The document discusses quality control and evaluation tests for pharmaceutical aerosols. It defines aerosols as pressurized dosage forms that emit fine dispersions of materials upon actuation. Quality control tests evaluate properties of propellants, containers, valves, and product concentrates. Tests include vapor pressure determination, leak testing, and spray pattern analysis. Evaluation tests assess physicochemical characteristics, performance, and biological activity to ensure safety, efficacy, and consistency of pharmaceutical aerosols.

2. Quality control tests and Evaluation
tests of Pharmaceutical Aerosol
~ Prepared by
Pritom Sinha
ID – 17100086 (9th Batch)
Department of Pharmacy
Ranada Prasad Shaha University

3. Aerosol
“Aerosol is a pressurized dosage forms containing one or more therapeutic active
ingredients which upon actuation emit a fine dispersion of liquid and/or solid materials
in a gaseous medium”.
 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).

4. Aerosol Components
 Propellant
 Container
 Valve and actuator
 Product concentrate

5. Advantages
 Easily withdrawn of drug.
 Easy and convenient to apply.
 Faster Onset of action.
 No manual/ direct contact with the medicament.
 Avoid the first pass metabolism.
 A specific amount of dose or drug can be removed.
 No microorganism can enter.
 Release the contents in Controlled and Uniformly.
 Protect the photosensitive medicaments and oxygen sensitive material.
 Provides efficacy of a drug.
 Irritation can be reduced.

6. Disadvantage
 Expensive.
 Chlorofluorocarbon propellants cause Ozonelayer depletion.
 Inflammability.
 Toxicity.
 Explosivity.

7. Quality control tests
• It include tests of :
 Propellants
 Valves, Actuators, Dip tubes
 Containers
 Weight Checking
 Leak testing
 Spray testing

8. Quality control tests
Propellants
 A sample is taken out & vapor pressure is determined which is then compared to
specifications.
 Gas chromatography is used to determined the identity of the propellant.
 Purity of the propellant is checked by moisture, halogen & non volatile residual
determinations.

9. Quality control tests
Valves, Actuator & Dip Tube (Testing Procedure)
 Take 25 valves and placed on containers filled with specific test solution.
 Actuator with 0.020 inch orifice is attached.
 Temperature 25±1°C.
 Valve is actuated to fullest extent for 2 sec and weighed.
 Again the valve is actuated for 2 sec and weighed.
 Difference between them represents delivery in mg.
 Repeat this for a total of 2 individual deliveries from each of 25 test units.
 Valve Delivery per actuation in µL = Individual delivery weight in mg / Specific gravity of
test solution
Valve Acceptance : Deliveries Limit’s
54µL or less ± 15%
55 to 200 µL ± 10%

10. Quality control tests
Valves, Actuator & Dip Tube (Testing Procedure)
Out of 50 deliveries:
 If 4 or more deliveries are outside limits, then valves are rejected.
 If 3 or more deliveries are outside limits, another 25 valves are tested.
 Lot is rejected if more than 1 delivery is outside specification.
 If 2 deliveries from 1 valve are beyond limits: another 25 valves are tested.
Containers
 Containers are examined for defects in linings. Quality control aspects include
degree of conductivity of electric current as measure of exposed metals. Glass
containers examined for flaws. The dimension of neck and other must be checked &
weight should be determined.

11. Quality control tests
Weight checking
 It is done by periodically adding empty tared containers to filling lines which after
filling with product concentrate are removed and reweighed. Same procedure is
used for checking weight of the propellant.
Leak Test
 It is done by measuring the crimp’s valve dimension and comparing. Final testing of
valve enclosure is done by passing filled containers through the water bath.
Spray Testing
 It is done to clear up dip tube of pure propellant and concentrate and to check any
defects in the valve and the spray pattern.

12. Evaluation Test For Pharmaceutical Aerosol
(Flammability and combustibility)
Flame Projection
 The aerosol product is sprayed to an open
flame for about 4 second and the extension
of the flame is measured with the help of a ruler.
Flash Point
 The aerosol product is chilled to a temperature of
about -250F and transferred to the test apparatus.
The temperature of the test liquid is increased
slowly and the temperature at which the vapors
ignite is taken as the flash point.
Fig: Tag open cup apparatus

13. Evaluation Test For Pharmaceutical Aerosol
(Physicochemical characteristics)
1. Vapor Pressure » Pressure gauge,
» Can Puncturing Device.
2. Density » Hydrometer,
» Pycnometer.
3. Moisture » Karl Fisher Method,
» Gas Chromatography.
4. Identification of
propellants
» Gas Chromatography,
» IR Spectroscopy.
Property Method

14. Evaluation Test For Pharmaceutical Aerosol
(Performance Tests)
Spray Patterns
 The method involves the impingement of sprays on a piece of paper that has been
treated with dye-talc mixture. It gives a record of the spray pattern.
Aerosol Valve Discharge Rate
 An aerosol product of known weight is taken and its contents are discharged using
standard apparatus for a given period of time. The container is reweighed. Then the
change in weight per time dispensed is the discharge rate. The discharge rate can also
be expressed as grams per second.
Dosage with metered valves
 The doses are dispensed into the solvents or onto a material that absorbs the active
ingredients. The assay of the solution gives the amount of active ingredients present.

15. CONTD…
Net contents
 The tared cans are placed onto the filling line are weighed, the difference in weight is equal
to the net contents. The other method is a Destructive method and consists of weighing a
full container and then dispensing the contents. The contents are then weighed. The
difference in weight gives the amount of contents present in the container.
Foam stability
 The life of a foam ranges from a few seconds (for quick breaking foam) to one hour or
more depending on the formulation. The methods which are used to determine the foam
stability includes visual evaluation, time for a given mass to penetrate the foam, time for a
given rod that is inserted into the foam to fall and rotational viscometer.
Particle size determination
 Cascade impactor and light scattering decay methods are used for particle size
determination.

16. Evaluation Test For Pharmaceutical Aerosol
(Biological Testing)
Therapeutic Activity
 For Inhalation Aerosols - The determination of therapeutic activity is dependent on the
particle size.
 For Topical Aerosols - Therapeutic activity of aerosol products are determined by
applying the therapeutically active ingredients topically to the test areas and the
amount of therapeutically active substances absorbed is determined.
Toxicity study
 For Topical Aerosols - The topically administered aerosols are checked for chilling effect
or irritation in the skin.
 For Inhalation Aerosols: Inhalation toxicity study is done by exposing test animals to
vapors sprayed from the aerosol container.