This document discusses techniques for handling plant extracts, including various extraction methods, factors to consider in the extraction process, types of extracts, and proper handling and storage of extracts. Traditional extraction techniques like maceration and decoction are described alongside newer methods like ultrasonic-assisted and microwave-assisted extraction. Key steps in the extraction process like filtration and solvent evaporation are explained. The document emphasizes controlling extraction parameters and storage conditions to obtain high quality extracts.

1. DEPARTMENT OF PHARMACEUTICAL ENGINEERING
AND TECHNOLOGY,
IIT- BHU
BASIC TECHNIQUES IN HANDLING EXTRACTS
PH- 545
SEPARATION TECHNIQUES OF BIOACTIVES
Presented by-
Anup Kumar Ray
Roll No.- 19162046
M.Pharm. (Pharmacognosy)
1st Semester
Assigned by-
Dr. A.N. Sahu
Associate Professor
Dept. Of Pharmaceutical Engineering And Technology,
IIT-BHU

2. Contents
• Basic introduction
 Terminologies
 Extraction process
• Methods of extraction
 Traditional Methods of extraction
 Novel Methods of extraction
• Points to be considered before extraction
• Types of extracts
• Handling of extracts
• Storage of extracts
• Conclusion

3. INTRODUCTION
 The first medicines known to man were certainly made from locally grown
wild plants.
 Those crude drug contains the active constituents, which can be isolated
from these drugs by various methods of extraction and separation.
If a plant contains several groups of biologically active compounds, it is
not always possible to know which compound is responsible for the activity
and then it is wiser to produce an extract.
Also, different groups of compounds in an extract may have synergistic
effects.
Plant extracts should be standardized to contain a certain amount of one
component or group of components known to possess biological activity.
Plant extracts are used in phytotherapy, whereas extracted, purified
compounds are used in official medicine.

4. INTRODUCTION
Terminologies
1. Marc- Solid residue obtained after extraction.
2. Menstruum- Solvent used for extracting the compound of interest
3. Extract- Solution containing extracted substance after extraction.
4. Extracion- Extraction is defined as the process of isolation of soluble material from an
insoluble residue, which may be liquid or solid, by treatment with a solvent on the basis of the
physical nature of crude drug to be extracted, i.e. liquid or solid, the extraction process may
be liquid—liquid or solid—liquid extraction.
5. Rinsing- Dissolution of extractive substances out of disintegrate cell.
6. Lixiviation- It is the process of separating soluble from insoluble substances by dissolving the
former in water or some other solvent. This process sometimes may also be referred as
leaching

5. INTRODUCTION
Extraction process
The process of extraction is controlled by mass transfer.
Mass transfer is a unit operation, which involves the transfer of mass of soluble
material from a solid to a fluid.
If a crude drug panicle is immersed in a solvent to be used for extraction, the particle
is first surrounded by a boundary layer of the solute; the solvent starts penetrating inside
the particle and subsequently forms solution of the constituents within the cells.
Escape of these dissolved constituents through the cell wall and through the boundary
layer takes place.
The process is continued till equilibrium is set up between the solution in the cells and
the free solution.

6. INTRODUCTION

7. INTRODUCTION

8. INTRODUCTION
The extraction process and
selected factors that impact on
the composition (and quality)
of an extract and the final
product.

9. METHODS OF EXTRACTION
1. Traditional methods
a) Maceration
b) Infusion
c) Decoction
d) Digestion
e) Percolation
f) Alcoholic extraction by
fermentation
g) Enfleurage process
2. Novel methods
a) Ultrasonic-assisted extraction
b) Microwave-assisted
extraction
c) Counter-current extraction
d) Continuous hot extraction
e) Supercritical fluid extraction
f) Pressurised-solvent extraction

10. POINTS TO BE CONSIDERED BEFORE
EXTRACTION
Sample collection parameters,
Suitability of the method of extraction with their
advantages and disadvantages,
Factors affecting extraction process like nature of drug,
Solvent, Temperature, pH, Particle size, etc., &
Choice of solvent for extraction,

11. Contd...
Some examples of solvents for extraction:-
Petroleum ether :- Fixed oils, Phytoglycerols.
Benzene:- Fixed oils, Phytosterols.
Chloroform;- Alkaloids
Acetone:- Phytosterols
Ethanol:- Carbohydrates, Glycosides, Saponin, Phenolics,
Tannins, proteins, Amino acids
Water:- Proteins, Amino acids, Glycosides, Gums, Mucilages,
Carbohydrates

12. TYPES OF EXTRACTS
1. Decoction
2. Infusion
3. Digestion
4. Tinctures
5. Liquid extracts
6. Soft extracts
7. Dry extracts

13. Contd…
Some examples of extracts are:
- Aloe vera: anti-inflammatory.
- Horsetail: diuretic.
- Dandelion: digestive and diuretic.
-Valerian: tranquilizer.
- Ginseng: stress, physical or mental fatigue
-Harpago: anti-inflammatory.

14. Contd …
- Green anise: carminative, diuretic.
- Mint: acidity, gastric pain.
- Echinacea: strengthens the immune system.
- Ginger: nausea.
- Thyme: antiseptic and antifungal properties.

15. HANDLING OF EXTRACTS
While preparing an extract we must know :-
Why are we making an extract?
How are we going to do it?
Which method are we going to choose to get a better yield?
How are we going to control different parameters while making an
extract?
How are we going to remove solid residues from the prepared extract?
How are we going to concentrate our extract if needed?
How are we going to store the extract?

16. HANDLING OF EXTRACTS
Filtration :-
Removing solid particles from liquid in which they are suspended
by preventing their passage through a filter consisting of many small
holes in a rigid membrane.
Examples of filter techniques :-
1. Plate and frame filter press
2. Filter leaf
3. Rotary drum filter

17. HANDLING OF EXTRACTS
1. Plate and frame filter press
The mechanism is surface filtration.
Slurry enters the frame by pressure and flow
through the filter medium.
The filtrate is collected on the plates and sent
to the outlet.
A number of frames and plates are used so
that the surface area increases and consequently
large volumes of slurry can be processed
simultaneously with or without washing

18. HANDLING OF EXTRACTS
2. Filter leaf
It is an apparatus consisting of a
longitudinal drainage screen covered
with a filter cloth.
The mechanism is surface filtration and
acts as sieve or strainer.
Vacuum or pressure can be applied to
increase the rate of filtration

19. HANDLING OF EXTRACTS
3. Rotary drum filter
Rotary drum filter functions on the
principle of filtering the slurry
through sieve-like mechanism on a
rotating drum surface, under the
conditions of vacuum. In addition,
compression, drying and removing
the filter cake (using a knife) are
possible.

20. HANDLING OF EXTRACTS
BLOCKAGE OF FILTER
It is a common problem that occurs in filtration of suspension with
large number of fine particles, due to which pores become blocked
and an impermeable layer of fine particles is formed with a
corresponding drop in flow rate and as a result the filtration will
take longer time.

21. HANDLING OF EXTRACTS
OVERCOMING THE BLOCKAGE OF FILTER BY
BUCHNER FILTRATION SYSTEM

22. HANDLING OF EXTRACTS
Evaporation of solvent
In order to concentrate the extract for chemical or biological
analysis, to remove any solvent traces which may interfere with the
assay or to allow the dry residue to be weighed and stored or
reconstituted in a different solvent for further processing , evaporation
of solvent should be done.
Removal of solvent should be done at as low a temperature as
possible to avoid decomposition of constituents.

23. HANDLING OF EXTRACTS
It can be done by following ways:-
a. Simple evaporation by heating
b. Evaporation under reduced pressure
c. Evaporation with gas stream
d. Freeze drying
e. Vacuum oven

24. HANDLING OF EXTRACTS
Simple evaporation by heating
•Suitable for small scale extraction.
•Place the extaction solvent in an evaporating dish and
gently evaporate the extract over a water bath.
•It is best carried out in a fume cupboard so that evaporating
solvent vapours are led away into an exhaust.

25. HANDLING OF EXTRACTS
Water bath Fume cupboard

26. HANDLING OF EXTRACTS
Evaporation under reduced pressure
A rotary evaporator is a device used in
chemical laboratories for the efficient and
gentle removal of solvents from samples by
evaporation.
It works by increasing the rate of evaporation
of the solvent by :-
(1) Reducing the pressure to lower the solvent
boiling point,
(2) Rotating the sample to increase the effective
surface area, &
(3) Heating the solution.

27. HANDLING OF EXTRACTS
Evaporation with gas stream
•Small amounts of volatile solvents can be
evaporated by blowing a steady stream of inert
gas like nitrogen gas , over their surface.
•It is often useful at the last stage of
fractionation when only few milligrams of
sample may be produced from the solution and
the solution is easily contained in small,
preweighed tube which is final container.

28. HANDLING OF EXTRACTS
Freeze drying
• Freeze drying, also known as lyophilisation or cryodesiccation, is a
low temperature dehydration process that involves freezing the
product, lowering pressure, then removing the ice by sublimation.
• Freeze drying should never be used where there are traces of
organic solvent or volatile oil or bases in the extract as this will cause
deterioration of any rubber tubing and damage to the pump by
dissolving in the lubricating oil.

29. HANDLING OF EXTRACTS
Vacuum oven
•A vacuum (low pressure) environment
has a lower boiling point, allowing drying
treatment at lower temperature for
specimens that cannot be treated by
conventional high-temperature drying.
•O2 inside the chamber can be
eliminated by replacing it with N2 gas,
preventing oxidation during the drying
operation.

30. STORAGE OF EXTRACTS
It depends on how long we wish to store our extract.
(1) We can divide your extract into smaller batches, so that we are not re-
suspending and re-drying the whole lot each time we need some.
(2) We have to reduce moisture (vacuum dessicator), light (UV especially) and
temperature (-20 to -80).
(3) If possible also avoid plastic containers and lids as this may produce
contaminants (phthalates) and store in inert gas (Ar).
(4 Extract should be dried by using rotatory evaporator if organic solvents are
used, after that you can store the extracts in tightly closed container for more
than two years in refrigerator.

31. CONCLUSION
The extraction technique is widely used for the purification of natural
products from both plant and animal source.
After studying about the extract and the process of extraction along
with the method and types of extract we actually learned how to handle
the extract by also studying the different points in extraction handling .
Further the study advances in the isolation and purification techniques
which include chromatographic and spectroscopic evaluation to get
legitimate answers of the questions that arise after the pharmacological
action of extracted drug or chemical compound.

32. THANK YOU