Evaluation of Inhaler Drug Delivery Finds Room for Improvement

A computational evaluation of drug delivery devices, such as inhalers, has found several ways that they can be improved, according to research published in Physics of Fluids.

By damaging environmental conditions in highly populated areas around the world, increased air pollution has exacerbated health risks for patients with pulmonary diseases, such as asthma or chronic obstructive pulmonary disease (COPD), according to the study authors. Many of these patients rely on pressurized metered-dose inhalers or drug powder inhalers to receive their medications, although these devices do not always optimally deliver the treatments.

“[Inhalers’] efficacy remains a great concern as only one-third of the total drug reaches the affected regions of the lungs,” said study co-author Suvash C. Saha, PhD, from the University of Technology Sydney, in a press release. “As a result, the drug loss and cost of the treatment become higher.”

To understand the efficacy of these systems, the researchers said predicting aerosolized or powdered drug deposition in the lungs is essential. To investigate this, the research team created a computational model to evaluate where improvements can be made.

They presented the findings in a realistic human lung model, according to the press release. Using computational fluid dynamics, the study found that more drug particles are deposited in the right bronchi than in the left, which is curved because of its proximity to the heart. The findings suggest that the drugs should contain smaller-sized particles to enable their reach in the distal bronchi.

“At higher flow rates, inertial impaction is found to be responsible for deposition of drug particles in the upper portion of the airways but with lesser availability of drug particles in the distal region of the airways,” said co-author Akshoy Ranjan Paul, PhD, in the press release. “Additionally, at lower flow rates, there is not enough momentum to carry particles to the distal region. As a result, there should be an optimum flow rate [to achieve] maximum reach of drug particles in the distal region.”

REFERENCE

Computational Evaluation of Drug Delivery Reveals Room for Inhalers Improvement. News release. Physics of Fluids; August 10, 2021. Accessed August 25, 2021. https://publishing.aip.org/publications/latest-content/computational-evaluation-of-drug-delivery-reveals-room-for-inhalers-improvement/