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1. Industrial pharmacy
Extraction
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2. Definition
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 Extraction is the method of removing active constituents from
a solid or liquid by means of liquid solvent.
 The separation of medicinally active portions of plant or animal
tissues from the inactive or inert components by using selective
solvents.

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Types of Extraction

4.  In this extraction the components of the liquid mixture are
separated by contacting them with a suitable insoluble solvent
which preferentially dissolves one or more components.
 Separation of the components from liquid mixture depends upon
the unequal distribution of the components between two
immiscible liquids.
 In this extraction the feed solution is phase 1 and the solvent used
for extraction is phase 2.
 Both the feed and solvent forms a homogenous mixture which is
separated by contacting them with one another to separate out
one of the two liquids preferentially.
 This type of extraction is most widely used to separate actives and
aromatic compounds from plants.
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Liquid-Liquid Extraction (Solvent extraction)

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Liquid-Liquid Extraction (Solvent extraction)

6. Solid phase extraction is used for isolation, enrichment and purification of
components from aqueous solutions depending upon their physical and
chemical properties.
It involves contacting of aqueous samples with a solid phase or sorbent,
where the component under consideration is adsorbed on the surface of the
solid phase prior to elution.
The extract amount is negligible compared to quantity of analyte in the
sample.
This type of extraction is widely used in analytical laboratories.
Solid Phase Extraction
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7. Solid Phase Extraction
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8.  Solid-liquid extraction means the removal of constituents from a
mixture of solids by bringing the solid material into contact with a
liquid solvent that dissolves these particular constituents.
 Leaching may either be used for production of concentrated
solution of an active principle, or in order to free an insoluble
constituents from a soluble material with which it is contaminated.
Solid-liquid extraction
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9. Solid-liquid extraction
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10. Methods of Extraction
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11.  Maceration is a process that involves soaking of plant materials, usually
in powder or coarse form, in a stoppered container with a defined solvent.
 The setup is left to stand at room temperature (+25 “C) for a minimum of
72 hours with shaking.
 The process is conditioned to soften and breakup the plant’s cell wall in
order to liberate the soluble bioactive metabolites.
 After 3 days, the whole mixture is pressed and sieved by filtration using
Whatman no. 1 filter paper.
 In this method, heat is transferred by convection and conduction and the
choice of the solvent is crucial to determine the type of phytochemical
extracted from the samples.
Maceration
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12. Maceration
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13.  This is the most frequently used method to extract phytochemicals for the preparation of
tinctures and fluid extracts.
 A percolator made of a narrow cone-shaped vessel open at both ends is generally used.
 The solid ingredients are moistened with a specified amount of the defined menstruum and
allowed to stand for approximately 4 hours in a closed container.
 The wet mass is then packed and the top of the percolator is closed and some extra
menstruum is added to form a shallow layer above the mass.
 The mixture is allowed to macerate in the closed percolator for 24 hours
 The outlet of the percolator is then opened and the liquid contained therein is allowed to drip
out slowly.
 The percolate is mixed until it measures about three-quarters of the required volume.
 The macerated product is then pressed and the expressed liquid is added to the percolate.
 Properly prepared menstruum is added to produce the required volume, and any excess liquid
is eliminated by filtration or by standing followed by decanting.
Percolation
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14. Percolation
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15. Decoction
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• In decoction, the harvest crude product is boiled in a specified volume of
water for a defined period, cooled and then strained or filtered.
• This procedure is applicable for the extraction of water-soluble, heat stable
metabolites.
• The starting ratio of crude product to water is fixed, such as 1:4 or 1:16.
• The extract is then concentrated to one-fourth of its original volume by
boiling.
• The concentrated extract is filtered and processed further Decoction is
generally suitable for extracting heat-stable compounds in hard plant parts
such as the roots and barks.
• Decoction gives more oil-soluble phytochemicals compared to maceration
and infusion.

16. Decoction
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17. Digestion
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 Digestion is a maceration method that includes application of gentle heat
during extraction.
 It is used when a moderately raised temperature is needed to increase the
efficiency of the menstruum
 In this process drug is extracted by heating at a particular pressure to increase
the penetration power of the menstruum, so that there is complete extraction
of the drug.
 The apparatus used is known as ‘Digestor’ which is a vessel made up of metal.
 The whole of the drug is placed in the covered digestor it and bolted with the
help of nuts.
 The drug is treated with menstruum for a definite period under specified
condition of temperature and pressure.

18. Digestion
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19. Infusion
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 Fresh infusions are prepared by macerating the crude drug for a short period
with cold or boiling water.
 These are dilute solutions of the readily soluble constituents of crude drugs.
 Infusion uses the same principle as maceration; crude drug is soaked in cold
or boiled water for shorter duration.

20. Soxhlet Extraction (Hot Continuous Extraction)
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 In this method, finely ground crude drug sample is placed in a porous bag or
thimble made from a strong filter paper or cellulose, which is placed in
thimble chamber of the Soxhlet apparatus.
 Extraction solvent is heated in the round bottom flask, vaporizes into the
sample thimble, and condenses in the condenser and drip back.
 When the liquid content reaches siphon arm, it is emptied into the bottom
flask again and the process is continued.

21. Soxhlet Extraction (Hot Continuous Extraction)
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22. Microwave Assisted Extraction (MAE)
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MAE utilizes microwave energy to facilitate partition of analytes from the sample
matrix into the solvent.
Microwave radiation interacts with dipoles of polar and polarizable materials
(solvent and sample) that causes heating near the surface of the materials and heat
is transferred by conduction.
Dipole rotation of the molecules induced by microwave electromagnetic disrupts
hydrogen bonding; enhancing the migration of dissolved ions and promotes solvent
penetration into the matrix.
In non-polar solvents, poor heating occurs as the energy is transferred by dielectric
absorption only.
MAE can be considered as selective methods that favour polar molecules and
solvents with high dielectric constant.

23. Sonication Extraction:
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This method involves the use of ultrasound waves ranging from 20 kHz to
2000 kHz.
The mechanic effect of acoustic cavitation from the ultrasound waves
increases the surface contact between solvents and samples and permeability
of cell walls.
Physical and chemical properties of the materials subjected to ultrasound are
altered and disrupt the plant cell wall; facilitating release of compounds and
enhancing mass transport of the solvents into the plant cells.
The procedure is simple and relatively cheap that can be used in both small
and larger scale of phytochemical extraction.

24. Accelerated Solvent Extraction (ASE)
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ASE is an efficient form of liquid solvent extraction due its minimal solvent
requirement.
Sample is packed with inert material such as sand in the stainless steel
extraction cell to prevent sample from aggregating and block the system
tubing.
Packed ASE cell includes layers of sand-sample mixture in between cellulose
filter paper and sand layers.
ASE is an automated extraction technology capable of controlling
temperature and pressure for each individual samples and completes in less
than an hour.

25. Supercritical Fluid Extraction (SFE)
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Supercritical fluid (SCF; dense-gas) is a substance that shares the physical
properties of both gas and liquid at its critical point.
SCF behaves more like a gas but have the solvating characteristic of a liquid.
A major drawback of this method is the initial cost of the equipment which is
very high.

26. Applications of Extraction
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It is used in the separation of antibiotics and protein recovery.
It used to recover high-boiling components such as phosphoric acid, boric
acid, and sodium hydroxide from aqueous solutions.
It is used to obtain therapeutically active constituents from plant parts and to
eliminate the inert material
It is used to isolate enzymes (renin) and hormones (insulin) from animal
sources.
Gelatin is produced by conversion of skin and bone collagen by treatment
with lime or diluted acid and is further extracted with warm water.
It is used in extraction of fixed oils from seeds.

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