Numerical simulation of in-vitro dispersion and deposition of nanoparticles in dry-powder-inhaler aerosols.
Aerosol dispersion and deposition inside an idealized mouth-throat has been numerically simulated using a stochastic Lagrangian model accounting for Brownian motion and particle-wall interaction. Delivery of nanoparticles to the lungs is extremely difficult, mainly due to their low inertia, and for this reason they are often loaded into larger carrier particles. Bearing in mind the potentialities of nanoparticles in advanced drug delivery, a set of monodisperse particles with diameters in the nanqsize range, as well as in the respirable and carrier ranges, were considered in the present simulations. Deposition patterns were obtained by tracking a total of 16,000 particles for each diameter. The results have shown that similar patterns were obtained in the mouth-throat for 400 nm particles and larger. A clear correspondence between secondary flow structures in the fluid and these deposition patterns was observed, demonstrating the role of the convective transport processes for this size range. In contrast, a much more uniform distribution of the particles adhering to the walls was noted for a size of 200 nm. It was also found that a very large amount of these particles (nearly 80%) is lost by deposition on the mouth-throat, thus recommending the use of larger carrier particles.
Mendes
P J
PJ
Dept. de Engenharia Mecânica, Instituto Superior Técnico, Universidade Thcnica de Lisboa, Av Rovisco Pais, 1049-001 Lisboa, Portugal.
Pinto
J F
JF
Sousa
J M M
JM
D000280:Administration, Inhalation; D000327:Adsorption; D000336:Aerosols / Q000737:chemistry*; D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D009055:Mouth / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D010614:Pharynx / Q000737:chemistry*; D011208:Powders; D015656:Respiratory Mechanics
D000336:Aerosols; D011208:Powders