inhalation drug delivery Flashcards
what defines a large particle
20micrometers
why would large particles deposit in the UA
impact and deposit on walls
low flow of air means particles will deposit on wall due to gravitational sedimentation
particles escape deposition via the exhaled air
where are large particles likely to be absorbed
the GI tract
why are particles absorbed by the GI tract
particles deposited in the upper ciliated airways carried up the airways to the throat and swallowed
what size defines a small particle
around 6.2 micrometers
where is impaction likely to take place with small particles
highly branched lower airways
why is sedimentation for small particles less significant in the upper airways
less inertia
what size defines a sub micron sized particle
0.6 micrometers
via what mechanism will sub micron sized particles likely to deposit
brownian diffusion
what reason would sub micron particles not impact in upper or lower airways
low momentum and low mass
issues with dry particles
they don’t dissolve well
what shape is best for an inhaled particle and why
elongated to decrease aerodynamic diameter
