Aerosol & Its Various Disscusion.

1. Aerosols- Containers and
Different Propellants Used
Prepared by:- Apurbaa Acharya
M. Pharm (Pharmaceutics), 1st year
Dr. B.C. Roy College of Pharmacy
and A.H.S
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2. CONTENTS
• Introduction.
• Advantages and disadvantages.
• Components of Aerosols.
• Propellants.
• Liquefied gas propellants.
• Compressed gas propellant.
• Nomenclature of propellants.
• Containers.
• Conclusion
• References
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3. Introduction
•Aerosol is defined as - A system that depends on the power of a
compressed gas or liquefied gas to expel the contents from the
container.
•Pharmaceutical Aerosol is defined as aerosol product containing
active ingredients dissolved, suspended or emulsified in a propellant
and intended for oral or topical administration or for administration
into the eye, nose ,ear, rectum and vagina.
•In 1942 - First aerosol was developed. (insecticide)
•In 1950 - Pharmaceutical aerosol for topical administration was
developed.
•In 1955 - Aerosol for the local activity in the respiratory tract was
developed (Epinephrine).
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4. Advantages & Disadvantages of Aerosols
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•A fixed dose can be administered
without contamination of materials.
•Stability is enhanced for those
substances which are adversely affected
by oxygen and/or moisture.
•Dose lowering and dose titration can
be achieved by metered dose system.
•The medication can be used for
localized action in a desired form.
•Irritation produced by the mechanical
application of topical medication is
reduced or eliminated.
•Ease and convenience of application.
• Rapid response to the medicament.
•Bypasses First pass effect.
•Expensive.
•Chlorofluorocarbon
propellants cause Ozone
layer depletion.
•Inflammability
•Toxicity

5. COMPONENTS OF AEROSOLS
• Propellant
• Container
• Valve and actuator
• Product concentrate
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https://image.slidesharecdn.com/aerosol-160620110446/95/aerosol-3-
638.jpg?cb=1467972135

6. PROPELLANTS
•Responsible for developing proper pressure within the
container.
•Provide driving force to expel the product from the
container.
TYPE OF PROPELLANTS
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(a)Liquefied gas Propellants
(b)Compressed gas Propellants

7. LIQUEFIED GAS PROPELLANTS
Some gases, especially hydrocarbons, tend to condense into
liquids at high pressure. When these gases are used they are
called liquefied gas propellants.
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CATEGORY CHEMICAL NAME/ EXAMPLE USES
Chloro Fluoro
Carbons
•Trichloromonofluoromethane-
Propellant 11
Used for oral or inhalation
purpose
Hydrocarbons •Propane- Propellant A-108
•Isobutane-Propellant a-31
Can be used for water based
aerosols and topical use
Hydro Chloro
Fluoro carbons/
Hydro Fluoro
Carbons
•Heptafluoro propane (HFA-227)
•Difluoroethane - Propellant 152a
Lower ozone destroying
effect.

8. COMPRESSED GAS PROPELLANT
Some gases can be compressed in a small volume and remain in
the gaseous form. When these are used to provide pressure to
remove a product from an aerosol can they are called compressed
gas propellants. Examples: Carbon dioxide, Nitrous oxide and
Nitrogen.
8http://resources.schoolscience.co.uk/BAMA/11-14/images/aerosol2a.jpg

9. NOMENCLATURE OF PROPELLANTS
• To refer easily to the Fluorinated hydrocarbons a relatively simple system of
nomenclature was developed by the “American Society of Refrigerating Engineers”
in 1957.
• According to this all propellants are designated by three digits(000).
• The first digit is one less than the number of carbon atoms in the compound (C-1).
• The second digit is one more than the number of hydrogen atoms in the
compound (H+1).
• The last digit represents the number of fluorine atoms (F).
• The number of chlorine atoms (for CFC’S) in the compound is found by subtracting
the sum of the fluorine and the hydrogen atoms from the total number of atoms
that can be added to saturate the carbon chain.
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10. CONTAINERS
• The containers must be able to withstand pressures as high as 140 to 180
psig (pounds per sq. inch gauge) at 130 ° F.
AEROSOL CONTAINERS
A . Metals
1.Tinplated steel
2. Aluminium
3. Stainless steel
B. Glass
1. Uncoated glass
2. Plastic coated glass
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http://www.wppg.com/media/6d4930f12a31ac62efa857ac0af4dd51.png

11. CONTAINERS (contd.)
• Tin plated steel containers consist of a sheet of steel plate, this sheet is coated with tin by
electrolytic process. When required it is coated with organic material usually oleoresin,
phenolic , vinyl or epoxy coating .
• Aluminium containers are manufactured by impact extrusion process. Resistance to
corrosion can be obtained by coating inside of the container with organic coating like
phenolic, vinyl or epoxy and polyamide resins.
• Stainless steel containers are generally used for inhalation aerosols. They are extremely
strong, non reactive or resistant to many materials and thus do not require internal coating.
They are comparatively costlier.
• Glass containers are preferred because of its Aesthetic value and absence of
incompatibilities. These containers are limited to the products having a lower pressure (33
psig) and lower percentage of the propellant. Used for topical and MDI aerosols.
Two types of glass aerosol containers are:
i) Uncoated glass container: Less cost and high clarity and contents can be viewed at all
times.
ii) Plastic coated glass containers: These are protected by plastic coating that prevents the
glass from shattering on breakage.
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12. CONCLUSION
• Aerosol is one of the best approach by which
we can ensure the optimum drug delivery to
system while avoiding the first pass
metabolism. It is also very patient convenient
and gives 50-70 % systemic availablity.
• At present there is much interest in
developing MDIs for diseases like asthma,
chronic bronchitis etc.
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13. REFERENCES
• https://t4.ftcdn.net/jpg/02/06/33/07/240_F_206330796_MGgjIinBcgkQyjQ
4MULxUyyWQ8VOv7s8.jpg (accessed on 3rd April 2019)
• http://www.wppg.com/media/6d4930f12a31ac62efa857ac0af4dd51.png
(accessed on 3rd April 2019)
• https://climate.nasa.gov/system/news_items/main_images/215_newsPage-
215.jpg (accessed on 3rd April 2019 )
• https://image.slidesharecdn.com/aerosol-160620110446/95/aerosol-3-
638.jpg?cb=1467972135 (accessed on 3rd April 2019 )
• http://resources.schoolscience.co.uk/BAMA/11-14/images/aerosol2a.jpg
(accessed on 3rd April 2019)
• http://www.wppg.com/media/6d4930f12a31ac62efa857ac0af4dd51.png
(accessed on 3rd April 2019 )
• Lachman/Lieberman's The Theory And Practice Of Industrial Pharmacy,
Fourth edition (Pb. 2015).
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