Volatile oils are concentrated hydrophobic liquids containing aroma compounds from plants. They consist largely of terpenes which are made of isoprene units joined in a head-to-tail fashion. Volatile oils have therapeutic uses as counterirritants, in aromatherapy, and as antiseptics. They are extracted using various methods like steam distillation, solvent extraction, maceration, or enfleurage depending on the plant material.

1. VOLATILE OILS
Shivani-Rawat
B .Pharm[5-Semester]
[U.I.P.S] UTTARANCHAL UNIVERSITY

2. VOLATILE
OILS
An essential oil is
a concentrated
hydrophobic liquid
containing volatile
aroma compounds
from plants. It is
also known as
volatile oil.
Example- clove oil.

3. PLANT PARTS HAVING VOLATILE OIL

4. CHEMISTRY OF VOLATILE OILS
• Many volatile oils consist largely of terpenes.
• Terpenes are defined as natural products whose
structures may be divided into isoprene units.
• These units arise from acetate via mevolonic acid
pathway.
• Isoprenes are 5 carbon compound having 2
unsaturated bond.
• They are joined in head to tail fashion.
• Isoprenes are also termed as hemi-terpenes.

5. PHYSICAL PROPERTIES OF VOLATILE
OILS
• Lighter than water.
• Optically active and high refractive index.
• Do not leave stains like fixed oils.
• Soluble in organic solvents like alcohol ,chloroform.
• Commonly found in the species
-Labiatae
-Rutaceae

6. THERAPEUTIC USES
• As a counter irritant.
• Improves local circulation
• In aroma therapy[e.g. lavender and rosemary]
• Eucalyptus oil administered as an inhalant.
• Antiseptic, antibacterial, antifungal.
• Thymol is used in mouth washes and gargles.
• Reduce secretion of lungs in cough and asthma.

7. EXTRACTION
METHOD
ECUELLE METHOD
Ecuelle method is used for the extraction of
citrus oils where oils cells in rind are
ruptured mechanically using pointed
projections by twisting raw material over
them in clockwise direction either
mechanically or manually.

8. ENFLEURAGE
It is used for extraction of delicate perfumes.
In this method a layer of fat is spread over a
glass plate and flower petal are placed over
fat layer which absorbs volume. The
exhausted petals are replaced by fresh
petals. This process continues till the fatty
layer is saturated volatile principle which is
then extracted with lipid solvent.

9. STEAM DISTILLATION
For substances which are usually injured by
direct heat for example clove, cinnamon.
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
vapour contain oils are introduced in
condensing chamber cooled and collected.

10. MACERATION
The process in which properly communited
drug is placed or permitted to soak in a
solvent for specific period of time until the
cellular structure is softened and penetrated
by the solvent and soluble constituents are
dissolved and extracted out.
Example- tea bags.

11. SOLVENT EXTRACTION
It is used in perfume industry and is an
expensive method,. In this technique parts
containing parts containing volatile oils are
extracted directly by one of the organic solvent as
they are crushed and mixed in the solvent and
are mixed in the solvent and are separated by
distillation.
E.g.-oil of rose

12. CLASSIFICATION OF VOLATILE
OILS