This is about the large extraction, hope you all get benefit from this and feel easy to use it . This is all about how we do extraction at large scale and what is the best procedure to do it properly, as a pharmacist we must know about little details of our formulations how they are extracted and their further process and machinery used. All the terms should be considered and handling is the most important step. This will be a ready to explain type information.

1. LARGE SCALE EXTRACTION
Submitted by: Anum Fatima

2. CONTENT
⦁ Introduction
⦁ Definition of extraction
⦁ Purpose of extraction
⦁ Marc and menstruum
⦁ Choice of menstruum
⦁ Solvents of extraction
⦁ Factors for selecting solvents
⦁ Methods of large scale extraction

3. INTRODUCTION
Although, the various classes of preparations involving simple
expression, aqueous hot and cold extraction and evaporation
were in
vogue since long time but, real and scientific rapid progress in
the
extraction procedures for medicinal plant's preparations was
made
after the 19th century.

4. DEFINITION
The process of isolation of active ingredients or active substances
or active medicaments from raw materials of either plants or
animals or directly from
natural sources with the help of solvent is called extraction.
OR
The removal of desired soluble constituents from a substance
leaving out those which are unwanted with the aid of solvent is
called Extraction.

5. EXAMPLE
• Making Tea
Water is placed in contact with tea bags and the "tea" is extracted
from the tea leaves into the water. This works because the "tea"
is soluble in water but the leaves are not.

6. PURPOSE OF EXTRACTION
⦁ To obtain the therapeutic portion of dosage from raw materials and to
eliminate the unwanted or inert material by treatment with solvent
⦁ They play a decisive role in the determination of qualitative and
quantitative composition of extracts
⦁ The extracts obtained are also utilized for the isolation and
characterization of therapeutically active chemical constituents.

7. GENERAL TERMS
• Marc:
• The unwanted or insoluble substances left behind after the process of
extraction is called marc. These are not used for further purpose in the
process of extraction.
• Menstruum:
• The solvent used in the process of extraction is called solvent. The
most commonly used menstruum is water.

8. CHOICE OF SOLVENTS MENSTRUUM:
The menstruum should have the following properties:
1. Highly selective for the compound to be extracted
2. High capacity of extraction
3. Should not react with the extracted compound or any other
compound in the raw material.
4. Should have low price and easily available
5. Should be harmless to man and environment
6. Completely volatile

9. SOLVENT AND METHOD OF
EXTRACTION
Solvents
The solvents play an important role in
the method of extraction. The main
solvents used in the process of
extraction are:
1. Water
2. Alcohol
3. Ether
4. Chloroform
5. Light petroleum
Methods
⦁ Maceration
⦁ Percolation
⦁ Digestion
⦁ Infusion

10. MACERATION
• “The process in which the drug is placed or permitted to soak in
a menstruum for specific period of time until the cellular
structure is softened and penetrated by the solvent and soluble
constituents are dissolves and extracted out.”
For Example:
Tea Bag

11. TYPES OF MACERATION
⦁ Simple Maceration
⦁ Double Maceration
Simple Maceration:
The extraction of the drug with a solvent with several daily
shaking at room temperature. Organized dugs (roots and barks)
are used.
Double Maceration:
The whole of the drug is macerated for 48 hours with the quantity
of the menstruum required for the first maceration. Strain the
liquid and press the marc .Macerate again for 24 hours. Make it
stand for 14 days and filter.
Example:- compounds of Chirata.

12. LARGE SCALE
• Large scale operation demands modification of many extraction
processes.
• In case of jar or vessel containing a small amount of solvent (500 to
1000ml) occasional shaking is no problem. But, for industrial batch
where a large amount of solvent and the vessels having the huge
weight, diameter and height, there will be a considerable difficulty in
shaking the vessels. There are alternative methods of agitation that are
just as effective but much simpler to put into practice. In addition,
economics become increasingly important.
• One of the most important objective is to improve the efficiency of
extraction so that less solvent is needed and evaporation requirements
for concentrated products are reduced. By reducing the cost of
evaporation, it has the further advantage of minimizing the heat
damage to thermo-labile constituents.

13. MODIFIED LARGE SCALE MACERATION
PROCESSES:
Circulatory Extraction:
The efficiency of extraction in a
maceration process can be
improved by arranging for the
solvent to be continuously
circulated through the drug. as
indicated in the Fig
• Solvent is pumped from the
bottom of the vessel to the inlet
where it is distributed through
spray nozzles over the surface of
the drug
(Circulatory Extraction)

14. MULTIPLE STAGE EXTRACTION:
• Like the normal maceration process, however, extraction is
incomplete, since mass transfer will cease when
equilibrium is set up. This problem can be overcome by
using a multistage process. The equipment needed for
this method is a vessel for the drug, together with a
circulating pump and spray distributors, and a number of
tanks to receive the extracted solution. The extractor and
tanks are connected with piping and valves.

15. ADVANTAGES
• The drug is extracted as many times as there are receivers
–in this case, three. If more extraction stages are required,
it is only necessary to have more receivers. The last
treatment of the drug before it is discharged is with fresh
solvent, giving maximum extraction. The solution is in
contact with fresh drug before removal for evaporation,
giving the highest possible concentration.

16. PROCEDURE
Fill extractor with drug, add solvent
and circulate. Run off to receiver
1.Refill extractor with solvent and
circulate. Run off to receiver
2.Refill extractor with solvent and
circulate. Run off to receiver
3.Remove drug from extractor and
recharge. Return solution from 1 to
extractor.

17. EXTRACTION BATTERY
• In the normal percolation process, the percolate is not of maximum
concentration and as such very dilute. The ideal situation would be to
have maximum concentration. Continuous extraction devices of this
type are used where large amounts of single material are handled. It
can be achieved by treating it as a stage wise process. In this process a
series of vessels are used and extraction is semi –continuous.
• Equipments:
• Equipment is described as an extraction battery and consists of a
number vessels with inter connecting pipe work

18. PERCOLATION
The lower is tap opened and the liquid collected there in is allowed to
drip slowly at a controlled rate until volume of the finished product is
obtained.
Types of percolation :
⦁ Simple percolation
⦁ Modified percolation
Simple percolation:
In simple percolation, Drug is imbibe for 4 hours and after that it is
macerate for 24 hours and of the volume of the drug is collected.
Example
Compound texture of cardamom
Modified percolation:
Repeat maceration is more effective than simple maceration. Double
maceration solvent divided into equal multiple time considering the
solvent retained by plant tissue. Use to prepare concentrated preparation

19. MODIFICATIONS OF THE GENERAL
PROCESS OF PERCOLATION
In general process of percolation, particularly in the manufacture
of concentrated preparations like liquid extracts, the following
problems may arise:
a) If the active substances are thermo-labile, evaporation of large
volume of dilute percolate, may result in partial loss of the active
constituents.
b) In the case of alcohol-water mixture, evaporation results in
preferential vaporization of alcohol leaving behind an almost
aqueous concentrate which may not be able to retain the
extracted matter in solution and hence get precipitated.

20. TYPES OF EXTRACTOR
Different Types of extractors used in small scale and large
scale
Extraction. Here we will discuss only large scale extractor.

21. LARGE SCALE EXTRACTOR
• A type of percolator used in
the industrial scale. The drug
is supported on a perforated
metal plate covered with a
layer of sacking or straw. The
percolator is provided with a
removable lid which contains
portholes for packing the
drug, for running in the
solvent and for observing the
flow of solvent.

22. DIGESTION:
• In digestion process the drug is extracted by heating. This
will increase the penetration power of the menstruum so
that there is the complete extraction of the drug. The
apparatus known as “digestor” is used for the extraction of
drug by this method. It is like a pressure cooker. Provide
that temperature doesn’t alter the active ingredients of
plant tissues. The most used temperature are between 35C
to 40C.Temperature shouldn’t exceed more than 50C.

24. INFUSION
• “The process of extracting
chemical compounds or flavors
from plant material in a solvent
such as water, oil or alcohol by
allowing the material to remain
suspended in the solvent over
time”
• Example:- pomegranate infused
water or lime, ginger and mint
infuse water.

25. PROCESS
• The liquid is typically boiled and then poured over the
herb which is then allowed to steep in the liquid for the
period of time. The liquid may then be strain or the herbs
otherwise removed from the liquid creating infusion. The
amount of the herbs left in the liquids depends upon the
purpose for which the infusion is being prepared. Usually
steeping for no more than 15 to 30 minutes.