ppt on aerosol

1. Aerosol

2. Introduction
• It is a colloidal system of very finely
subdivided liquid or solid particles
dispersed in and surrounded by a
gas that depends on the power of a
compressed or liquified gas to expel
the contents from the container.
• Also called as pressurized packages,
or pressurized dosage forms.

3. Advantages
• Precise and consistent dosing, no guesswork.
• Direct delivery to the respiratory system, minimizing side effects and
maximizing effectiveness.
• Rapid drug absorption for quick relief, crucial for asthma attacks.
• Protects sensitive drugs from light, oxygen, or moisture, enhancing shelf life
and efficacy.
• Convenient and portable for easy self-administration.
• Inhalation bypasses liver’s first-pass metabolism for direct systemic
circulation.
• Tamper-proof, ensuring product integrity and safety.

5. Disadvantage
• Hard to evenly disperse insoluble drugs in propellant
• Expensive: Specialized equipment, testing needed.
• Containers may introduce trace metals, contaminating medication.
• Some propellants damage the ozone layer or release toxic VOCs.
• Certain propellants are flammable, posing safety risks

6. • Currently, pharmaceutical aerosols have moved away from chlorofluorocarbons
(CFCs) due to their harmful effects on the ozone layer.
• The most commonly used propellants now are:
• Hydrofluoroalkanes (HFAs):
• HFA-134a (1,1,1,2-tetrafluoroethane)
• HFA-227ea (heptafluoropropane)
These are considered environmentally friendly alternatives to CFCs because they:
Have zero ozone depletion potential
Have much lower global warming potential compared to CFCs
Are approved by regulatory agencies like the FDA and EPA
• HFAs have become the standard propellant in most modern pharmaceutical
aerosols, including metered-dose inhalers (MDIs) for respiratory medications. The
transition began in the 1990s following the Montreal Protocol, which aimed to phase
out ozone-depleting substances. Today, HFAs are the primary propellant choice due
to their environmental safety and compatibility with most pharmaceutical
formulations.

7. Containers
• Aerosol containers are made up of steel, aluminum, plastic or glass.
Tin plated steel which is light, relatively inexpensive is widely used.
• Aluminium containers are preferred to glass as they are lighter,
compact, non-fragile and light proof.
• Plastic has an advantage or safety and freedom from corrosion except
inter action of some perfumes with plasticizers.
• Glass containers for aerosol are uncoated or plastic coated glass.

8. Valves assembly
• Valve regulates flow of product from container
discharging product in definite spray such a spray
foam, cream or powder.
Selection of valve depend upon formulation and
application of product.
.

10. • Actuator: This is the part that you press to release the medication from the aerosol
canister. When pressed, it opens the valve to allow the medication to be dispersed.
• Stem: The stem is the part that connects the actuator to the valve mechanism
inside the canister. It transmits the force from the actuator to the valve.
• Stem Gasket: The stem gasket is a seal that helps prevent any leakage around the
stem, ensuring the medication is properly contained within the canister.
• Housing: The housing is the main body of the aerosol canister that holds all the
internal components, including the medication and propellant.
• Spring Mounting: The spring mounting is a component that helps secure the stem
and actuator in place, allowing for smooth, consistent actuation.
• Mounting Cup: The mounting cup is the base of the aerosol canister that helps
hold everything together and attaches to the canister.
• Dip Tube: The dip tube is a small tube that extends down into the liquid
medication inside the canister, allowing the propellant to draw up the medication
and deliver it through the actuator.

16. Propellant
• Propellants are gases having large expansion power that provides
necessary pressure within container.
• The propellants may be: liquified gas (e.g.: CFCs, hydrocarbon) or
compressed gas (e.g.: Nitrogen, Carbon dioxide, Nitrous oxide)
• CFCs were most widely used because gaseous at room temperature
and can also be easily liquified.
• Other: hydrocarbon propellants(propane, butane) though less
common in pharmaceutical aerosols due to flammability concerns

17. Principle of Aerosol
• When a propellant is sealed with drug ingredients in an aerosol container, an equilibrium is
quickly established between the liquefied and vaporized portions of the propellant.
• The vaporized portion exerts pressure inside the container, and this pressure forces the
liquid medication up the dip tube and out of the valve when the actuator is pressed.
• As the propellant mixes with air upon actuation, it expands and evaporates.
• The expanding and evaporating propellant carries the active drug ingredients along with it.
• If the active ingredients are soluble in the propellant, they will remain in the gaseous phase
• .However, if the active ingredients are less soluble, they may condense into tiny liquid
droplets as the propellant evaporates.
• These tiny liquid droplets form the aerosol spray that is dispensed when using an inhaler or
spray.
• The balance between gaseous and liquid drug particles depends on the solubility of the
active ingredients in the propellant formulation.

19. Manufacturing of aerosol
• Manufacturing of aerosols are carried out under low temperature and
high pressure (condition at which gas can be converted into liquid)
• So equipment capable of handling such conditions are required.
• Manufacturing is carried out in 2 stages:
Production of product concentrate
Addition of propellant to concentrate.

20. Addition of propellant to concentrate.
• Method 1: Pressure filling method
• This method involves filling the product
concentrate into the container at room
temperature.
• The valve is placed in the container and crimped.
• The propellant is added from a pressure burette
(capable of metering small volume of propellant)
under pressure into aerosol container through
valve stem.
• The desired amount of propellant is allowed to
enter the container under its own pressure until
the pressure between burette and container attains
equilibrium. (at this stage propellant stop flowing)

21. • Additional propellant can be added by increasing pressure in burette.
• For products getting affected by air, the air in the head space is
removed before adding propellant.

22. Method 2: Cold filling method
• propellant is chilled to -34.5o
C to -40o
C.
• The apparatus consists of insulated box
fitted with coiled copper tubings. Box is
fitted with a cooling system.
• Then propellant gas is passed through cool
coiled tube, propellant gets cooled and
liquified and filled in container.
• When desired propellant has been added
the valve assembly is inserted and crimped.
• The filled containers are then passed into a
heated water bath to test leakage and
container strength.
Propellant

23. QC of aerosol

24. QC for container parts
• Propellant: A sample is taken out and vapour pressure is determined.
All propellants are accompanied by specification sheet. Identification
of propellant can be conducted by gas chromatography. Purity of the
propellant can be measured by the presence of moisture, halogen and
nonvolatile residues.

25. Testing for valves

28. • Flame extension test: The product is sprayed for about 4 sec into a
flame. Depending on the nature of the formulation the flame extends.
The exact length is measured with the help of scale. A product is
considered flammable if a flame extends 18 inches (46 cm) or more, or
if the flame flashes back to the actuator, sometimes called “the
button.”
• Flash point: The aerosol product is chilled to -25o
F transferred to the
test apparatus. Temperature is increased slowly and the temperature
at which vapor ignites is taken as flash point. Test is carried out using
standard tag open cup apparatus.
• A higher flash point indicates a safer propellant. A liquid with a flash
point above 93°C (199.4°F) is not classified as flammable.
Flammability and combustibility test

29. standard tag open cup apparatus

30. Aerosol valve discharge rate
• This is determined by taking an aerosol product of known weight and
discharging the contents for a given time. After certain time, Aerosol
product is reweighed . And change in weight per time is its discharge
rate expressed in gm/second.
• Dosage with metered valves:
• Accurately weigh filled container and dispense several dosage. The
container is reweighed and difference in weight is divided by number
of dose dispensed.

31. • Net contents
• The uniformity in content of containers of a batch is determined by :
• First weigh the tared container. Then containers are filled and
reweighed.
• The difference in weight gives the net contents.

32. Stability testing
• Periodically, Sample containers are emptied for product concentrate and
propellant.
• Product concentrate are tested for changes in pH, density. Both product
concentrate and propellants are tested for identification using IR, gas
chromatography .
• Containers are also visually checked for possible corrosion (except glass
containers).
• Internal coating should be checked for softening, dissolving of polymer.
• Leaching tests need to be conducted for plastic containers.

33. Methods or steps of using MDI
• Hold the inhaler upright with thumb on base and index
finger on the top of canister and shake well.
• Remove the mouthpiece cover.
• Take deep breath in and then breathe out gently to empty
your lungs.
• Place the mouthpiece of the inhaler in mouth between
teeth and close the lips around it, do not bite.
• Start breathing in slowly and as the breathe is taken in the
canister is pressed down to release 1 dose.
• Continue to breathe in steadily and deeply. (3-5 seconds)
• Remove the inhaler from the mouth and hold the breath
for 30 sec, mouth being closed.
• Rinse your mouth out with water and spit it out.

35. Why rinse?
• Prevent Oral infection: Corticosteroids can increase your risk of
developing oral infection, a fungal infection in your mouth. Rinsing
your mouth with water helps to wash away any leftover medication
and reduce this risk.
• Corticosteroids can weaken your immune system and make you more
vulnerable to infection.

36. Assignment: Write method for rotahaler

37. Types of aerosol system
1. Solution system: System is also called 2 phase system consisting of
vapour and liquid phase. Usually, active ingredient is soluble in
propellant and no other additional solvent is required.
2. Water based system: In it, large amount of water is used to replace
all non-aqueous solvent. As propellants and water are not miscible. A
three phase aerosol forms (propellant, water and vapour phase).
Ethanol can be used as co-solvent to solubilize propellant in water and
also reduce surface tension to produce small droplets.

38. 3. Suspension system: It involves
dispersion of API in the propellant or
mixture of propellants. To decrease rate
of settling of dispersed particles,
suspending agents can be added. It is
primarily used for inhalation aerosols.
4. Foam system: Emulsion and foam
aerosols consist of active ingredients,
aqueous or non aqueous vehicles,
surfactant and propellant (hydrocarbon)
dispensed in the form of foam.
5. Intranasal system: They are aerosol
system intended for deposition of
medicament into nasal passages for local
or systemic effect.