Volatile oils are products which are generally complex in composition, consisting of the volatile principles contained in plants. The odorous, volatile principle of plant source are known as volatile oil.” They are also called as essential oils because they represent essence of active constituents of the plant. As they evaporate when exposed to air at ordinary temperature, they are also called as ethereal oil.

1. VolatileOil
Chepter-4
D. Pharm 1stYear

2. INTRODUCTION
“Volatile oils are products which are generally
complex in composition, consisting of the volatile
principles contained in plants. The odorous, volatile
principle of plant source are known as volatile oil.”
 They are also called as essential oils because
they represent essence of active constituents of
the plant.
 As they evaporate when exposed to air at
ordinary temperature, they are also called as
ethereal oil.

3. CLASSIFICATION
OF
VOLATILE
OIL

4. OCCURRENCE:
 Volatile oils are present in entire plant or in any part of the plant.
 They are secreted in special structure such as duct, cell,
lysigenous gland, trichomes (hair-like structure).
 Lighter than water
 Possess distinct odours
 Commonly found in the family like, Labiatae, Rutaceae,
piperaceae, zingiberaceae, umbelliferae, myrtaceae, lauraceae
 They are present in entire plant or in any part of the plant
 Don't leave stains like fixed oils
 Insoluble with water and soluble in organic solvents like ether,
alcohol, chloroform, ethanol etc.
 They should be stored in a cool, dry place in tightly stoppered.

5. Distribution
 Glandular hair in Labiatae
 Modified parenchyma cells in Piperaceae
 Special tubes or oil tube in pericarp of fruits of
umbelliferae
 Lysogenous and schizogenous cavities in
Rutaceae
 In the conifers ,volatile oil may occur in all tissues
 Petals of rose
 Bark of cinnamon
 Fruit of coriander
 Leaves of pepper mint

6. ISOLATION
1.Distillation
a.Distillation With Water
b.Distillation With Steam
c. Water & Steam Distillation
2.Expression (Ecuelle Method)
3.Extraction
a.Extraction with Volatile Solvents
b.Enfleurage Method

7. 1.Distillation with water
 The crude drugs are distilled with water by using Clevenger
apparatus.
 It is applied to plants which are not injured upon boiling.
 Crude drug is introduced into the distillation chamber along
with water and subjected to heat below 40 C.
 A mixture of oil and water is obtained as a distillate which is
collected in a Florentine flask.
 The distillate is separated into two layers oil being withdrawn
through the upper outlet of the condenser and water from
the lower outlet or vice versa in case of clove as clove oil is
heavier than water.
 E.g. Clove, sandal wood, cinnamon etc. are extracted by this
method.

8. 2. Distillation with Steam
 For substances which are usually injured
by direct heat and boiling.
 Take some water in a tank subjected to
heat.
 Take the plant part which contain volatile
oil in a other tank but it connect with the
water tank.
 Steam is passes through the crude drug,
steam is generated by another chamber
and piped into container having drug.
 The vapor contain vol oils are introduced in
condensing chamber cooled and collected.

9. 3. Water & Steam Distillation
 For substances which are usually injured by direct heat.
 Dried drug ground and covered with layer of water.
 Steam is passes through mixture, steam is generated by another chamber and piped into
container having drug.
 The vapor contain vol oils are introduced in condensing chamber for cooled and collected.

10. 4. Expression (Ecuelle Method)
 Ecuelle method is used for the extraction of
citrus oil.
 Where oils cells in rind are ruptured
mechanically using pointed projections by
twisting raw material over them in clockwise
direction either mechanically or manually.
 Then the fruit rupture are pressed with
hydraulic platform using high pressure.
 Solid from the oil is then separated from the
juice by centrifugation.
 The emulsion is treated in a centrifuged
where essential oil being lighter is separated
from water.

11. 5. Extraction withVolatile Solvents
 Fresh flowers are transferred into specially constructed extractors at room temperature and
carefully treated with purified solvent usually petroleum ether.
 The solvent penetrates the flowers and dissolves the natural perfume together with some
waxes and other albuminous and coloring matter.
 This solution is pumped into an
evaporator and concentrated at
low temperature. After complete
evaporation of solvent the flower
oil is obtained.
 This method is used in perfume
Industry.

12. 6. Enfleurage Method
 Enfleurage method is used for extraction of
delicate perfumes.
 In this method , The drug containing volatile oil
is spread on glass sheet, which is arranged in
vertical wooden frame.
 The fat absorbs volatile oil constituents.
 The fat containing volatile oil is known as
pomade which is collected.
 The volatile oil is extracted from the pomade
using alcohol. For example, Oil of rose.

13. Identification

14. THERAPEUTIC
ACTIVITY
Therapeutic activities of volatile oils are:
 As a counter irritant
 Eucalyptus oil administered as an inhalant.
 Improves local circulation
 As carminative (relive gas), shows anti-spasmodic.
 Thymol is used in mouth washes and gargles
 Local an anesthetic
 Reduce secretion of lungs in cough and asthma.
 Antiseptic, anti bacterial, anti fungal
 Anti helminthes
 Also used in aroma therapy (eg. lavander, rosemary)

15. PHARMACEUTICAL
APPLICATION
 Perfume & cosmetic Industry
 Masking agent in cleaning mixtures
 Polishes & insecticides
 Flavours for foods & confections (elaborate
sweet/delicacy)
 As starting material for synthesis of other
compounds