Extraction and Galenical's

1. T Reshma
Assistant Professor
Department of Pharmaceutical Quality
Assurance
Raghavendra Institute of Pharmaceutical
Education and Research

2. EXTRACTION:
➢ It defined as the treatment of the plant or animal tissues with solvent , whereby
the medicinally active constituents are dissolved and most of the inert matter
remains undissolved is known as “Extraction”.
➢ The solvent used for extraction is known as “Menstruum”.
➢ And the inert insoluble material that remains after extraction is called “Marc”.
GALENICAL’S:
➢It is as the preparation methods which are involved in the process of extraction
is known as “Galenical’s”.
➢Such as Infusion, Decoction, Maceration, Percolation and Digestion.

3. EXTRACTION METHODS:

5. MACERATION
➢In this process, the whole or powdered crude drug is laced in a container with
the solvent and allowed to stand at room temperature for a period of at least 3
days with frequent shaking until the soluble matter has dissolved.
➢The mixture is then filtered, the marc is pressed.
➢Various types of Maceration process are involved. They are:
1. Simple Maceration
2. Maceration with Adjustment
3. Multiple Maceration

6. 1. SIMPLE MACERATION
➢A process for tincture made from organised drug such as Roots, Stem, Leaves
etc. This process is called “Simple Maceration”.
Apparatus:
➢A wide mouth bottle or any other container which can be well stoppered is used
for maceration process.
➢A closed container is essential to prevent the evaporation of menstruum which
is mostly concentrated alcohol.
➢No adjustment in volume is made.
Example:
1. Tincture of Orange
2. Tincture of Lemon
3. Tincture of Squill

7. Method:
➢Drug is placed with the whole of the menstruum in a closed vessel for seven
days.
➢During this period shaking is done occasionally.
➢After seven days ,the liquid is strained and marc is pressed.
➢The expressed liquid is mixed with strained liquid.
➢It is then filtered to make a clear liquid.
➢The final volume is not adjusted.

8. 2. MACERATION WITH ADJUSTMENT
➢A process for tincture made from unorganised drugs such as oleo resins and gum
resins. This process is known as “Maceration with Adjustment”.
➢Unorganised drug is placed with 4/5th of the menstruum in a closed vessel for
period of 2-7 days.
➢Shaking is done occasionally.
➢After stated period ,liquid is filtered and final volume is made up by passing
remaining 1/5th of menstruum. The marc is not pressed.
Example:
1. Tincture of tolu
2. Compound tincture of benzoin

9. 3. MULTIPLE MACERATION
➢Process for concentrated preparations which includes both “Double maceration’
and ‘Triple maceration”.
➢Maceration process is carried out in the same way as simple maceration process,
but the menstruum used is divided into two parts in double maceration process
and into three parts in triple maceration process.

10. a. Double maceration process:
➢ Drug is macerated twice by using the menstruum which is divided into parts in
such a manner that the same volume is used for each maceration.
➢ The quantity of menstruum required for two macerations are calculated with
the help below mentioned formula:
Volume of menstruum required for first maceration =
Total vol.of menstruum – Vol.to be retained by drug + Vol. to be retained by drug
2
Volume of menstruum required for first maceration =
Total vol.of menstruum – vol. of menstruum used in first maceration.
maceration

11. ➢In double maceration process, the whole of the drug is macerated for 48 hrs with
quantity of menstruum required for first maceration.
➢Strain the liquid and press the marc.
➢Macerated again for 24 hrs with remaining menstruum required for second
maceration.
➢Strain the liquid and press the marc.
➢Mix the liquid obtained from two macerations and allow it to stand for 14 days
and then filter.
Example:
1. Concentrated Infusion of Orange
2. Concentrated Infusion of Gelatin

12. b. Triple maceration process:
➢In this maceration process, the drug is macerated thrice by using the menstruum
which is divided into three parts in such a manner that the same volume is used
for such each maceration.
➢The quantity of menstruum required for three maceration is calculated as
follows:
Vol. of menstruum required for first maceration=
Total vol. of maceration - vol. to be retained by the drug + vol. to be retained by drug
3
Vol. Of menstruum required for 2 nd &3 rd maceration=
Total vol. of menstruum- Vol. of menstruum used in 1 st maceration
2

13. ➢The whole of the drug is macerated for one hour with a part of menstruum
required for first maceration and strained.
➢Macerate again for one hour with part of menstruum required for second
maceration and strained.
➢Macerate again for one hour with part of menstruum required for third
maceration & strained.
➢Press the marc lightly.
➢Then combine the liquid obtained from second &third maceration &evaporate it
to specified extend.
➢Mix it with liquid obtained from first maceration.

14. ➢Add alcohol 90% equal to 1/4th of the volume of the finished product.
➢Adjust volume with water.
➢Allow it to stand for 14 days and filter.
Example:
1. Concentrated infusion of Quassia.
2. Liquid Extract of Senna.

15. PERCOLATION
➢This is the procedure used most frequently to extract active ingredients in the
preparation of tinctures and fluid extracts.
➢The various percolation processes used for the extraction of drugs. They are:
1. Simple percolation process
2. Percolation processes for concentrated preparation
a. Reserve percolation process
b. Modified percolation process
3. Continuous hot percolation or Soxhlation or Soxhlet

16. 1. SIMPLE PERCOLATION PROCESS
Apparatus:
➢Three types of percolators are used. They are:
a. Conical Percolators:
➢The percolator is made of glass or of metal, usually copper ,which is tinned
inside.
➢It is conical in shape having lower diameter not less than half of upper diameter.
➢There are less chances of choking percolator in case the drug swells up, because
a drug can slope against the wall of the percolator.
a. Conical Percolators
b. Cylindrical Percolators
c. Steam Jacketed Percolators

17. b. Cylindrical Percolators:
➢The percolator is cylindrical in shape i.e. Upper and lower diameters are
same.
➢When a higher concentration of alcohol or any other volatile solvent is used
as menstruum a cylindrical percolator is preferred.
c. Steam Jacketed Percolators:
➢When percolation is a carried is carried at higher temperature ,in order to
increase the solvent action of the menstruum, the percolator is heated by
steam.

18. Method:
➢It consist of downward displacement of
saturated solution formed in maceration and
extraction of the remaining active constituents
present in the drug by slow passage of the
menstruum through the column of the drug.
➢After collecting ¾ of the required volume of
the finished product or when drug is
completely exhausted, the marc is pressed.
➢Mix the expressed liquid with percolate.
➢Add sufficient quantity of menstruum to
produce required volume and then filter. Packing of the Percolator

19. 2. 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:
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.

20. 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.

21. ➢Hence ,more menstruum is required to exhaust the drug when simple percolation
process is used.
➢But if continuous percolation stage has suitable breaks by short maceration
stages, the d/p ratio can be reduced to 1:3.
3. CONTINUOUS HOT PERCOLATION OR SOXHLET
➢When active constituents of the drugs are not freely soluble in the solvent or
difficult to be displaced from the cells of the drug, then it becomes necessary to
extract the crude by the action of hot menstruum for considerable length of
time.
➢The fixed oils from seeds and alkaloids from the drugs are extracted by
continuous hot percolation process using benzene, chloroform, petroleum, Ether
etc.

22. Apparatus:
➢ The apparatus used for continuous hot percolation
process is Soxhlet apparatus which consist of three
parts:
i. Flask, containing the boiling solvent .
ii. Soxhlet Extractor, in which drug to be extracted is
packed. It has side tube which
carries vapours of the solvent from the flask to the
condenser and syphon tube which syphon over the
extract from Soxhlet extractor to the flask .
iii. A condenser, in which the vapours of the solvent
are condensed again into solvent.

23. Procedure:
➢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 placed in the flask and apparatus is then fitted.
➢When solvent is boiled on heating the flask, it gets converted into vapours.
➢These vapours enter into condenser trough the side tube & get condensed into
hot liquid which falls on the column of the drug.
➢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.

24. ➢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.
Limitation of continuous Hot Percolation Process:
1. 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, resin, orange peel etc.
2. Solvent:
➢ only pure solvent or constant boiling mixture can be used for this process.
3. Chemical constituent of the drug:
➢ The process is unsuitable for drugs having thermolabile active constituents
such as enzymes ,alkaloids, anthraquinone derivatives etc.

25. THANK YOU…!