This document discusses the process of collecting and drying crude drugs for phytochemical screening as part of a dissertation. It covers selecting promising plant materials, properly collecting, identifying and drying plants. Extraction methods like maceration, percolation and soxhlation are described. The document emphasizes the importance of using the right solvents and purification methods like fractional crystallization for isolating compounds.

1. Second year M Pharmacy
DESERTATION WORK
2018-2019
Rajiv Gandhi University of Health Sciences, Karnataka, Bengaluru
Collectionand drying of crude drugs
Submitted by
CHANAKYA M R
SUBMITTED TO
SUBJECT INCHARGE
PROF. ITTAGI SHANMUKHA
M. Pharm.,(Ph.D).
Head. Dept. of Pharmacology

2. INTRODUCTION
• The use of plant-derived medicinal dates back many
centuries although it is still under estimation in
modern medicine.
• Plants remain the most important source of natural
drugs. More than 30% of prescription drugs are
natural products.
• More than 60% of anticancer and anti-infective
drugs are natural products.

3. SOURCES OF DRUGS
1.Natural substances: From plants, microorganisms,
animals etc. (totally obtained from nature).
2.Semi synthetic substances: These are drugs that
are manufactured by partial synthesis.
3.Synthetic substances: These are drugs which are
manufactured by total synthesis (i.e. complete
synthetic process or processes)

4. PHYTOCHEMICAL SCREENING
To carry phytochemical screening the following points
must be fulfilled:
1- Selection of promising plant materials.
2- Proper collection of selected plants.
3- Authentication of plant material.
4- Drying of plant materials.

5. 5- Grinding of the dried plants.
6 - Garbling of the dried plants
7 - Packing, storage and preservation
8 - Extraction and fractionation of constituents.
9 - Methods of separation and purification.
10 - Methods of identification of isolated compounds
(Structure elucidation e.g. UV, IR, MS, H-NMR and
C-NMR)

7. SELECTION OF PROMISING
PLANT MATERIALS
• Before investing time, effort and money in
phytochemical screening it is very important to select a
promising plant.
• The choice of promising plant depends upon the
following:
A plant which have a biological activity.
A plant used in folk medicine.

8. MEDICINAL PLANTS INFORMATION
SOURCES
Information, however can be obtained from one or more of
the following sources:
1- Herbals
2- Medical botany
3 - Ethnobotany
4 - Herbaria (herbarium)
5 - Field exploration
6 - Phytopharmacological surveys

9. PLANT IDENTIFICATION
• Identification is a basic activity and one of the
primary objectives of systematics. Although
identification is a separate activity or process, in
practice it involves both classification and
nomenclature. Identification is simply the
determination of the similarities or differences
between two elements.

10. COLLECTION OF
MEDICINAL PLANTS
• Drugs may be collected from wild or cultivated
plants.
• It is known that the active constituents of medicinal
plants are affected by many factors and may vary
during the course of plant growth.
• Proper time of collection is very important to obtain
a drug of a good quality.

16. FACTORS AFFECTING
COLLECTION
1.Time of the year
2.Time of the day
3.Stage of maturity and age
4.External factors

17. DRYING OF CRUDE DRUGS
• Reasons for drying:
1. To help in their preservation.
2. To fix their constituents, by preventing reactions that
may occur in presence of water.
3. To prevent the growth of micro-organisms such as
bacteria and fungi.
4. To facilitate their grinding.
5. To reduce their size and weight.

18. METHODS OF DRYING
• Drying is carried out either by natural or artificial
methods.
1.Natural drying: This is accomplished by natural air
in sun or shade.
2.Artificial drying: This is a rapid method done at
well-controlled temperature and is accomplished by:
a) direct fire.

19. b) Use of heated stones.
c) Use of stoves.
d) Lyophilization (Freeze drying):
• Frozen material is placed in an evacuated apparatus
which has a cold surface maintained at -60 to -80 °C.
Water vapour from the frozen material passes
rapidly to the cold surface.
• It is used for drying heat-sensitive substances e.g.
antibiotics and proteins.

20. CARE TAKEN WHILE DRYING
• Over drying
• Preventing from growth of micro organism
• Proper inspection of the drug
• Time and temperature (Artificial drying)

23. CHOICE OF SOLVENT
• The ideal solvent for a certain pharmacologically
active constituent should:
1.Be highly selective for the compound to be extracted.
2.Have a high capacity for extraction in terms of
coefficient of saturation of the compound in the
medium.
3.Have a low price.

24. 4.Not react with the extracted compound or with other
compounds in the plant material.
5.Be harmless to man and to the environment.
6.Be completely volatile.
Some of major solvents used are:
I. Petroleum ether (60-80) IV. Acetone
II. Benzene V. Chloroform water
III.Chloroform VI. Ethanol (95%)

26. EXTRACTION
• 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.
• In this method the wanted components are dissolved
by the use of selective solvents known as menstrum &
undissolved part is a marc.

27. • After the extraction unwanted matter is removed.
• Extracts are prepared by using ethanol or other
suitable solvent.
• EXTRACT : Extracts can be defined as preparations
of crude drugs which contain all the constituents
which are soluble in the solvent.
• MARC: Solid residue obtain after extraction
• MENSTRUUM: Solvent used for extraction

28. METHODS OF EXTRACTION
• Infusion Decoction
• Digestion Maceration
• Continues hot extraction Percolation
• Supercritical fluid extraction
• Counter current extraction
• Microwave assisted extraction
• Ultrasonication-Assisted Extraction

29. INFUSION : 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.
TYPES OF INFUSION :
• Fresh Infusion : e.g. Infusion of orange
• Concentrated Infusion : e.g. Concentrated
infusion of Quassia

30. • DECOCTION : In this process, the crude drug is boiled
in a specified volume of water for a defined time; it is
then cooled and strained or filtered. This procedure is
suitable for extracting water-soluble, heat stable
constituents.e.g. Tea , Coffee
• DIGESTION : This is a form of maceration in which
gentle heat is used during the process of extraction.
• It is used when moderately elevated temperature is not
objectionable. The solvent efficiency of the menstruum
is thereby increased. e.g. Extraction of Morphine.

31. • MACERATION : In this 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 pressed
and the combined liquids clarified (cleaned by
filtration) or by decantation, after standing.

32. TYPES OF MACERATION
SIMPLE MACERATION: for organized and unorganized Crude
drug
e.g. i) Tincture of Orange
ii) Tincture of Lemon
DOUBLE MACERATION : Concentrated infusion of orange
TRIPLE MACERATION: The maceration process may be
carried out with help of heat or stirring
e.g. i) Concentrated infusion of Quassia
ii) Concentrated infusion of Senna

33. SIMPLE MACERATION: The extraction of the drug with
a solvent with several daily shakings or stirrings at
room temperature. In this type of maceration,
organized drug are used.
TYPES:
1.KINETIC MACERATION:
2.VERTICAL (TURBO) EXTRACTION:

34. • MODIFIED MACERATION: In this type of
maceration unorganized drug are used which have
no cellular or tissue structure. eg. Gum, Resins,
Gum-resins, Oleo gum-resins.
• MULTIPLE MACERATION: It is used to achieve
maximum extraction by using proteins of the total
volume of menstrum for successive maceration.
• VACUUM MACERATION: Designed maceration
vessel with arrangement for connecting it to vacuum
line.

35. 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.

36. Conical Cylindrical

37. TYPES OF PERCOLATION
1. Simple Percolation
2. Modified Percolation
3. Reserved percolation

38. MACERATION VS PERCOLATION
Maceration
• Time consuming and also
extraction is not complete
•Not required skilled
operator
•For certain substances
which are very less soluble
in solvent and requires
only prolonged contact
with solvent.
•Suitable method for less
potent and cheap drugs
Percolation
• short time and more
complete extraction
•Skilled operator is required
•Special attention should be
paid on particle size of
material and throughout
process.
•Suitable method for potent
and costly drugs

39. SOXHALATION

40.  THE SOXHLET EXTRACTOR Continuous
extraction of a component from a solid mixture.
 Boiling solvent vapors rise up through the larger
sidearm. Condensed drops of solvent fall into the
porous cup, dissolving out the desired component
from a solid mixture.
When the smaller side-arm fills to overflowing, it
initiates a siphoning action.

41. The solvent, containing the dissolved component, is
siphoned into the boiler below residual solvent then
drains out of the porous cup, as fresh solvent drops
continue to fall into the porous cup.
. . . and the cycle repeats . . .

42. PURIFICATION
• The purification methods relay mainly on
chromatography and the final product is then
obtained by crystallization.
• Physical techniques are also used for separating and
purifying the plant constituents.
a) Fractional crystallization. b) Fractional liberation.
c) Steam distillation. d) Fractional distillation.
e) Sublimation.

43. FRACTIONAL
CRYSTALLIZATION
• Crystallization is an important method for the
purification of compounds from the mixture.
• Crystallization mostly depends upon the inherent
character of the compound which form the crystals
at the point of super- saturation in solvent in which
it is soluble.

44. METHODS OF
CRYSTALLIZATION
1. Concentration.
2. Slow evaporation.
3. Refrigeration.
• Based on differences in solubility of the components
of a mixture in a particular solvents Valuable.

45. FRACTIONAL LIBERATION
• A mixture of alkaloid salts in aqueous solution, when
treated with aliquots of alkali gives first the weakest
base in the free state followed by base liberation in
ascending order of basicity.
• If the mixture is shaken with organic solvent after each
addition of aliquot of a alkali, a fractional series of
bases shall be obtained.

46. STEAM DISTILLATION:
• Used for the extraction of volatile oils and
hydrocyanic acid from plant material.
FRACTIONAL DISTILLATION:
• Used for the separation of components of volatile oils.
SUBLIMATION:
• We use Sublimation to isolate caffeine from tea and to
• Purified materials present in the crude drug.