Inhalable Nano-Dimpled Microspheres Containing Budesonide-PLGA for Improved Aerodynamic Performance

Area of Science:

• Pharmaceutical Sciences
• Biomedical Engineering
• Materials Science

Background:

• Dry powder inhalations (DPIs) offer environmental and stability advantages over other inhalation methods.
• Optimizing drug deposition in the deep lung is crucial for therapeutic efficacy in DPIs.
• Surface properties of microparticles can influence aerosolization and aerodynamic performance.

Purpose of the Study:

• To engineer microspheres with nanoscale dimples.
• To investigate the impact of surface roughness on inhalation efficiency.
• To evaluate the aerodynamic performance and lung deposition of dimpled microspheres.

Main Methods:

• Microspheres with dimpled surfaces were fabricated using oil-in-water emulsion-solvent evaporation.
• Physicochemical properties of the microspheres were characterized.
• In vitro aerodynamic performance was assessed using particle image velocimetry and computational fluid dynamics.

Main Results:

• Dimpled microspheres exhibited improved aerosolization characteristics, including reduced axial velocity.
• Computational fluid dynamics confirmed that dimpled surfaces promote deep lung transit.
• Andersen Cascade Impactor tests showed a higher fine particle fraction for dimpled microspheres.

Conclusions:

• Nanoscale surface roughness, specifically dimples, enhances the aerosolization and aerodynamic performance of microspheres.
• Dimpled microspheres demonstrate improved potential for deep lung deposition, increasing inhalation efficiency.
• Surface modification of microparticles is a viable strategy to optimize DPI formulations.