3 research outputs found
Salbutamol transport and deposition in healthy cat airways under different breathing conditions and particle sizes
Salbutamol is a bronchodilatator commonly used for the treatment of feline
inflammatory lower airway disease, including asthma or acute bronchospasm. As
in humans, a pressurized metered dose inhaler (pMDI) is used in conjunction with
a spacer and a spherical mask to facilitate salbutamol administration. However,
efficacy of inhalation therapy is influenced by different factors including the noncooperative character of cats. In this study, the goal was to use computational
fluid dynamics (CFD) to analyze the impact of breathing patterns and salbutamol
particle size on overall drug transport and deposition using a specific spherical
mask and spacer designed for cats. A model incorporating three-dimensional cat
airway geometry, a commercially available spherical mask, and a 10  cm spacer,
was used for CFD analysis. Two peak inspiratory flows were tested: 30  mL/s and
126  mL/s. Simulations were performed with 30s breathing different inspiratory
and expiratory times, respiratory frequencies and peaks. Droplet spray transport
and deposition were simulated with different particle sizes typical of the drug
delivery therapies (1, 5, 10, and 15  μm). The percentage of particle deposition
into the device and upper airways decreased with increasing particle diameter
during both flows imposed in this cat model. During increased mean ventilatory
rate (MVR) conditions, most of the salbutamol was lost in the upper airways. And
during decreased MVR conditions, most of the particles remained in suspension
(still in hold-up) between the mask and the carina, indicating the need for more
than 30  s to be transported. In both flows the percentage of particles traveling
to the lung was low at 1.5%–2.3%. In conclusion, in contrast to what has been
described in the human literature, the results from this feline model suggest
that the percentage of particles deposited on the upper airway decreases with
increasing particle diameter.This study is supported by grants PID2021-125731OB-C31 and PID2021-125731OB-C33 from the Spanish Ministry of Science and Innovation MCIN/AEI/10.13039/501100011033/ and FEDER (“A way to build Europe”)