Aerosols Flashcards
Basic principles of aerosols
pressurized dosage forms that emit fine dispersions of solid material and liquid droplets in a gaseous medium
Advantages of Pulmonary drug delivery
-smaller doses
-faster onset of action
- direct delivery
-can treat both pulmonary and systemic diseases
-lower side effect profile
disadvantages of pulmonary drug delivery
-only a small fraction dose is deposited in the lungs
-proper delivery depends on the techniques
-patient education required
-particle size control is required
what are the two zones of the lungs?
conducting:
respiratory:
how does particle size affect pulmonary drug delivery?
the size determines where it will “settle” and not be cleared by natural clearing methods so it can do what it’s supposed to do
-upper respiratory: 5-30 um
middle respiratory: 1-30um
lower respiratory: <1 um
what kind of particles must the aerosol “meds” be?
aerosol must be non-hygroscopic
hygroscopic particles draws in moisture. May become compacted and have bad flowability
what is inertion impaction?
the ability for the meds to be at the right speed and size to not get caught in the “nooks and crannies” or the lungs
what are aerosol systems?
two-phase
three-phase
foams
MDIs
Two-phase
Solution or suspension of active ingredient in a liquid propellant OR a mixture of liquid propellant and solvent. As the drug leaves the orifice, rapid expansion of propellant, and produces a fine spray. Simplest form
surface sprays, space sprays in addition to MDIs
What size particles are preferred when treating asthma?
Needs to be smaller particles in order to get to the Beta2 receptors which are more peripheral
How are aerosol systems “made”
pressure of aerosol is vital for its performance
blends of said propellant are used to achieve the desired vapor pressure
Propellant is important bc in addition to the particles, pt is also in having the propellant alongside with it so must not be irritating
What are three-phase systems generally used for?
water-based aerosols
Three-phase system
foam aerosol
not intended for oral use
compressed gas systems
environment friendly
mainstream application
propellant not as high
Requirements for Propellant
vapor pressure 15-10 psig at 70 degree F
low toxicity
chemically inert
nonflammable/nonexpensive
free from odor and color
good solvent powder
FINISH
Kinds of Propellants
fluorocarbons
hydrocarbons
compressed gases
Why are aerosol containers made out of aluminum rather then tin-plated steel or other metals?
if molded, will have sharp edges and will leak. aluminum, plain or coated is used bc it can be molded with smother “edges” to keep the med inside
Can stainless steel be used for aerosol container?
yes, but more expensive
Why is MDI more popular?
used longer
MDI?
metered-dose inhaler
MDI
-displays the number of doses left in the container as the patient uses it
-dual valve mechanism controls delivery
-expansion chamber helps with easier administration for patient (tighter seal-get more meds in) and slows down the particles
pt counseling
-hold upside down mdi–shake
dpi-horizontal -don’t shake
*proper holding technique
*shake or not device
*hold breath as long as possible then remove inhaler from mouth and exhale slowly
*recommend extension device if patient unable to use MDI
*instruct how to determine remaining doses
DPI?
dry powder inhaler
DPI
-needs to be shaken before each use to make sure each inhalation has uniformity
-more environmentally friendly
-twist, hear click, and inhale
-mixed with inner carrier molecules like lactose so will leave particle in mouth–recommended rinsing mouth after each use
why rinse mouth after using DPI?
steroids should not be left in the mouth–immunosuppressant
cold fill process
Cool down propellant to liquid form but can also bring in environmental water
Preferred aerosol packaging:
Pressure fill process
Why pressure fill process preferred
Prevents water contamination
Avoids propellant loss
Quality control tests of aerosols
-content
-flame extension test
-vapor pressure
-leak test
-spray pattern
Packaging, Labeling, and Storage
-package is part of the manufacturing process
-protective cap or cover to prevent accidental use
-storage in reasonable temperature
protect from excess heat and flame
dispose of preoperly
Kinds of topical aerosols
anti-infective agents
anti-inflammatory agents
anesthetic agents
