pulmonary administration part 2 Flashcards
(44 cards)
for a drug to be delivered to respiratory tract, what must it be in the form of?
aerosol
what are the 4 factors that deposition is dependent on?
- patient factors
- formulation
- delivery device
- physiochemical characteristics of the drug
what is the most important physical property?
-aerodynamic diameter
what is the aerodynamic diameter dependent on (3 factors)
-size, shape and density of particle
in practice is it a polydisperse or monodisperse system
-polydisperse, but ideal to be mono disperse
what is the efficiency of the aerosol dependent on?
-deposition in respiratory tract
what is the site of deposition dependent on
-size of particle
under 10 particle size - where does it get deposited
-throat
5-10 particle size, deposition?
-upper airways
2-5 particle size, deposition?
-lower airways
0.5-2 particle size, deposition?
-alveolar region
under 0.5 size, deposition ?
-exhaled without deposition
under 0.1 size, deposition?
-alveolar region
where are the majority of B2 receptors located?
-pulmonary region
where are the majority of M3 receptors?
- tracheobronhcial region
- less in pulmonary region
where is salbutamol delivered to?
-pulmonary region
what are the three main mechanisms for particle deposition?
- inertial impaction
- brownian diffusion
- gravitational sedimentation
what are the two side mechanisms?
- electrostatic attraction
2. interception
does a particle have its own momentum when carried in aerosol stream?
-yes
what happens when aerosol stream meets bend or obstacle?
direction changes
what happens when the inertial force of particle interferes?
RESISTS change in direction
carries on original direction
where does this inertial impact happen?
- upper respiratory tract
- airflow is turbulent and air velocity is high
does this happen to larger particles?
-yes
what is gravitational sedimentation?
- sedimentation of particles
- due to action of gravitational forces
