e-content of extraction for M.pharm students.

1. EXTRACTION
Presenting by,
Mr Purushotham K N
Asst.Professor
Department of Ph.Chemistry.
SACCP,B.G.Nagara
2022-2023
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2. CONTENTS
Introduction
Various Methods
Liquid Extraction
Extraction with Reflux
Extraction with Agitation
Counter current Extraction
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3. Introduction
o Unit operations involved a physical change or chemical transformation such
as separation, crystallization, evaporation, filtration, polymerization,
isomerization, and other reactions.
o Some important unit operations carried in chemical industries
are: Distillation, Drying, Evaporation, Gas Absorption & Desorption, Liquid-
Liquid Extraction , Solid-Liquid Extraction (Leaching) , Crystallization
Adsorption.
o In the extraction process, a solute is transferred from one phase to another to
separate it from unreacted starting materials or impurities.
o Extraction is also used to facilitate the isolation of a solute from a reaction
solvent that is difficult to remove by evaporation, such as a solvent with a high
boiling point.
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4. EXTRACTION
PROCESS
Infusion
Fresh Infusion
Concentrated
Infusion
Decoction Maceration
Simple Maceration
Maceration with
adjustment
Multiple
Maceration
Percolation
Simple
Percolation
Percolation
Process For
Concentrated
Preparation
Reserve percolation
process
Modified
Percolation
Process
Continu
ous
Percolat
ion
Process
Digestion
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5. Infusion
 It consists of pouring water over the drugs and then allowing it to keep in
contact with water for the stated period, usually 15 minutes, with occasional
stirring and finally filtering off the liquid.
 The marc is not pressed.
 Marc is the unwanted or insoluble substances left behind after the process
of extraction.
 The boiling water is commonly used as a solvent, since it has a greater
solvent action than cold water.
 After the specified time the liquid is filtered and dispense as drug .
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6.  Fresh infusions are prepared by macerating the crude drug for a short
period of time with cold or boiling water.
 These are dilute solutions of the readily soluble constituents of crude
drugs.
 Concentrated infusions are prepared by modified percolation or
maceration process, which after dilution with water, resemble in potency
and aroma the corresponding fresh infusion.
 Concentrated infusions are especially prepared in which the active
and desirable principles of drug are equally soluble in water or in the
menstruum used for both concentrate and infusions.
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7. Decoction
In this process, the drug is boiled with water for a stated period usually 10
minutes.
After boiling, the liquid is strained and water is passed through the content
of the strainer to make the required volume.
This process is mainly used for vegetable drugs of hard and woody nature
having thermo stable water-soluble constituents.
The extract from decoction contains a large number of water-soluble
impurities.
A decoction cannot be used for the extraction of thermo labile or volatile
components.
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8. 1 8
 The ginsenosides in ginseng encounter hydrolysis, dehydration,
decarboxylation, and addition reaction during decocting.
 Decoction containing Astragali radix and Angelicae Sinensis Radix.
 And also in these process the hydrolysis efficiency was strongly affected
by pH,temperature and the number of herbs
 And the decoction process might enhance the dissolution of some
bioactive compounds compared with the maceration process.

9. Maceration
 In simple maceration the process solid ingredients are placed in a
stoppered container with the whole of the solvent and allowed to stand for
a period of at least 3 days (3 - 7 days) with frequent agitation, until soluble
matter is dissolved.
 The mixture is then strained (through sieves / nets), the marc is pressed
and the combined liquids clarified (cleaned by filtration) or by decantation,
after standing.
 In Double maceration process the drug is macerated twice by using the
menstruum which is divided into two parts in such a manner that the same
volume is used for each maceration.
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10. The whole of the drug is macerated for 48 hours with the quantity of
menstruum required for first maceration.
Strain the liquid and press the marc.
Macerate again for 24 hours with the remaining menstruum required
for second maceration.
This is a very simple extraction method with the disadvantage of long
extraction time and low extraction efficiency.
It could be used for the extraction of thermolabile components.
maceration with nearly identical extraction yields, which can be
translated into economic benefits.
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11. Maceration with adjustment
 The unorganized drug is placed with 4/5th of the menstruum in a closed
vessel for a period of 2-7 days.
 During this period, shaking is done occasionally.
 The liquid is filtered and the final volume is made up by passing the
remaining 1/5th of the menstruum through the filter.
 The marc is not pressed.
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12. 1 12
Double maceration process
 The drug is macerated twice by using the menstruum which is divided
into two parts in such a manner that the same volume is used for each
maceration.
 The whole of the drug is macerated for 48 hours with the quantity of
menstruum
required for first maceration.
 Strain the liquid and press the marc.
 Macerate again for 24 hours with the remaining menstruum required
for second maceration.
 Mix the liquids obtained from the two maceration and allow to stand for
14 days and filter.

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Triple maceration process
 The drug is macerated thrice by using menstruum which is divided into
three parts in such a manner that the same volume is used for each
maceration.
 The whole of the drug is macerated for one hour with each part of
menstruumand strained.
 Combine the liquids obtained from second and third maceration and
evaporateand mix it with the liquid obtained from firstmaceration.
 Add alcohol 90% equal to 1/4th of the volume of the finished product
and adjust with water.
 Allow to stand for 14 days and filter.

14. Percolation
 Percolation is more efficient than maceration because it is a continuous
process in which the saturated solvent is constantly being replaced by fresh
solvent.
 Compared the percolation and refluxing extraction methods to extract
Undaria pinnatifida.
 They found that the contents of the major component, fucoxanthin4, from
the percolation extraction method were higher than that from the refluxing
method while there was no significant difference in extract yield between the
two methods.
 Used the whole alkaloids content determined by acid-base titration as the
index and optimized.
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15. Ethanol percolation method by soaking the medicine with 55% alcohol for 24
h and then percolating with 12 times the amount of 55% alcohol.
Percolation Processes for concentrated preparation.
Percolation processes for concentrated preparation are used for preparing
liquid extracts and solid extracts. The various processes used for the preparing
concentrated preparations are:
 Reserve percolation process
 Modified percolation process
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16. A) Reserve percolation process
In this process, a part of the percolate, generally ¾ volume of finished
preparation, is reserved
Then the percolation process is continued till the drug is completely exhausted.
The percolate is subjected to evaporation or distillation to convert it into a soft
extract.
This soft extract is dissolved in the reserve portion of percolate & then
sufficient menstruum is added to produce required volume.
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17. B) Modified Percolation Process
 In percolation process for preparation of tincture, the drug/percolate (d/p)
ratio is about 1:4.
 The d/p ratio is reduced to 1:3 by modifying percolation process & hence
there is lot of saving in heat, time & menstruum.
 Percolation is a displacement process.
 The strong solution of active constituents of drug formed during
maceration is displaced by a fresh menstruum when percolation process is
started.
 It is proved that stationary menstruum (menstruum remaining in contact
with drug) dissolves more matter than flowing menstruum. Hence ,more
menstruum is required to exhaust the drug when simple percolation process is
used.
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18. Simple Percolation
 It is continuous downward displacement of the
solvent through the bed of crude drug material
to get extract.
 Most frequently used to extract active
ingredients in the preparation of tinctures
and fluid extracts.
 It is the method of short successive maceration or
process of displacement.
 A percolator (a narrow, cone-shaped vessel open
at both ends) is generally used conical
cylindrical.
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19. 1 19
Steps involved in percolation
 Size reduction: The drug to be extracted is subjected to suitable
degree ofsize reduction, usually from coarse powder to finepowder.
 Imbibition: During imbibition the powdered drug is moistened with a
suitable amount of menstruum and allowed to stand for four hours in a well
closedcontainer.
 Packing: After imbibition the moistened drug is evenly packed into the
percolator.
 Maceration: After packing sufficient menstruum is added to saturate the
material. The percolator is allowed to stand for 24 hours to macerate the
drug.
 Percolation: The lower tap is opened and liquid collected there in is
allowed to drip slowly at a controlled rate until 3/4th volume of the
finished product isobtained.

20. Continuous Percolation Process
 This also known as Soxhlet extraction.
 This process is done for those drugs in which percolation of
menstruum into cellular tissues is very low.
 In this process the drug to be extracted is packed in a paper
cylinder made from a filter paper & it is placed in the body of
Soxhlet extractor.
 The solvent is boiled on heating the flask, it gets converted
into vapours.
 These vapours enter into condenser through the side tube &
get condensed into hot liquid which falls on the column of the
drug.
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21.  When extractor gets filled with the solvent, the level of syphon tube
also raises up to its top.
The solvent containing API in the syphon tube syphon over & run into
the flask, thus emptying the body of extractor.
This altering of filling and emptying the body of extractor goes on
continuously.
This process is repeated until drug is exhausted.
The process is repeated about 15 times for complete exhaustion of the
drug.
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22. Limitation of continuous Hot Percolation Process:
 Physical character of the drug : The physical character of the drug is such
that it would block the Soxhlet apparatus in case it is used for its extraction
by this method.
E.G opium , gum, orange peel etc
 Solvent : only pure solvent or constant boiling mixture can be used for
this process.
 Chemical constituent of the drug: The process is unsuitable for drugs
having thermolabile active constituents such as enzyme alkaloids,
anthraquinone derivatives.
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23. Digestion
 The drug is extracted by heating at a particular pressure.
 The apparatus known as “Digestor” is used for extraction of the drug by this
method.
 It is a vessel made up of metal.
 The whole of the drug along with menstruum is placed in the body of the
digestor.
 Place the cover over it and bolt it with the help of nuts.
 The drug is treated with menstruum under specified conditions of
temperature and pressure.
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24. Liquid-Liquid Extraction
In liquid-liquid extraction two components in solution are separated by
their distribution between the two immiscible phases with the addition of a
third component.
 Solvent or the entrainer is the liquid added to the solution for the
extraction process.
 This solvent takes up part of the components of the original solution and
forms an immiscible layer with the remaining solution.
 Extract is the solvent layer and the other layer composed of the
remaining original solution plus the solvent left is called the raffinate.
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25. o Petroleum industry extensively uses the
liquid liquid extraction process in
separating hydrocarbons.
o The knowledge of liquid-liquid
equilibrium (LLE) is necessary for design
and optimization of a new separation
process.
Liquid-Liquid Extraction
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26. Extraction with Reflux
o A mixture of reactants and solvent is placed in a suitable vessel, such as a
round bottom flask.
o This vessel is connected to a water-cooled Liebig or Vigreux condenser,
which is typically open to the atmosphere at the top.
o The reaction vessel is heated in order to boil the reaction mixture;
vapours produced from the mixture are condensed by the condenser, and
return to the vessel through gravity.
o The purpose is to thermally accelerate the reaction by conducting it at an
elevated, controlled temperature (i.e. the solvent's boiling point) and
ambient pressure.
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27. Ethanolic Heat Reflux Extraction (EHRE )
 A sonicator bath (Powersonic 410, Hwashin Technology Company,
Gyeonggi, Korea) was used for 30 minutes at each treatment prior to the
extraction.
 The sonication process was carried out for each four 500-ml Erlenmeyer
containing 250 ml of ethyl alcohol and 50 g of dried tobacco powder.
 Internal dimension of sonicator bath is 30 x 24 x 15 cm, with frequency of
40 kHz and operated at room temperature.
 Four 500-ml three-neck rounded flasks were prepared for ethanolic heat
reflux extraction (EHRE).
 A mixture of tobacco powder and solvent in each Erlen Meyer after
completion of the sonication process was then poured into the flask.
 The EHRE durations for the different flasks were 2, 4, 6, and 12 hours.
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28.  The EHRE durations for the different flasks were 2, 4, 6, and 12 hours.
 The temperature of all flasks was set at the solvent’s boiling point (75–78°C),
and agitation was set at 150 rpm.
 This step was carried out in triplicate; it was then followed by the recovery
process.
 Ethylene glycol as a condenser coolant (with cooling temperature to 0°C) was
used to condense vapor compounds back to the flask.
 This will certainly have implications on the cooling results.
 The ethyl alcohol that evaporates with volatile compounds therein will be more
easily condensed and flows back into liquid form.
 Ethylene glycol with the formula (CH2OH)2 is known as a condenser coolant
that can be applied in EHRE chiller system.
 Pure ethylene glycol has a freezing point of about -12°C; it is lower than water
that is only 0°C . 28

29. Extraction with agitation
 Agitation extraction of green tea metabolites was carried out using a shaking
water bath (JSSB-50T, 3.2 KW, 14.5 A 1P, JS Research Inc., Gong Ju, South
Korea), at 100 rpm.
 As described above, 100 mL of double distilled water (60, 70, and 80 °C)
was poured over 1 g of grounded green tea leaf powder into a 250 mL conical
(Erlenmeyer) flask.
 Then the flask was placed in the shaking water bath at specific temperatures.
Samples were taken at 5, 10, 15, 20, 25 and 30 min, filtered through Whatman
No. 1 filter paper, and cooled at room temperature (25 °C).
 Extraction volumes were maintained during both ultrasonic and agitation
extraction techniques with double-distilled water, and flasks were covered with
aluminum foil to avoid loss of material.
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30. Counter Current Extraction
 Counter current extraction is a method of multiple liquid-liquid extraction.
 Separation of components having variable solubility in two immiscible liquid
phases is achieved.
 In the counter current extraction two immiscible solvents flow in an opposite
direction in multiple stages, (after several stages pure A and B solvents can be
obtained)in liquid-liquid extraction the solvent is used to extract another liquid
phase.
 To distribution of active principle between water and organic solvent depends
on the hydrophilic groups present in the constituent molecules.
 If hydrophilic groups are ionisable , PH will be an important factor.
 If ionisation constants of isomers are different then separation can be
achieved.
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31. Craig apparatus
A method of multiple liquid-liquid extractions is counter current extraction,
which permits the separation of substances with different distribution
coefficients(ratios), A clever design known as Craig apparatus is used for this
purpose.
A simple types of apparatus scale is a Craig apparatus which it consists of a
series of glass tubes (r:0,1,2,) that are designed and arranged such that the
lighter liquid phase is transferred from one tube to the next.
The lower(heavier) phase of the two-phase solvent system (e.g. water) is the
“stationary phase’’, whereas the upper (lighter) phase (e.g. hexane) is the
‘‘mobile phase”.
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32. 1 32
 The material to be extracted is moved in one direction (generally in the
form of fine
slurry) within a cylindrical extractor where it comes in contact with
extraction solvent.
 Finally, sufficiently concentrated extract comes out at one end of the
extractor while the marc falls out from the other end.
A manually operated Craig apparatus consisting of 25tubes

33. References
R M Mehta .Pharmaceutics 1
Sukhdev Swami Handa, Suman Preet Singh Khanuja, Gennaro Longo, Dev
Dutt Rakesh. 2008.
Miljanović A, Bielen A, Grbin D, Marijanović Z, Andlar M, Rezić T, Roca
S, Jerković I, Vikić-Topić D, Dent M. Effect of enzymatic, ultrasound, and
reflux extraction pretreatments on the yield and chemical composition of
essential oils. Molecules. 2020 Oct 20;25(20):4818. as C. Liquid-Liquid
Equilibrium Studies on Extraction of Commercially Significant Carboxylic
Acids (Doctoral dissertation).
Fauzantoro A, Muharam Y, Gozan M. Improvement of nicotine yield by
ethanolic heat reflux extraction of Nicotiana tabacum var. Virginia origin of
ponorogo. International Journal of Applied Engineering Research.
2017;12(23):13891-7. 1 33

34. 1 34
Hidaka R, Wulandari P. Methods of extraction: Maceration, percolation and
decoction. Eureka Herba Indonesia. 2021 Mar 15;2(1):68-74.

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