Aerosols can strongly influence atmospheric circulation, and categorizing it into circulation types (CTs) helps in understanding the relationship between atmospheric forcing and surface
conditions. However, few studies have considered the impact of interactive aerosols on atmospheric
dynamics from a climatic perspective. This contribution aims to assess whether simulations with interactive aerosols (online solving of aerosol–radiation interactions, ARI, and aerosol–radiation–cloud
interactions, ARCI) significantly impact atmospheric dynamics over Europe during winter compared
to conventional regional climate models with prescribed aerosols. For that, Principal Component
Analysis (PCA) has been applied to reduce the dimensionality of the problem in order to cluster
different weather patterns. Results showed significant differences in the two predominant patterns,
characterized by a western zonal flow (CT1) and a low-pressure system centered in Italy (CT2).
The ARI experiment revealed a substantial reduction of surface level pressure over central-eastern
Europe for CT1, resulting in a southward shift of the flux direction, and an increase in pressure over
Scandinavia for CT2. The ARCI experiment exhibited a similar, but weaker effect. Furthermore, the
study demonstrated the impact of aerosols on the frequency of different CTs and on the concentration
of black and white aerosols. The findings of this study emphasize the significant role of aerosols in
the atmospheric system and the need for further research to reduce uncertainty in meteorological
and climatic experiments, particularly in the context of mitigating climate change.
3. INTRODUCTION
Pulmonary drug delivery is primarily used to treat
conditions of the airways, delivering locally acting
drugs directly to their site of action.
The respiratory tract is one of the oldest routes used
for the administration of drugs.
4. ADVANTAGES OF PULMONARY DRUG
DELIVERY
The dose needed to produce a
pharmacological effect can be reduced.
Rapid onset of action.
Avoidance of gastrointestinal upset.
Avoidance of intestinal & hepatic first-pass
metabolism.
5. DISADVANTAGES OF PULMONARY
DRUG DELIVERY
Aerosol devices can be difficult to
use.
Drug absorption may be limited by
the physical barrier of the mucus
layer and the interactions of drugs
with mucus.
6. AEROSOLS
AEROSOLS are the dosage forms containing
therapeutically active ingredients
that are packaged under pressure in a sealed
container
are released as a fine mist of spray upon
activation of a suitable valve system.
1942- First aerosol was developed by
Goodhue and Sullivan.
7. ADVANTAGES
Removal of dose without contamination.
Can be delivered directly to the affected area.
It can produce local & systemic effects.
No manual contact with patient.
Avoid the first pass metabolism.
Faster onset of action.
Irritation can be reduced.
8. DISADVANTAGES
Expensive.
Difficulty in formulation.
Q.C testing is complicated.
Sometimes propellants may cause toxic
reactions.
Highly inflammable.
9. INHALATION AEROSOLS
Airways is unique organ system of body & its structure
allowing air to come into direct contact with blood, so
this is a useful route of administration of drugs in the
inhaled or aerosol form.
The inhalation therapy provides fast acting treatment
for respiratory illness such as asthma & COPD.
10. WHY INHALATION THERAPY ????
ORAL INHALED ROUTE
Slow onset of action Rapid onset
Large dose used Less dose is required
Greater side effects Better tolerated
13. PROPELLANTS
Responsible for developing proper pressure
within the container.
They expel the contents of the container through
valves by applying force.
TYPES OF PROPELLANTS
a) Liquefied gases
b) Compressed gases
14. LIQUEFIED GASES
They are widely used in the
formulation of aerosols because they
are very effective in dispensing the
active ingredients into a fine mist.
They are relatively inert, non-toxic &
non flammable.
They also have the advantage of
maintaining a constant pressure
within the container.
15. Liquefied gases are of 3 types
Liquefied
gases
Chlorofluorocarbons
(CFCs)
Hydrochlorofluorocarbons
(HCFCs)
Hydrocarbons (HCs)
16. CHLORO FLUORO CARBONS
Propellant of choice for oral and inhalation.
Examples-
Trichloromonofluoromethane – Propellant 11
Dichlorodifluoromethane – Propellant 12
Dichlorotetrafluoroethane – Propellant 114
17. HYDRO CHLORO FLUORO CARBONS
These compounds break down in the atmosphere at
faster rate than CFCs.
Examples-
Heptafluoropropane (HFA – 227)
Tetrafluoroethane (HFA – 134a)
Difluoroethane (Propellant 152a)
18. HYDROCARBONS
Can be used for water based aerosols and topical
use.
Examples –
Propane (Propellant A-108)
Isobutane (Propellant A-31)
Butane (Propellant A-17)
19. COMPRESSED GAS PROPELLANTS
Compressed gas propellants occupy the
head space above the liquid in the can.
When the aerosol valve is opened the
gas ‘pushes’ the liquid out of the can.
The amount of gas in the headspace
remains the same but it has more space,
& as a result the pressure will drop
during the life of the can.
EXAMPLES- Carbon dioxide, Nitrous
Oxide, Nitrogen.
20. CONTAINERS
Various types of materials are used in the
manufacture of aerosol containers.
Which must withstand pressures as high as 140 to
180psig at 130°F.
TYPES OF MATERIALS USED-
A. Metal
B. Glass
22. GLASS
Two types of glass containers are used.
1) Uncoated glass
2) Plastic-coated glass
23. VALVES
The modern day aerosol
valves are multifunctional.
The materials used in the
construction of the valve must
be approved by FDA.
The valve is expected to
deliver a given amount of
medication.
25. Continuous spray valve
Used for topical aerosols.
Valve components-
Ferrule or Mounting cup
Valve body or Housing
Stem
Gasket
Spring
Dip tube
26. Metering valves
Metering valves are
applicable to the
dispensing of potent
medication.
Approximately 50 to 150mg
±10% of liquid material can
be dispensed at one time
with the use of such valves.
27. ACTUATORS
These are specially designed buttons which helps in
delivering the drug in desired form, i.e., spray, wet
stream, foam or solid stream.
29. CONCLUSION
Pharmaceutical aerosol is a noninvasive
pulmonary drug delivery system which is
considered to be one of the best methods as
compared to other routes of administration.
Its advantages over the other route of
administration enhance its wide range of
application in the treatment of illness
including asthma, chronic obstructive
pulmonary diseases (COPD) etc.
30. Continue……..
Some of its advantages include the possibility
of directly targeting the drug to the site of
action, avoidance of first pass metabolism,
rapid action and also reduction of systemic
side effects etc. Hence pulmonary route of
administration can be successful in the
research field in near future.
31. REFERENCES
• Nimesh P.Patel, Arpan A. Patel & Moin K.
Modasiya. Review on: Aerosols- Pulmonary Drug
Delivery System. International Journal of
Pharmaceutical and Chemical Sciences 2012;
1(1): 19-24.
• Lahkar Sunita. An Overview on: Pharmaceutical
Aerosols. International Research Journal of
Pharmacy 2012; 3(9): 68-75.
• Lachman/Lieberman’s. The Theory and Practice
of Industrial Pharmacy: Pharmaceutical
Aerosols, 4th Edition: 770-778.