AERSOLS Flashcards
AEROSOL DOSAGE FORMS
Pressurized dosage forms that, upon actuation, emit a fine dispersion of liquid or solid materials containing one or more active ingredients in a gaseous medium
Inhalants
vicks / ammonia
amyl nitrate
Drug has a
- *HIGH VAPORPRESSURE**
- do not need propellant*
does not need anything for the
drug to be aerosoled
What Dosage Form?
Pressurized container
Solutions + Suspensions
CONTAINS PROPELLANT
admin by actuation
ex. Asthma drugs
AERSOL DOSAGE FORMS
includes
MDI’s
What Dosage Form?
Solid formulation in capsule / cartridge
not pressurized / no propellant
adminstered by ACTUATION
asthma drugs
DRY POWDER INHALER
DPI
What Dosage Form?
Drug solution administede with NEBULIZER
VENTURI Principle
Air pressure & droplet size important
INHALATION SOLUTION
Ideal respiratory delivery system
MDI & DPI
Formulation
stable formultion + package meeting design requirements
- *Bioavailability**
- *~1 micron partical size**
Compliance
ease of use & clinical advantages
counters / memory
- *Aerosol**
- *Properties**
- *Particle Size**
- *micronization –> ~1 micron size**
Physical Properties
density / spgr
- *Vapor Pressure**
- *escaping tendency // volatile CCl3F**
Chemical + Physical Stability
chemical reactivity / no rxn with package
Sealed canister containing formulation and propellant. Used in conjunction with an actuation device.
AEROSOLS
MDI / pMDI
could be continious or MDI
RAPID onset of action / EXACT dose
convenient / lower dose
Aerosol
Packaging / Components
RX products approved by FDA
CONTAINER
glass / pvc coated glass / metal / resin
VALVE Assembly
meter chamber for MDI
dip tube = al / resin / nlon
MDI Mouthpiece –> Actuator
MDI Spacer
Two-Phase System
Liquid propellant and vapor propellant
HIGH PROPELLANT CONTENT
Appropriate propellant combination
Three Phase System
WITH BALOON == WITH DRUG IN IT
drug that is SOLUBLE IN WATER
Aqueous, liquid propellant, and vapor propellant
Variable drug and propellant content
Appropriate propellant combination
Compressed Gas System
GAS PROPELLANT
N2 / CO2 / NO
no liquid component
HIGH DRUG Cntent
Propellants
Non-polar Liquid or Gas
CFC =
no longer used = deplete ozone
Non-CFC
CCl3F Trichlorofluoromethane (P-11) = propellant
CCl2F2 Dichlorodifluoromethane (P-12)
C2Cl2F4 Dichlorotetrafluoroethane (P-114)
Non-CFC Propellant
NAMING
CCl2F2
CCl2F2 = P-12
C = 1 - 1 // H = 0 +1 // F = 2
0 // 1 // 2
1st digit on right is number of F
2nd digit is 1 plus number of H
3rd digit is 1 minus number of C
Aerosol Formulation
when to use
SOLUTION or SUSPENSION
If the API is SOLUBLE in the PROPELLANT
V
USE SOLUTION
may add co-solvent –> aid solubility
alcohol /glycerol / propylene glycol
Specifications of Aerosols
PRODUCT REQUIREMENTS
Drug Content Assay
Dose UNIFORMITY // Particle size DISTRIUTION
Effect of STORAGE –> particle size
Plume Geometry
Profiling of actuations near canister exhaustion
Precautions of Active Ingredients
Nitroglycerin
Nitroglycerin is NOT FOR PULMONARY DELIVERY
Precautions of Active Ingredients
Anesthetics
ANESTHETICS ON BROKEN SKIN
Respiratory Drug Administration
SYNCHRONIZED
INSIPRATION + ACTUATION
Long -deep breath –> HOLD –> EXHALE
Non-pressurized device that, upon activation, delivers a fine particle size material transported by patient inhalation.
DRY POWDERED INHALER
Flovent (fluticasone) Diskus
Serevent (salmeterol) Diskus
Pulmicort (budesonide) Turbuhaler
Advantages of DPI
Rapid Onset
AVOID injection / First pass metaolism
PROTEIN absorption
DPI Formulation
Micron-Sized Drug in variety of delivery forms:
Crystal Form
Excipient binding / blending
Surfase passivation
Drug-excipient complexes
DPI Administration
- More than 25% of patients have difficulty with unit preparation
- More than 75% of patients have trouble with inhale, hold breath, exhale through mouth, etc. procedure.
VERY DIFFICULT FOR PATIENTS TO ADMIN
Initiate Dose / Activate Particles
SYNCHRONIZED INHALATION
Dose is Counted
rinse mouth
Inhalation Solutions
Commercial products are sterile solutions in glass vials or plastic blow-fill-seal containers.
Products added to nebulizer apparatus.
Nebulizer enables administration of appropriate size droplets by means of the Bernoulli principle and venturi effect.
Advantages of Aerosol Products
MDI / pMDI
Rapid Onset
EXACT DOSE
Convenience
What dosage form uses a
METERING CHAMBER?
MDI ONLY
also needs a mouthpiece –> actuatior
SPACER
Two Basic Propellant Systems
- *LIQUEFIED GAS**
- *in EQ w/ vapor pressure**
- *propellant vapor pressure** basis for aerosol use
- *COMPRESSED GAS**
- DECLINES WITH PRESSURE USE*
Valves
Continuous Vs Metered Dose
MDI = EXACT & REPEATABLE DOSE
Dip Tube structure –> product method of use
Pressurized Ideal respiratory delivery system
(MDI, DPI, and inhalation solutions/devices)
- *Formulation:**
- *Stable formulation**
- *including package** meeting design requirements
- *Bioavailability:**
- *Respirable particle delivery (1 micron particle size)**
- *Compliance:**
- *Ease of use and clinical advantages**
Metered dose inhaler (MDI)
Actuator, mouthpiece, metering chamber, and dip tube, and mouthiece
Two-phase system:
Liquid propellant and vapor propellant. High propellant content
- *Three-phase system:**
- *Aqueous**, liquid propellant, and vapor propellant. Barrier (Bag-in-can, can-in-can)
Appropriate propellant combination
- *Dry powder Inhalers (DPI) –**
- Non-pressurized device* that, upon activation,
delivers a fine particle size material transported by patient inhalation.
Solids formulation in capsule or cartridge
1 micron particle size with carrier system
Not pressurized – no propellant
Administered by actuation
AEROSOL PHARMACIST COUNSELING
MDI and DPI relatively difficult for patient use. -
- *anesthetics on broken skin,
- Nitroglycerin not for pulmonary delivery***
Respiratory drugs – Synchronize inspiration with actuation
Long deep breath – hold – exhale. Repeat after a few seconds
Hold container in correct position – Upright or inverted
Shake container to mobilize particles
Firm pressure on actuator
Prime delivery device –first use (or after storage)
Ostwald Ripening
Particle Size INCREASE
particles crystallize or deposit into larger sizes
ISSUE WITH TEMPERATURE for AEROSOLS
STORAGE
Describe the propellant system that would be used for a MDI. Explain in one sentence why is this an appropriate system
Liquified gas.
Vapor pressure remains constant throughout product use.
Key point is constant vapor pressure or provides uniform dose throughout entire container.
Describe two different applications of vapor pressure in inhalation dosage forms
MDI =
Vapor pressure is the propellant
Inhalants
DRUG ITESELF has vapor pressure
VICKS, you can just inhale it
- Three reasons why patents must store aerosol dosage forms at the specific storage temperature
Too cold could affect vapor pressure propellant
Too hot
could cause explosion – too much pressure
Drug stability –
too hot could accelerate drug degradation reactions
Particle size increase
due to temperature cycling or Ostwald ripening.
- Why use a cosolvent in an MDI formulation? Provide an example cosolvent molecule
A cosolvent enables an insoluble API to dissolve thereby providing a solution dosage form instead of a suspension dosage form.
Example cosolvents are
ethanol, propylene glycol, or other glycol
(accept other semi-polar solvents).
Why calculate the vapor pressure of the propellant mixture in an aerosol dosage form?
The vapor pressure must be appropriate for the intended use.
Surface sprays, room sprays, sprays used for long distance spraying, foams, MDI, etc.
all have different vapor pressure requirements.
Also accept that the vapor pressure must not be too strong or powerful for human administration to the throat and lungs.
What is the effect of the dissolved formulation ingredients
on the vapor pressure of a pharmaceutical aerosol product? Why?
Vapor pressure lowering.
Vapor pressure is a colligative property which is affected by molecules in solution.
The propellant mechanism in a compressed gas aerosol and in an MDI aerosol are identical.
False.
The MDI uses an equilibrium between liquid and vapor propellant.
The compressed gas uses only gas under pressure
Using micronized drug in a nasal spray formulation will enable the API to reach the alveoli in the lung.
False.
The micronized drug gets to the lung in an MDI, but not in a nasal spray.