This document discusses aerosol packaging and summarizes the key components. It acknowledges those who provided guidance for the project. It then introduces aerosol sprays, noting they create a mist from a pressurized can. The document defines an aerosol and lists advantages such as targeted dosing and avoiding degradation. It also outlines disadvantages like cost and potential irritancy. The main components of an aerosol package are identified as the propellant, container, and valve/actuator. Different types of propellants are described including CFCs, HCFCs, HFCs, hydrocarbons, and compressed gases.

1. AEROSOL PACKAGING
Submitted by
ABINASH PATI
PG/K/16/02
Under the guidance of
Mr. N. NATRAJ

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ACKNOWLEDGEMENT
I acknowledge my sincere thanks to Mr. Natraj Nandamuru
(Class coordinator) for their advice and encouragement
extended to successfully complete this project.
I express my deep sense of gratitude towards my project guide
Mr. Shubhabrata Basu for their endless guidance and
technical support to help me in every step of my project.
I am very much thankful to the Deputy Director of IIP Kolkata
Mr. Bidhan Das for their constant support and guidance.

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INTRODUCTION
Aerosol spray is a type of dispensing system which creates
an aerosol mist of liquid particles. This is used with a can or bottle that
contains a payload and propellant under pressure. When the container's
valve is opened, the payload is forced out of a small hole and emerges as
an aerosol or mist. As propellant expands to drive out the payload, only
some propellant evaporates inside the can to maintain a constant
pressure. Outside the can, the droplets of propellant evaporate rapidly,
leaving the payload suspended as very fine particles or droplets. In 1939,
American Julian S. Kahn received a patent for a disposable spray
can, but the product remained largely undeveloped. Kahn's idea was to
mix cream and a propellant from two sources to make whipped cream at
home not a true aerosol in that sense. Moreover, in 1949, he disclaimed
his first four claims, which were the foundation of his following patent
claims. It was not until 1941 that the aerosol spray can was first put to
good use by Americans Lyle Goodhue and William Sullivan, who are
credited as the inventors of the modern spray can. Their design of a
refillable spray can dubbed the "bug bomb", is the ancestor of many
popular commercial spray products. Pressurized by liquefied gas, which
gave it propellant qualities, the small, portable can enabled soldiers to
defend malaria-carrying mosquitoes by spraying inside tents and
airplanes in the Pacific during World War II Goodhue and Sullivan
received the first Erik Rotheim Gold Medal from the Federation of
European Aerosol Associations on August 28, 1970, in Oslo, Norway in
recognition of their early patents and subsequent pioneering work with
aerosols. In 1948, three companies were granted licenses by the United
States government to manufacture aerosols. Two of the three companies,
Chase Products Company and Claire Manufacturing, still manufacture
aerosols to this day. The "crimp-on valve", used to control the spray in
low-pressure aerosols was developed in 1949 by Bronx machine shop
proprietor Robert H. Abplanalp.

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DEFINATION OF AEROSOL
An Aerosol is defined as "An aerosol is a disperse phase system, in which
very fine solid drug particles or liquid droplets get dispersed in the
propellants (gas), which acts as continuous phase".
ADVANTAGES OF AEROSOLS
 Required quantity of contents can be easily withdrawn from the
package without contamination or exposure of the remaining
material.
 Aerosols are easy and convenient to apply and can be administered
without the help of others.
 The onset of action is faster compared to other dosage forms because
the medicament is directly applied to the affected area /part.
 The dispersion of medicament is very good.
 Due to closed packing of aerosols, there is no manual/ direct contact
with the medicament.
 Aerosol form can avoid decomposition or inactivation of drug by the
pH or enzymatic action of the stomach or intestine and also can
avoid the first pass metabolism.
 A specific amount of dose or drug can be removed from the container
without contamination of remaining contents.
 Stability can be enhanced for those substances adversely affected
by atmospheric oxygen or moisture. (Hydrolysis of medicament can
be prevented since propellants do not contain any water. Oxidation
is prevented as no air is present in the container)
 Sterility can be for sterile product, because no microorganism can
enter even when the valve is opened.
 Metered valve can release the contents in Controlled and
Uniformly.
 The aerosol containers protect the photosensitive medicaments.
(Except clear glass containers)
 For Inhalation purpose a fine mist of the drug is produced.
 The rapid volatilization of the propellant provides a cooling,
refreshing effect.

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DISADVANTAGES OF AEROSOLS
 Aerosols are cost effective.
 Disposal of empty aerosol containers are difficult.
 Due to volatility of the propellant/s can irritate the injured skin.
 Some persons may be sensitive to the propellant/s and persons
who using an inhalation aerosol/s, the fluorinated hydrocarbons
may cause carcinotoxic effects on rapid and repeated use of the
aerosol product.
 Aerosol packs must away from temperature and fire, because it
may develop high pressure inside the container leads to explosion.
 If the drug is not soluble in the propellant, aerosol the formulation
is difficult.
 Sometimes propellants may cause toxic reactions, if therapy is
continued for a long period of time.
COMPONENTS OF AEROSOL IN PACKAGING
The following components / parts require for aerosol product:
1) Propellant
2) Container
3) Valve and Actuator

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1) Propellants:
Propellants are responsible for developing the pressure in the aerosol
container and also it expel the product from the container when the valve
is opened and helps in expels the product by atomization of contents or
foam production of the product.
When the propellant/s is a liquefied gas or a mixture of liquefied gases,
it frequently serves the propellant and solvent or vehicle for the product
concentrate.
Types of propellant
Depending on the route of administration and use, the propellant can be
classified as
I) Type-I Propellant Liquefied Gas
1) For oral and inhalation (Fluorinated hydrocarbons)
I) Tri-chloro-mono-flouro methane
II) Di-chloro di-fluro methane
III) Di-chloro tetra-fluro ethane
2) Topical Pharmaceutical aerosols (Hydrocarbons)
(1) Propane
(2)Butane
(3)Isobutene
II) Type-II Propellant Compressed Gas Propellants
3) Compound gases
Nitrogen
Carbon di-oxide
Nitrous oxide

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CHLOROFLUOROCARBON (CFC) PROPELLANTS
The basic characteristics of propellants are chemically inert, free from
toxicity, in flammability and explosiveness. Due to these characteristics,
the chlorofluorocarbon (CFC) propellants P-11, P-12 and P-114 etc., are
using in aerosol products from several years. Now-a-days their usage is
reduced, as they cause the depletion of ozone layer. The CFCs are using
in some aerosol products, due to their low toxicity and in flammability.
They are still use in small quantities in the treatment of asthma and
chronic obstructive pulmonary disease (COPD). P-134a and P-227 are
now been developed and are being incorporated in aerosol formulations
in place of P-12.
The CFCs are gases at room temperature that can be liquefied by cooling
them below their boiling point or by compressing them at room
temperature. For example, dichlorodifluoromethane (P-12) will form a
liquid (when cooled to - 21.6degF or compressed to 84.9 psia at 70degF)
(psia = pounds per square inch). Some liquefied gases also have a very
large expansion ratio compared to the compressed gases (e.g., nitrogen,
carbon dioxide). The usual expansion ratio for liquefied gases is about
240 which mean that 1 ml of liquefied gas will occupy a volume of
approximately 240 ml (it allowed to vaporize). Compressed gases
expansion ratio is about 3 - 10.
Hydro chlorofluorocarbons (HCFC) and Hydrofluorocarbons
(HFC)
The Hydro Chlorofluorocarbons (HCFC) and Hydrofluorocarbons (HFC)
differ from CFCs. These may not contain chlorine and contains one or
more hydrogens. These compounds break down in the atmosphere at a
faster rate than the CFCs resulting in a lower ozone depleting effect.
They are also slightly more flammable than the other propellants but this
is not perceived as a disadvantage.

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HYDROCARBONS PROPELLANTS
 The environmental acceptance, low toxicity and no reactivity are the
characteristics of hydrocarbons propellants allowing them to be used as the
propellant.
 Hydrocarbons are used in the preparation of water based aerosols as they are
stable to hydrolysis due to the absence of chlorine. Since they are immiscible with
water, they retain on the top of water.
 Hydrocarbons will develop good pressure to push the contents out of the
container.
 The disadvantage of Hydrocarbon propellants are flammability and explosive. So
the usage is reduced as propellant.
 Hydrocarbons do not contains halogens and therefore hydrolysis does not occur
making these good propellants for water based aerosols.
COMPRESSED GAS PROPELLANTS
The use of compressed gas like Nitrogen, Nitrogen dioxide and Carbon
dioxide as propellant/s, which emits contents in the form of fine mists,
foams, fine mists or semisolid. It produces fairly wet sprays and the
foams are not as stable as produced by the liquefied gas propellant.
Unlike the aerosol prepared with liquefied gas propellant, there is no
propellant reservoir. The compressed gas propellant is contained in the
headspace of the aerosol container which forces the product concentrate
to emit contents out of the container. For this higher gas pressure is
require in this aerosol. This aerosol finds its application to dispense food
products, dental creams, hair preparation and ointments.
Properties of Compressed Gases
Name Formula
V.P.
@70degF (psia)
B.P.
degF (1
ATM)
Gas Density
@70degF (g/ml)
Nitrogen N2
492 - 320 0.97
Nitrous Oxide N2O 735 - 127 1.53
Carbon Dioxide CO2
852 - 109 1.53

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Difference between Liquefied Propellant and Compressed Gas
Propellant

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Basic principle to release product concentrate from container
Liquefied propellant or propellant mixture exists in equilibrium with the
product concentrate in a sealed aerosol container. The liquefied
propellant vaporises and occupies the upper portion of the aerosol
container. As the liquefied propellant exists in equilibrium with the
propellant in the
Vapour phase in an aerosol container, so a constant pressure is
maintained within the aerosol container. Hence, it is called as "a
pressurised aerosol container".
The pressure exerted by the propellant is called as "vapour pressure",
measured in psig, is the characteristic of specific propellant. Upon the
actuation of the valve, the pressure exerted by the propellant is
distributed equally in all direction in the aerosol container, forcing the
product concentrate up the dip tube and out of the aerosol container. As
the vapour pressure of the propellant in air is lower than inside the
aerosol container, so the propellant evaporates on reaching the air and
product concentrates dries up as dry particles.
2) Aerosol Containers:
They must be stand at pressure as high as 140 to 180 psig (pounds per
sq. inch gauge) at 1300 F. The glass or metal containers are generally
used. Glass disadvantage is brittleness, so restricted usage of glass. If the

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pressure is less than 25 psig and propellant content is less than 15% then
glass can be used. It should be coated with plastic coating in two layers
if pressure is less than or equal to 33 psig. For linings Epoxy and vinyl
resins can be used. Vinyl resins can form strong lining but it will get
damaged by steam. But the epoxy resins can be used, as they are
resistant to steam. The products which have less pH, vinyl coating on the
epoxy coating is most suitable.
Choice of the material is depend on- Pressure of the system, whether
product is aqueous or not, pH of the product, physicochemical properties
of preparation.
Different types of materials for aerosol containers are:
(a) Metals
(b) Glass
(c) Plastics
(a) Metals:
1. Tinplated steel:
It is used for most aerosols as it is light inexpensive and durable.
It is steel that has been plated on both side with tin.
Tin plated steel containers are of two types-
(a) Two pieces container body, consisting of a drawn cylinder, the base
of the container, is held in place with double seam.
(b) The three piece container has aside seam the base being attached as
for two piece container, the top has a 1 inch opening and is joined to
body by double seaming to protect container from corrosion and also to
prevent the interaction between the tin and the formulation. Oleoresin,
phenolic, vinyl, or epoxy coatings are used as the coating materials. The
tin plated steel containers are used in topical aerosols.
Advantages:
 The aerosol cylinders are seamed and soldered to provide a sealed
unit.
 Special protective coatings are applied within the container to prevent
corrosion and interaction between the container and formulation if
necessary.

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Disadvantage:
 The main disadvantage of stainless steel containers is high cost.
 For small sized container only.
 Leak of container due to flaws in the seam or welding.
 Corrosion with some preparations.
2. Aluminum:
The aluminium containers are light weight and are less prone to
corrosion than other metals. Aluminium is used in most metered dose
inhalers (MDIs) and many topical aerosols. Epoxy, vinyl, or phenolic
resins coatings are done on aluminium containers to reduce the
interaction between the aluminium and the formulation. The seamless
aerosol containers manufactured by an impact extrusion process have
no leakage, incompatibility and corrosion.
The container themselves available in different sizes ranging from 10
ml to over 1,000 ml.
Advantages:
 These are manufactured by extrusion or by any other methods that
make them seamless.
 Against leakage the seam type of container is of greater safety.
 No incompatibility and corrosion.
Disadvantages:
 High cost.
3. Stainless steel:
Advantages:
 It is resistant to corrosion.
 No coating is required.
 It can withstand high pressure.
Disadvantages:
 Expensive.
 Which restricts its sizes to small sized containers.

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(b)Glass:
One of the materials is glass, limited usage because of its brittleness. So
glass containers are used in lower pressure and when low amount of
propellant are in use such as if the pressure is less than 25psig and
propellant content is less than 15%. In order to protect the glass
containers against breakage due to high pressure, it is to be coated with
plastic coating in two layers. Epoxy and vinyl resins can be used as
linings. Vinyl resins are not resistant to high temperature of the steam
about 200 0F. But epoxy resins are resistant to steam. These coatings are
suitable for low pH water based products. Used for some topical and MDI
aerosols.
Advantages:
 Glass has less chemical compatibility than metal containers.
 No corrosion.
 Glass can be moulded to different design.
 Glass containers preferred for aerosols.
Disadvantages:
 Glass containers must be precise to provide the maximum in pressure
safety and impact resistance.
 More chances for accidental breakage.
 Not suitable for photosensitive preparations.
(c)Plastic:
Plastics are more permeable to vapours and atmospheric air (like
oxygen), so it may interact with the formulation and also may lead to
oxidative degradation of the formulation. Polyethylene tetra phthalate
(PET) container as used for some non-pharmaceutical products.
Advantages:
 Cheap.
 Malleable and ductile.
 Easy to mould.
Disadvantages: Incompatibility between drug- plastic and may lose its
efficiency and potency.

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VALVE AND VALVE ASSEMBLY
Valves deliver the drug in desired form and regulate the flow of product
concentrate from the container. The valve should be able to withstand
the pressure encountered by product concentrate and the container,
should be corrosion resistant. They also provide proper amount of
medication. Dispersing of potent medication at proper dispersion/ spray
approximately 50 to 150 mg +-10 % of liquid materials at one time use
of same valve.
There are two types of valves are available,
a) Continuous spray valve.
b) Metering valve.
a) Continuous spray valves: To deliver the contents in spray or foam
or solid stream continuously with or without measuring and for
continuously. These types of valves are used for all types of
pharmaceutical aerosols.
b) Metering valves: For potent medication and exact amount of
medicament will be dispensed at one time application. Approximately
50 to 150 mg +- 10% at one time application.
Valve Assembly and its components:
Actuator
Valve stem
Gasket
Valve Spring
Ferrule/Mounting cup/Valve cup
Valve Body/ Housing
Dip tube

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Actuator:
It ensures that aerosol product is delivered in the proper and desired
form. It allows easy opening and closing the valve. The actuator or
adaptor which is fitted to the aerosol valve stem is a device which on
depression or any other required movement opens the valve and emits
the spray to the applied area. The design of the actuator which
incorporates an orifice of varying size and shape and expansion chamber
is very important which influences the physical characteristics of the
foam or spray, particularly in the case of inhalation aerosols, where the
active ingredient/s must emit in the proper particle size range. Some
proportion of the active ingredient/s is usually deposited on the inner
surface of the actuator, the amount available which released by actuation
of the valve.
Stem: The actuator is supported by the stem and the formulation is
delivered in the proper form to the chamber of the actuator by the stem.
It is made up of Nylon, Delrin, Brass and Stainless steel.
Gasket: The stem and valve are placed tightly in their place by the
gasket and the leakage of the formulation is prevented by gasket. It is
made up of Buna N and Neoprene rubber.
Spring: The gasket of aerosol container is held in its place by the spring
and also helps to keep the valve in closed position when the pressure is
released upon actuation of the formulation.

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Mounting Cup or Ferrule: The Mounting cup or Ferrule is generally
made up of aluminium which serves to place the valve in its position and
then attached to the aerosol container. So the underside of the mounting
cup/ Ferrule is exposed to the contents of the container. So it is to be
compatible with the contents to prevent interaction/s. It may be coated
with an inert material such as vinyl coating as it prevents any interaction
with the contents also corrosion of aluminium is prevented.
Housing or Valve body: The Housing or Valve body located directly
below the Mounting cup or Ferrule is made up of Nylon or Delrina work,
which uses to connect dip tube, stem and actuator of aerosol container.
The size of orifice will determine the rate of delivery of product and the
desired form in which the product is to be emitted. (Size is 0.013 to 0.080
inches)
Dip Tube: The dip tube is made up of polyethylene or polypropylene
extends from the housing body or valve body down into the product
concentrate works to bring the formulation from the container to the
valve. The inner diameter of the dip tube depends on the viscosity and
the desired rate of delivery of the product. The inner diameter of the dip
tube increases with an increase in the viscosity of the formulation. For
less viscous solutions the inner diameter ranges from 0.12 inch to 0.125
inch. For viscous solutions the inner diameter is 0.195 inch.
Generally the actuator, stem, housing and dip tube are made up of
plastic. The mounting cup and spring made up of metal. The gasket made
up of rubber or plastic resistant to the formulation.
Actuators:
 It ensures that aerosol product is delivered in the proper and desired
form.
 It allows easy opening and closing the valve.
 The actuator or adaptor which is fitted to the aerosol valve stem is a
device which on depression or any other required movement opens the
valve and directs the spray to the desired area.
 The design of the actuator which incorporates an orifice of varying size
and shape and expansion chamber is very important in influencing the
physical characteristics of the foam or spray. Particularly in the case of

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inhalation aerosols, the active ingredient/s must emit with proper
range of particle size.
 A proportion of the active ingredient/s is usually deposited on the inner
surface of the actuator and the amount available is less than the
amount released by actuation of the valve.
 Following types of actuators available.
Types of actuators
a) Spray actuators: These are having capable of dispersing the stream
of product concentrate and propellant into relatively small particles by
allowing the stream to pass through various openings 0.016 to 0.040
inches. It breaks stream into fine particles.
These actuators used for topical use such as spray-on bandages,
antiseptics, local anesthetics and foot preparations.
(c)Foam actuators: It consists of relatively large orifices ranges from
0.070 to 0.125 inches.
c) Solid steam actuators: Similar to foam type of actuators. Used for
semisolid products like ointments.
d) Special/ Mist actuators: These are designed for special purpose, to
deliver the contents of medicaments at site of action like throat, eye or
vaginal tract.

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Manufacturing or Formulation and Filling of Aerosols
The manufactured aerosols can be filled in to the containers can be done
by following methods and apparatus used.
a) Cold filling Apparatus
b) Pressure filling apparatus
c) Compressed gas filling apparatus
d) Rotary filling machine
a) Cold filling apparatus: Cold filling apparatus consists of an
insulated box which fitted with copper tubings and filled with dry ice or
acetone. The fitted copper tubings increase the surface area and cause
faster cooling. The hydrocarbon propellant is not to be stored in the
copper tubings as it might cause explosion.
(b)Pressure filling apparatus: Pressure filling apparatus consists of a
metering burette capable of measuring the amount of propellant to be
filled to the container. The mixture of propellant or propellant/s are
added through the inlet valve present to the bottom of the valve under
its own vapor pressure. A cylinder of nitrogen or compressed gas is
attached to the top of the valve and the pressure of nitrogen causes the
propellant to flow to the container through the metering burette. The
propellant flows to the container stops when the pressure of the flowing
propellant becomes equal to the pressure of the container.

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(c)Compressed gas filling apparatus: A compressed gas propellant
is used. As the compressed gas is under high pressure, so the pressure
is reduced by pressure reducing valve. A pressure of 150 pounds per
square inch gauge is required to fill the compressed gas propellant in
the aerosol container. The product concentrate is placed in the pressure
gauge and the valve is crimped in its place. The air is evacuated. The
filling head is inserted into the valve opening. Upon the depression of
the valve, the compressed gas propellant is allowed to flow into the
container. The compressed gas stops flowing when the pressure of the
compressed gas flowing to the container from the burette becomes equal
to the pressure within the container. In case of increasing the solubility
of the gas in the product concentrate and also when an increased
amount of compressed gas is required, carbon dioxide and Nitrous
dioxide is used. The container is needed to be shaken during and after
the filling operation to enhance the solubility of the gas in the product
concentrate.
(d)Cold filling method: Two different methods are involved: The
aerosol product is filled into the container is by two methods:
 In the first method, the product concentrates are chilled to a
temperature of - 30 to - 400 F. The chilled product concentrates are
added to the chilled aerosol container. The chilled propellant is added
through an inlet valve present under side of the valve of the aerosol
container.

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 In the second method, both the product concentrate and the propellant
are chilled to - 30 to - 400 F. Then the mixture is added to the chilled
container.
In both the above methods, after the aerosol containers are filled, the
valves are set in its place and the filled aerosol containers are passed
through a water bath in which the contents of the containers are heated
to 130 0F to test for leaks and strength. After checking the containers
apply air drying, cap it and label it.
Cold filling method is advantageous for the filling of metering valve
containing aerosol container. The pressure filling method is more
prominent than cold filling method as most of the formulations cannot be
cooled to very low temperatures.
Pressure filling method:
The product concentrate is filled to the aerosol container through the
metering pressure filling burette at room temperature. The propellant is
added through the inlet valve located at the base of the valve or under
the valve after the crimping of valve. The flow of propellant to the aerosol
container continues till the pressure of the filling propellant becomes
equal to the pressure within the container. The aerosol container are
capped and labelled.

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A. Method-1
- The product concentrate is added to container at room temperature.
- The valve crimped into place.
- The propellant is then added under pressure through the valve stern
or through the actuator and around the sealing gaskets.
B. Method-2
- Under the cap method: product concentrate is added to the container
and valve place in a position.
- A seal is formed around the shoulder of the container and using a
vacuum, the valve cup is raised slightly from the can and propellant is
added.
- The valve is then crimped into the place.
This method is more prominent than cold filling method as most of the
formulations cannot be cooled to very low temperatures.
(e)Rotary filling machine: The pressure filling method is first slower
than cold filling method. With the development of newer technique the
speed of pressure filling method was increased. The concentrate is added
to the container at room temperature, and the valve is crimped in place.
The propellant is added through the valve or "under the cap". Since the
vacuum contains extremely small openings (0.018 to 0.030 inches), this
step is slow and limits production. With the development of new rotary
filling machines for aerosols and newer filling heads, which allows
propellant to be added around and through the valve stem.
Advantages of the pressure filling methods compared with cold filling
method:
 The emulsions or suspensions are unstable at very low temperature. At
that time the pressure filling method is the preferred method then that
of cold filling method.
 Here the absence of moisture reduces the chance of contamination.
 The rate of production is high.
 Propellant loss is low.

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Compressed gases filling:
 Here, when the compressed gases are used as the propellant in
aerosol systems, the compressed gas is transferred from large steel
cylinders into the aerosol containers. Before filling, the product
concentrate is placed in the container, then the valve assembly is
crimped into place and the air is removed from the container by a
vacuum pump.
 The compressed gas is then passed into the container through a
pressure reducing valve attached to the gas cylinder; when the
pressure within the aerosol container is equal to the predetermined
rate and setted/ regulated delivery pressure, the stops gas flow and
the aerosol valve is restored to the closed position. Some gases like
carbon dioxide and nitrous oxide (which are slightly soluble in the
product concentrate) the container is manually or mechanically
shaken during the filling operation to achieve the desired pressure
in the head space of the aerosol container.
 For large scale of production Concentrate filler, Valve placer,
Purger and vacuum crimper, Pressure filler, Leak test tank
equipment’s are used.
Quality control tests for Aerosols
Quality control of aerosols include the testing of Testing of Propellant,
Testing of Valves, Actuators and Dip tubes, Testing of Containers,
Weight checking, Leakage Test and Spray Testing/ Spray Pattern.
1) Testing of Propellant/s:
All quality control testing's of propellant/s are accompanied by
specifications. A sample is removed from the container and vapour
pressure is determined which then is compared to specifications. The
density is also checked when necessary.
Other tests include -
 Identification of two or more mixture of propellant/s by Gas
chromatography.
 For propellant purity is checked by moisture, halogen and non-volatile
residue determinations.

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2) Testing of Valves, Actuators and Dip tubes:
Both physical and chemical examinations are done. They are sampled
according to the standard procedures as found in "Military Standard Mil
- STD-105D".A test method was developed for metered dose
pharmaceutical aerosol by Aerosol specifications committee, Industrial
Pharmaceutical Technology section, Academy of Pharmaceutical
Sciences with an objective of determining the magnitude of valve delivery
and degree of uniformity between individual valves.
3) Testing of Containers:
 Metal containers are examined for defects in linings. Several Quality
Control aspects include specifications for degree of conductivity of
electric current as measure of exposed metals.
 For Glass containers examined for Flaws.
4) Weight checking:
Weight checking is done by periodically adding tared to the filling lines
with tared empty aerosol containers. This will check after filling with
product concentrate are removed & re weighed. Same procedure is used
for checking weight of Propellants. It ensures proper blend of the
propellants.
5) Leakage Test:
Leak test is done by checking the crimping of the valve must be available
to prevent defective containers. This is accomplished by measuring the
crimp's dimension and ensuring that they meet specifications. Final
testing of valve closure is done by passing filled containers through water
bath.
6) Spray Testing/ Spray Pattern:
It is to clear dip tube of pure propellant & pure concentrate and to check
for defects in valves & spray pattern.
Packaging, Labeling and Storage
 A unique aspect of pharmaceutical aerosols compared to other dosage
forms is that the product is actually packaged as part of the
manufacturing process. The product is completely manufactured
before itself and then placed in the appropriate container.
 Most aerosol products have a protective cap or cover that fits snugly
over the valve and mounting cup. This mounting cap protects the

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valve against contamination with dust and dirt. The mounting cap,
which is generally made of plastic or metal and also serves a
decorative function.
 Aerosols containers should be maintained with the protective caps in
place to prevent accidental activation of the valve assembly or
contamination by dust and other foreign contents or atmospheric
contents.
 Therapeutic aerosols that are to be dispensed only with prescription
and generally labelled by the manufacturer with plastic peel-away
labels or easily removed paper labels, so that the pharmacist easily
replace the manufacturer's label.
 Safety and precaution labels must warn users not to puncture
pressurized containers and not to use or store them near
heat/temperature or an open flame and not to incinerate them.
 Exposure to temperatures above49°C (120°F) may burst an aerosol
container.
 When the canisters are cold (less than the usual results into spray).
This may be particularly important to users of metered-dose
inhalation sprays.
 For aerosol products are generally recommended for storage between
15°C and 30°C (59°F and 86°F).
CONCLUSION
Many of compounds have been developed using biotechnology and their
delivery to the respiratory system via MDI in an extremely challenging
undertaking.
As chlorofluorocarbon (CFC) propellants cause ozone depletion they are
being replaced with acceptable Hydrofluoric carbons (HFC) propellant.