Abstract:
The pulmonary route is the pathway to transport aerosolised drug particles into the
tracheobronchial airways to treat and prevent respiratory diseases. Lung cancer is a frequently
diagnosed respiratory disease caused by particulate matter in the environment, especially among
older individuals. It is evident that as age increases, the lung airway diameters reduce, and this
geometric alteration due to aging affects the breathing capacity, transportation, and deposition
(TD) of inhaled drugs. A precise understanding of the inhaled particles TD through age-specific
unhealthy respiratory tracts containing a tumor can potentially optimise lung cancer treatment,
especially among aged individuals, which has not been investigated in the existing literature.
This study investigates the aging effect on the deposition of inhaled drug particles on the glomus
tumor present in the upper airways of the human respiratory tract. The CFD model predicts that
particle deposition on the tumor wall is higher in the 70-year-old lung for the particle sizes
ranging from 5-10 μm, while the maximum deposition efficiency of 10-20 μm particles is found
in the lung of a 50-year-old individual. The results of the numerical study show that particle sizes
ranging from 10-14 μm are deposited with higher efficiency on the tumor wall as compared to
the smaller size particles (5-9 μm) for 50, 60 and, 70 age. The flow disturbances are found
maximum in the airway downstream of the tumor. Furthermore, the effect of different inhalation
flow rates on particles (TD) is also investigated. The obtained patterns of airflow distribution and
deposition efficiency on the tumor wall and in the upper tracheobronchial airways would be
beneficial for developing an efficient and targeted drug delivery system.
