Effect of Texture and Surface Chemistry on Deagglomeration and Powder Retention in Capsule-Based Dry Powder Inhaler

Area of Science:

• Pharmaceutical Technology
• Materials Science
• Biomedical Engineering

Background:

• Pulmonary delivery systems, particularly dry powder inhalers (DPIs), are crucial for administering therapeutic formulations to the lungs.
• Effective drug delivery relies on achieving high doses and optimal powder dispersion from the DPI.
• The impact of device surface properties on powder retention and deagglomeration remains understudied, potentially affecting the delivered dose.

Purpose of the Study:

• To investigate the influence of DPI surface modifications on powder deposition and deagglomeration.
• To explore how altering surface properties (hydrophilic-hydrophobic balance and topography) affects powder behavior within a model DPI.
• To identify surface characteristics that can optimize DPI performance for enhanced inhalation therapy.

Main Methods:

• Inner components of a model DPI were modified using plasma treatment to alter surface properties.
• Various plasma processes were employed to change both hydrophilic-hydrophobic characteristics and surface structure.
• Powder deposition and deagglomeration were quantified for untreated and modified DPI components.

Main Results:

• Surface topography modifications had a more significant impact on powder deposition and deagglomeration than hydrophilic or hydrophobic alterations.
• Increasing surface roughness in the mouthpiece region led to a substantial decrease in powder deposition (from 5% to 1%).
• No significant changes in powder deagglomeration were observed between untreated and modified devices.

Conclusions:

• Surface roughness, particularly at the nanoscale, is a critical factor in optimizing DPI performance.
• Increasing the surface roughness of DPI components, especially in the mouthpiece, can reduce powder loss and increase the delivered dose.
• Nanoscale surface engineering offers a promising strategy for the future optimization of dry powder inhalers to improve pulmonary drug delivery efficacy.