we covered all the topics related to pharmaceutical aerosol in a clear and easily understandable manner with some of the pictorials attached to it. I think it will be sufficient for both your exams as well as for you seminar purpose even i also gave presentation on this. Hope this will be helpful for your reference purpose.

1. PHARMACEUTICAL AEROSOLS
BY
A.HIMA BINDU
16DU1R0001
B. PHARMACYSt. Ann’s college of pharmacy,
chirala.

2. CONTENTS
• INTRODUCTION
• HISTORY
• ADVANTAGES AND DISADVANTAGES
• COMPONENTS OF AEROSOL
• FORMULATION OF AEROSOLS
• TYPES OF AEROSOL SYSTEMS
• MANUFACTURING OF AEROSOLS
• PACKING, LABELLING AND STORAGE
• REFERENCES

3. INTRODUCTION
Pharmaceutical aerosols are defined as " Colloidal systems consisting of
very finely subdivided liquid or solid particles dispersed in and surrounded by gas ".
Pressurized packs.
Particle size : >50µm.
Aerosol products can be developed as
o NASAL INHALERS.
o DRY POWDER INHALER.
o NEBULIZER/ ATOMIZER.
o METERED DOSE AEROSOL INHALERS.

4. HISTORY
• In1941 - Americans Lyle Goodhue and William Sullivan, invented the modern
spray can.
• In 1942- First Aerosol was developed (Insecticide).
• In 1950- Pharmaceutical Aerosol for topical administration was developed.
• In 1955- Aerosols for the local activity in the respiratory tract was developed
(Epinephrine).

5. ADVANTAGES
Rapid onset of action.
Avoidance of manual contact with the medicament.
Immediate local application.
No contamination of the product.
DISADVANTAGES
High cost and expensive.
Highly flammable.
Toxic.
CFC can cause ozone layer depletion.

6. COMPONENTS OF AEROSOL
•PROPELLANTS.
•CONTAINERS.
•VALVE AND ACTUATOR.
•PRODUCT CONCENTRATE.

7. PROPELLANTS
• Generally propellant is regarded as the heart of the aerosol package.
• It provide driving force to expel the product from the container.
• TYPES OF PROPELLANTS
a) Liquefied gases propellants:
FLUORINATED HYDROCARBONS:
Eg. CFC, HCFC
HYDROCARBONS
b) Compressed gases propellants:
Eg. Ar, CO2.

8. LIQUEFIED GAS PROPELLANT
• Liquefied propellants are gases that exist as liquids under
pressure.
• Because the aerosol is under pressure propellant exists mainly as
a liquid, but it will also be in the head space as a gas.
• The product is used up as the valve is opened, some of the liquid
propellant turns to gas and keeps the head space full of gas.
• In this way the pressure in the can remains essentially constant
and the spray performance is maintained throughout the life of
the aerosol.

9. COMPRESSED GAS PROPELLANT
• It occupies the headspace above the liquid out of the
can.
• When the aerosol valve is opened the gas pushes the
liquid out of the can.
• The amount of gas in the head space remains the same
but it has more space, and as a result the pressure will
drop during the life of the can. Spray performance is
maintained however by careful choice of the aerosol
valve and the actuator.

10. CONTAINERS
• They must be able to withstand pressure as high as 140 to 180 psig at 130ºF.
METAL CONTAINER
TIN PLATE STEEL CONTAINER:
contains electroplated sheet.
ALUMINIUM CONTAINER:
great resistance against corrosion.
light weight.
STAINLESS STEEL CONTAINER:
Limited for smaller size.
Can withstand pressure.
Strong and resistant to moisture.

11. GLASS CONTAINER
• Preferred because of its aesthetic value and absence of incompatibilities.
• Limited to the products having low pressure and low % of propellant.
• Used for topical and MDI aerosol.
• Types:
i. Uncoated glass container
 less cost
 high clarity
ii. Plastic coated glass container
 prevents the glass from shattering during breakage.

12. VALVE:
• Capable of delivering the contents in the desired form such a spray, foam, solid
stream etc.
• TYPES OFVALVE
i. Continuous spray
ii. Metered valve
• VALVE ASSEMBLY

13. ACTUATORS
• These are specially designed buttons which helps in the delivering the drug in the
desired form i.e; wet stream, foam or solid stream.
• TYPES OF ACTUATORS:
i. Spray actuator
ii. Foam actuator
iii. Solid steam actuator
iv. Special actuator

14. FORMULATION OF AEROSOLS
• The formulation consists of 2 essential components:
i. PRODUCT CONCENTRATE
o It includes mixture of active ingredient and other necessary agents (solvents,
surfactants etc.).
ii. PROPELLANT
o Single or blend of propellants and solvents are used to achieve the desired
solubility.
o It should be selected to give the desired vapour pressure, solubility and particle
size.

15. TYPES OF AEROSOL SYSTEMS
1. SOLUTION SYSTEM/ TWO PHASE SYSTEM
• Simplest system.
• Contains liquid phase and solid phase.
• Creates homogenous system due to dissolved or dispersed propellants and
solvents.
• On activation of valve, pressure of vapour phase causes liquid phase to rise in dip
tube and expelled from the container.

16. 2.THREE PHASE SYSTEMS
a. A layer of water immiscible liquid propellant.
b. A layer of highly aqueous product concentrate.
c. A vapour phase.
• Mostly used when formulation requires the presence of a liquid phase that
is propellant immiscible.
• When aerosol valve is actuated , the pressure of the vapour phase causes
the liquid phase to rise in the dip tube and gets expelled.

17. MANUFACTURING OF AEROSOL

22. • Aerosols should be maintained with the protective caps in place to prevent
accidental activation of the valve assembly/ contamination by dust and other
foreign materials.
• Medicinal aerosol that are to be dispersed only upon prescription.
• An aerosol required to be labelled “flammable”.
• Exposed to temperature above 49ºc may burst an aerosol container.
• Generally recommended for storage between 15ºc and 30ºc.

23. REFERENCES
• “The Theory & Practice Of Industrial Pharmacy” by Leon Lachman,
H.A., LIEBERMAN.
• Sciarra, JJ., Stoller, L., 1998.The science and technology of aerosol
packaging. A Wiley-interscience publication, NewYork, 247-255.
• Remington’s “The Science & Practise of Pharmacy” 21st Edition,
Volume-1.