• Effective drug delivery to the airway obstruction region is crucial for asthma management.

Purpose of the Study:

• To compare the deposition rates of different budesonide formulations and devices in the airway obstruction region.
• To identify inhalation therapies that maximize drug delivery to the tracheobronchial area.
• To determine the optimal particle size for budesonide deposition in asthma.

Main Methods:

• Utilized Weibel's anatomical data to define the airway obstruction region (1st-4th bronchial generations).
• Analyzed budesonide particle size distribution and average diameter for various delivery systems.
• Measured drug deposition using High-Performance Liquid Chromatography (HPLC) with a Cascade Impactor.

Main Results:

• Particles sized 2-6 µm are optimally deposited in the identified airway obstruction region.
• Jet-type NE-C28 suspension (78.0%) and mesh-type NE-U22 suspension (59.0%) showed higher proportions of optimal particle sizes compared to dry powder inhalers (Turbuhaler 33.0%, Symbicort 32.0%).
• The NE-C28 nebulizer delivered 2.36 times more budesonide to the target region than dry powder systems.

Conclusions:

• Electric nebulizers are more effective than dry powder inhalers for budesonide delivery in asthma.
• The jet-type NE-C28 suspension demonstrates superior efficacy in delivering budesonide to the airway obstruction region.
• Optimizing particle size is key to enhancing inhaled corticosteroid therapy for bronchial asthma.