History, Definition and Scope

of Pharmacognosy
 pharmacognosy, known initially as materia medica, may
be defined as the study of crude drugs obtained from
plants, animals and mineral kingdom and their
constituents.
 There is a historical misinformation about who created
the term pharmacognosy.
 According to some sources, it was C. A. Seydler, a
medical student at Halle, Germany, in 1815; he wrote his
doctoral thesis titled Analectica Pharmacognostica.
 The physician J. A. Schmidt (Vienna) used that one in his
Lehrbuch der materia medica in 1811, to describe the
study of medicinal plants.
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 The word pharmacognosy is derived from two Latin words
pharmakon, ‘a drug,’ and gignoso, ‘to acquire knowledge of
’. It means ‘knowledge or science of drugs’.
 Pharmacognosy is interdisciplinary, drawing on a broad
spectrum of biological and socio-scientific subjects,
including:-
 Botany, ethnobotany, marine biology, microbiology, herbal
medicine, chemistry, biotechnology, phytochemistry,
pharmacology, pharmaceutics, and clinical pharmacy.
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The American Society of Pharmacognosy defines

pharmacognosy as:
“the study of the physical, chemical, biochemical
and biological properties of drugs, drug
substances or potential drugs or drug substances
of natural origin as well as the search for new
drugs from natural sources "
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Ethno botany: the study of the uses of plants by ethnic groups.

Ethno medicine/Pharmacology: 'the scientific study of

materials used by ethnic and cultural groups as medicines'
Traditional medicine: It is the sum total of all non-mainstream
medical practices, usually excluding so called “western” medicine.
Phytochemistry: It is (from the Greek words phyton = plant and
chemeia = chemistry) deals with the knowledge of natural
products from plant origin exhibiting bioactivity.
Phytotherapy: It is the study of the use of extracts from natural
origin as medicines or health-promoting agents.
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Crude drugs :-are plants or animals, or their parts which after

collection are subjected only to drying or making them into
transverse or longitudinal slices or peeling them in some cases.
Natural Products can be:
1. Entire organism (plant, animal, organism)
2. Part of an organism (a leaf or flower of a plant, an isolated
gland or other organ of an animal)
3. An extract or an exudate of an organism
4. Isolated pure compounds
 The Potential!

 Natural product s have provided the inspiration for most of the

active ingredients in medicines: around 80% of medicinal
products up to 1996 were either directly derived from naturally
occur ring compounds or were inspired by a natural product.
 250,000-500,000 species of higher plants on earth
 < 10% investigated and only for one activity
 Huge potential in plant kingdom
Future: intense screening
• Anticancer – NCI, Antimicrobial, Antiviral,
Antimalarial, Insecticidal, Hypoglycemic, Cardiotonic,
Antiprotozoal and Antifertility – WHO.
Some of the important aspects of the natural
products that led to the modern development of
drugs and pharmaceuticals are as follows:
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1. They provide a number of extremely useful

drugs that are difficult, if not impossible, to
produce commercially by synthetic means
 In an extensive review of new drugs introduced between
1981 and 2002, 28% of the 868 new chemical entities
were natural products or derived from natural products,
with another 24% created around a pharmacophore
from a natural product.
 In addition to launched products, at least 70 natural
product-related compounds were in clinical trials in
2004.
 25% of drugs in use today are derived from natural
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2. Some natural products contain compounds that

demonstrate little or no activity themselves but
which can be modified by chemical or biological
methods to produce potent drugs not easily
obtained by other methods.

• Droscera yam: molecule -> steroids

• Soya: saponins -> steroids
• Baccatin III  Taxol
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• 3. Their utility as prototypes or models for

synthetic drugs possessing physiologic activities
similar to the originals
• Examples:
 Morphine: potent analgesics
 cocaine: local anaesthetics
 Atropine: spasmolytics
 Dicoumarol: anticoagulants
 Salicin: salicylic acid derivatives.
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• 4. Source of toxic molecules/Tools to study new

mechanisms of action
• To study the way the body responds to their
pharmacological use
• Investigating pharmacological mechanisms
• picrotoxin – nerve conduction
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5. Pharmaceutical AIDS of Natural origin

 Pharmacist is responsible for the entire process of manufacturing
the pharmaceutical products, isolation or extraction of active
principles from crude drugs has become a chemical or
biochemical operation.
 A Pharmacists during the manufacturing process of dosage forms
comes across the actual drugs and adjuncts used along with
them.
Drugs
 The word drug has its origin in French Language and has been
derived from the word drouge, which means substance used in
preparation of medicine.
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Pharmaceutical AIDS
 The substances, which are of little or no therapeutic
value, but are essentially used in manufacture or
compounding of various pharmaceuticals are known as
pharmaceutical aids or pharmaceutical necessities.
 They are obtained from various sources such as
animals, vegetables, minerals and synthetic.
Source of pharmaceutical Aids

Animal Vegetable Mineral Synthetic

Bees wax Balsam of Bentonite Acetic acid
tolu
Civet Carnauba Kaolin Boric acid
wax
Honey Peppermint Paraffin Citric acid
Lactose Pectin Talc Calcium
stearate
Spermaceti Starch Chalk Lactic acid
Depending upon the use or application,
pharmaceutical aids from different sources can be
classified as
Class Examples
Colours Turmeric, Saffron, indigo
Disintegrating agents Starch, Carboxyl methyl
cellulose
Diluents Cinnomon water, corn oil,
sesame oil
Emulsifying and suspending Acacia, Agar, Bentonite, gelatin
agents
Filter aids Talk, Kieselguhr
Flavours Cardamom, cinnamon, rose
Hardening agents Bees wax, hard paraffin
Acidulents Tamarind, Lemon juice
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Cocoa butter, Magnesium

Lubricants
stearate

Bees wax, lanolin, paraffin, wool

Ointment bases
fat

Alcohol, glycerine, propylene

Solvents
glycol
HISTORY OF PHARMACOGNOSY

 The history of herbal medicine is as old as human civilization.

 The documents, revealed that plants were used medicinally in China, India,
Egypt andGreece.
 One of the most famous surviving remnants is Papyrus Ebers, a scroll some
60 feet long and a foot wide.
 The text of document is dominated by more than 800 formulae and 700
different drugs.
 knowledge about drugs was acquired through different means
 experience
 migration
 Divine power ???
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 In the early period, primitive man went in search of food and ate
at random, plants or their parts like tubers, fruits, leaves, etc. As
no harmful effects were observed he considered them as edible
materials and used them as food.
 If he observed other effects by their eating they were considered
inedible.
 If it caused diarrhoea it was used as purgative, if vomitting it was
used as memtic and if it was found poisonous and death was
caused, he used it as arrow poison.
 The knowledge was empirical and was obtained by trial and error.
He used drugs as such or as their infusions and decoctions. The
results were passed on from one generation to the other, and
new knowledge was added in the same way
Ancient China
 Chinese pharmacy, according to legend, stems from Shen Nung (about
2700 B.C.), he written the first Pen T-Sao, or Native Herbal, recording
365 drugs.
 These were subdivided as follows:
 120 emperor herbs of high, food grade quality which are non-toxic and
can be taken in large quantities to maintain health over a long period
of time,
 120 minister herbs, some mildly toxic and some not, having stronger
therapeutic action to heal diseases
 125 servant herbs that having specific action to treat disease and
eliminate stagnation. Most of those in the last group, being toxic, are
not intended to be used daily over a prolonged period of weeks and
months.
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 Inscriptions on oracle bones from the Shang Dynasty (1766–1122

B.C.), discovered in Honan Province, have provided a record of
illness, medicines and medical treatment.
 a number of medical treatises on silk banners and bamboo slips
were excavated from the tomb number three at Ma-Huang-Tui in
Changsha, Hunan Province.

These were copied from books some time between the Chin and
Han periods (300 B.C.–A.D. 3)
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• “Shang Hang Lun” written by Chang Chung-Ching (142-220)

• Manual of TCM (Traditional Chinese Medicine)
• Treaties on the treatment of Acute Diseases Caused by Cold
• “Chin Kuei Yao lueh” - Shang Han Lun
• Prescriptions from the Golden Chamber
• Basis for Chinese and Kampo Medicine
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• “ Pen T’sao Jing JI Zhu”- Commentaries on the Herbal Classic.

• Book with 730 herbs
• Six categories Minerals, Grasses and Trees, Insects and
Animals, Fruits and Vegetables, Grains and Named but unused
• In 1578 AD, A book entitled Pen T'sao Kan Mu (Herbal with
commentary) was published.
• The book contained 1892 drugs. 376 described for the first
time with 1160 drawings. It also lists more than 11,000
prescriptions.
Ancient Egypt

 The most complete medical documents existing are the Ebers

Papyrus (1550 B.C.),
 a collection of 800 prescriptions,
 mentioning 700 drugs and the
 Edwin Smith Papyrus (1600 B.C.),
 which contains surgical instructions and formulas for
cosmetics.
 The Kahun Medical Papyrus is the oldest—it comes from 1900
B.C. and deals with the health of women, including birthing
instructions.
INDIA
 Indian s workded to examine and classify the herbs which they
came across, into groups called Guna.
 Charaka made 50 groups of ten herbs.
 Sushrutha arranged 760 herbs in 7 distinct bases on some of their
common properties
 Ayurvedic - Ayur-life ; Veda-study of
 The most celebrated Indian drugs were;
 Sandal wood, Clove, Pepper, Cardamom, Caraway, Ginger,
Benzoin, Cannabis, Castor oil, Sesame oil, Aloes, etc...
Ancient Greece and Rome
Homer: Earliest source of Greek medical knowledge and
descriptions of ancient Greek medical practices.
Two epic poems “Iliad” and “Odyssey” 8th century.
Contained information about treatment of injuries.
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• Hippocrates (460-377 BC)

• “The Father of Medicine”

• Utilized simple natural remedies such as vinegar, honey, herbs
and hydrotherapy.
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Theophrastus (340 AD)

• De Historia Plantarum
• De Causis Plantarum
• Many kinds of plant and how they are used in medicine, how
to grow them and many other observations
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Pliny (60 AD)

 Natural History
 The largest compilation on plants from the Roman period
 Lists more than 1000 plants

Galen (130-200 AD)

 The first pharmacist, Galen, was known to have had a number of
pain relieving materials, including opium in his apothecary.
 Practiced and taught both Pharmacy and Medicine in Rome
 Principles of preparing and compounding of medicines
 Originator of the formula for a cold cream
ISLAMIC CONTRIBUTION

The Arabs added numerous new plants and

medicaments to those already known to the Greeks and
Romans
In their days, pharmacy attained its highest reputation
and became an independent branch of medicine.
It is interesting to note that the first dispensary was
opened in Baghdad, the center of trade in those days
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Ibn Sina (980-1037)

Western world-Avicenna
Kitab ash-shifa – “book of healing”
Canon of Medicine
Physician, Pharmacist, Philosopher and Diplomat
The 18th century, Pharmacognosy

 Johann Adam Schmidt (1759-1809)

 Linnaeus (naming and classifying plants)

 crude drugs were still being used as powders, simple extracts, or

tinctures
WILLIAM WITHERING (1741-1799)
 Discovered the use of Digitalis
 Published “ An Account of The Foxglove and Some of Its Medical
Uses”
Isolated compounds
 Isolation of narcotine from opium (Derosne, 1803)
 Isolated Morphine from opium ( Sertuerner, 1806)
 Strychnine, emitine (1817)
 Brucine, piperine (1819)
 Quinine , colchnine and caffeine (1820)
 Nicotine from tobacco leaves (Posselt and Reimann 1828)
 Atropine (1833)
 Cocaine (Neumann, 1855)
 Pilocarpine ( Gerrard and Hardy, 1875)
 Ouabain ( Hardy and Gallows, 1877)
 Ephedrine ( Nagai, 1887)
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The development of modern pharmacognosy took place later during

the period 1934–1960 by simultaneous application of disciplines like
organic chemistry, biochemistry, biosynthesis, pharmacology and
modern methods and techniques of analytic chemistry, including
paper , thin layer , and gas chromatography and spectrophotometry.

The substances from the plants were isolated, their structures

elucidated and pharmacological active constituents studied. The
development was mainly due to the following four events:-
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1. Isolation of penicillin in 1928 by William Fleming and large-scale

production in 1941 by Florey and Chain.
2. Isolation of resperpine from rauwolfia roots and confirming its
hypotensive and tranquilizing properties.
3. Isolation of vinca alkaloids, especially vincristine and
vinblasting. Vincristine was found useful in the treatment of
leukaemia. These alkaloids also have anticancer properties.
4. Steroid hormones like progesterone were isolated by partial
synthesis from diosgenin and other steroid saponins by Marker’s
method. Cortisone and hydrocortisone are obtained from
progesterone by chemical and microbial reaction.
SCOPE OF PHARMACOGNOSY

Studying crude drugs

Identifying biological sources of drugs and assessing the efficacy and
safety of herbal drugs or their constituents as therapeutic agents using
scientific methods
Plants, Microorganisms (bacteria, fungus), Marine organisms &
Animal products = (Biomass)
Securing regular supply of natural products
cultivation
increasing yield
Semi-synthesis and synthesis? Why???
~ 100 species/day is lost i.e. loss of potential new medicines
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 Scope for doctoral graduates in pharmacognosy is going to increase

in the coming years. The pharmacognosy's would serve in various
aspects as follows:
Academics: Teaching in colleges, universities, museums and
botanical gardens.
Private industry: Pharmaceutical companies, consumer products
testing laboratories and private commercial testing laboratories, the
herbal product industries, the cosmetic and perfume industries, etc.
Government: Placement in federal agencies, such as the Drug
Enforcement Agency, the Food and Drug Administration, the U.S.
 FUTURE OF PHARMACOGNOSY
 Medicinal plants are of great value in the field of treatment and
cure of disease.
 It has now been universally accepted fact that the plant drugs
and remedies are far safer than that of synthetic medicines for
curing the complex diseases like cancer and AIDS.
 The modern developments in the instrumental techniques of
analysis and chromatographical methodologies have added
numerous complex and rare natural products to the armoury of
phytomedicine.
 Example
 artemissinin as antimalarial,
 taxol as anticancer,
 forskolin as antihypertensive,
 rutin as vitamin P and capillary permeability
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 In the Western world, as the people are becoming aware of the

potency and side effects of synthetic drugs, there is an
increasing interest in the plant-based remedies with a basic
approach towards the nature.
 Terrestrial and marine, and it largely depends upon the
forthcoming generations of pharmacognosists and
phytochemists to explore the wonder drug molecules from this
unexploited wealth.
 The future developments of pharmacognosy as well as herbal
drug industry would be largely dependent upon the reliable
methodologies for identification of marker compounds of the
extracts and also upon the standardization and quality control
of
 Production of Natural Products

1. Collection (wild)
2. Cultivation (commercial)
3. Fermentation
• Recombinant DNA technology or Genetically engineered
drugs
4. Cell-culture techniques
5. Microbial transformation
6. Biologics (prepared from the blood of animals)
PHARMACOGNOSTICAL SCHEME
To describe drugs in a systematic manner is known as
pharmacognostical scheme, which includes the following
headings:
1. Biological Source
This includes the biological names of plants or animals yielding
the drug and family to which it belongs. Botanical name includes
genus and species.
According to the biennial theory, the botanical name of any plant
or animal isalways written in italic form, and the first letter of a
genus always appears in a capital later.
2. Geographical Source
It includes the areas of cultivation, collection and route of transport
of a drug
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3. Cultivation, Collection and Preparation

These are important to mention as these are responsible for
quality of a drug.
4. Morphological Characters
In case of organized drugs, the length, breadth, thickness, surface,
colour, odour, taste, shape, etc. are covered under the heading
morphological characters, whereas organoleptic properties (colour,
odour, taste and surface) should be mentioned, if the drug is
unorganized.
5. Microscopical Characters
This is one of the important aspects of pharmacognosy as it helps
in establishing the correct identity of a drug. Under this heading all
the detailed microscopical characters of a drug is described
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6. Chemical Constituents
 The most important aspect which determines the intrinsic value of a drug to which
it is used is generally described under this heading. It includes the chemical
constituents present in the drug. These kinds of drugs are physiologically active.
7. Uses
 It includes the pharmaceutical, pharmacological and biological activity of drugs or
the diseases in which it is effective.
8. Substituents
 The drug which is used during non-availability of original drug is known as
substituent. It has the same type of physiological active constituents; however,
the percentage quantity of the drug available may be different.
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9. Adulterants
 Most of the times the adulterants are completely devoid of
physiologically active constituents, which leads in the
deterioration of the quality. For example, mixing of buffalo milk
with goat milk is substitution, whereas mixing of water in the
milk is adulteration. In the first case, goat milk is substitute and
in the second case water is adulterant.
10. Chemical Tests
 The knowledge of chemical tests becomes more important in
case of unorganized drugs whose morphology is not well defined
Botany: Morphology and Systematics

 Arrangements of plants into groups and subgroups are commonly

spoken as classification, known as Taxonomy or Systematic
botany.
 The Taxonomy word is derived from two Greek words ‘Taxis’
meaning an arrangement and ‘nomos’ meaning laws. Therefore,
the systemization of our knowledge about plants in an orderly
manner becomes subject matter of systematic botany.
 The aim and objective of taxonomy is to discover the similarities
and differences in the plants, indicating their closure relationship
with their descents from common ancestry. It is a scientific way
of naming, describing and arranging the plants in an orderly
manner.
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CLASS
 Angiospermae (Angiosperms) : Plants which produce flowers
 Gymnospermae (Gymnosperms) : Plants which don't produce flowers
SUBCLASS
 Dicotyledonae (Dicotyledons, Dicots) : Plants with two seed leaves
 Monocotyledonae (Monocotyledons, Monocots) : Plants with one seed leaf
SUPERORDER
 A group of related Plant Families, classified in the order in which they are
thought to have developed their differences from a common ancestor.
 The names of the Superorders end in -idae
ORDER
 Each Superorder is further divided into several Orders. The names of the
Orders end in -ales
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• FAMILY
 Each Order is divided into Families. These are plants with many
botanical features in common, and is the highest classification normally
used. At this level, the similarity between plants is often easily
recognisable by the layman.
 Modern botanical classification assigns a type plant to each Family,
which has the particular characteristics which separate this group of
plants from others, and names the Family after this plant.
 The number of Plant Families varies according to the botanist whose
classification you follow. Some botanists recognise only 150 or so
families, preferring to classify other similar plants as sub-families, while
others recognise nearly 500 plant families. A widely-accepted system is
that devised by Cronquist in 1968, which is only slightly revised today.
 The names of the Families end in -aceae
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GENUS
The plants in a Genus are often easily recognisable as
belonging to the same group.
The name of the Genus should be written with a capital letter.

SPECIES
This is the level that defines an individual plant. Often,
 The name will describe some aspect of the plant - the colour
of the flowers, size or shape of the leaves, or it may be named
after the place where it was found.
The name of the species should be written after the Genus
name, in small letters, with no capital letter.
Example

Division Angiospermae
Class Dicotyledoneae
Family Labiatae (Lamiaceae)
Genus Mentha
Species Mentha piperita Linnaeus (peppermint)
Varieties Mentha piperita var. officinalis Sole
(White Peppermint);
Mentha piperita var. vulgaris Sole (Black
Peppermint)
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The Binomial System

 is due to Swedish biologist Linnaus
 in this system the first name, which is always spelt with Capital
letter, denotes the genus
 the second name denotes the species.
• Example : Mentha piperita
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 The classification of plants may be based upon variety of

characters possessed by them.

 Features like specific morphological characters, environmental

conditions, geographical distribution, colours of flowers and types
of adaptations or reproductive characteristics can be used as a
base for taxonomical character
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1- Some striking characteristics of the plant:

a- Conium maculatum (maculate = spotted)
• stem with reddish, spotted patches
b- Glycyrrhiza glabra (glabrous = smooth)
• the fruit of this species which is a smooth pod
c- Hyoscyamus muticus (muticus = short).
• the plant being short
d- Atropa belladonna (bella = beautiful, donna = lady)
• the juice of the berry placed in the eyes causes dilatation of
the pupils, thus giving a striking appearance
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2- A characteristic colour:
a- Piper nigrum (= black)
b- Veratrum viride (= green)
c- Citrus aurantium (= golden yellow)
d- Digitalis purpurea (= purple)
e- Digitalis lutea (= yellow)
3- An aromatic plant or certain aroma:
a- Myritaceae fragrans (having a fragrant, nice aroma)
b- Caryophyllus aromaticus (refers to the aroma)
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4- A geographical source or history of a drug:

a- Cannabis indica (growing in India)
b- Tamarinds indica (India)
5- A Pharmaceutical activity or an active constituents:
a- Papaver somniferum (sleep inducing)
b- Strychnos nux vomica (from two latin words, nut causing
vomiting)
c- Ipomoea purga (laxative)
6- A general meaning or a special indication
a- Allium sativum (= cultivated)
b- Triticum vulgaire (= wild)
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The generic name may also allude to certain characters of the

plant:
• Atropa, from Atrops, meaning flexile
• the name of the Greek fate who cuts the thread of life,
alluding to the poisonous characters of the drugs
• Glycyrrhiza is from glucose= sweet, riza = root
Scientific name is written in italics or is underlined in texts
2.2. Morphology of Higher Plants

1. Flower
 It is the essential reproductive organ of a plant
 For an inexperienced observer, two characteristics of a flower are
particularly noteworthy: the size and the color
 Although the flowers are of great botanical importance, they are
only a minor source of drugs used in phytotherapy or pharmacy
e.g. chamomile, Matricaria recutita L. (Asteraceae )
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• Flower consists of 4 different circles (whorls)

• A flower is built upon stem or pedicel with enlarged end known as
thalamus or receptacle.
• Calyx: it is outer most whorl of flower and it is generally in green
colour. The individual member of calyx is called as sepal.
• Corolla: it is either white or bright coloured. Each member of corolla is
known as petal. The number of petals varies with the type of flower.
• Androecium: It constitutes the male part. The individual component is
called as stamen and each stamen consist of filaments, anther and
connective.
• Gynoecium: it constitute of female part. Each component is called as
carpel or pistil and is made of stigma, style and ovary.
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2. Fruit and seed

 The lower plants, such as algae, mosses and ferns, do not
produce seeds
 Drugs from the fruit thus have to be derived from an angiosperm
species
Fruit
Caraway, Carum carvi L. (Umbelliferae)
Seed
(white) mustard, Sinapis alba L. (Brassicaceae)
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 The phanerogams are said to be matured, when they reach the
flowering stage. The ovules of flowers, after fertilization, get
converted in to seeds, where as the ovary wall develops further to
form the protecting cover over seeds, which is known as fruit.
• In botany, this particular coating is also called pericarp.
• Pericarp consists 3 different layers
• Epicarp : it is outermost coating of the pericarp and may be thin,
thick or woody.
• Mesocarp: a layer between epicarp and endocarp, may be pulpy or
made up of spongy paranchymatous tissue.
• Endocarp: the innermost layer of the pericarp, may be thin, thick
or woody.
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Seed
 The seed is a fertilized ovule.
 It represents a condensed form of life and it is a characteristic of
phanerogams.
 Parenchymatous body of the ovule known as nucellus, contains embryo-sac
surrounded by integuments (coating). In embryo-sac itself fertilization
takes place giving rise to embryo.
 The seed is having 3 parts known as embryo, endosperm and seed coat.
Embryo is the nutritive tissue nourishing the embryo.
• Classification of seed:
1. Endospermic or albiminous seeds: A part of the endosperm remains until
the germination of seed and is partly absorbed by embryo. It shows distinct
presence of endosperm.
E.g: Colchicum, Isapgol, Nux-vomica.
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2. Non- Endospermic or Exalbuminous seeds: during development of seed, the

endosperm is fully absorbed by embryo and endosperm is represented in the
natural seed.
E.g: Sunflower, Tamarind, Cotton, Soyabean
3. Perispermic seed: The nucleus develops t such an extent that it forms a big
storage tissue and seeds are found too contain embryo, endosperm, perisperm
and seed coat.
E.g: Pepper, Cardmom, Nutmeg
Seed Characters:
Hilum: this is the point of attachment of seed to stalk.
Micropyle: it is the minute opening of the tubular structure, wherefrom water
is provided for the germination of seed.
Raphe: it is logitudinal marking of adherent stalk of anatropousovule.
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3. Leaves
The function of the leaves, as collectors of the sun’s energy and its
assimilation, results in their typical general anatomy with a petiole
(stem) and a lamina (blade)
A key characteristic of a species is the way in which the leaves are
arranged on the stem, they may be:
1. Alternate
2. Distichous
3. Opposite
4. Decussate
5. Whorled
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4. Bark
 The secondary external tissues lying outside the cambium in stem or
root of dicotyledonous plants, are known as the bark.
 Botanically, bark is also known as periderm. It consists of 3 layers
• Cork ( Phellem)
• Cork- Cambium (Phellogen)
• Secondary cortex ( Phelloderm)

 Commercially, bark consists of all the tisues outside the cambium.

 A young bark includes epiderm, cortex, pericycle and phloem.
Shape of the bark: Shape depend on the type of incision made and
the text of any subsequent shrinking of tissues.
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When the bark is removed from the large trees and dried under
pressure, the flats are produced e.g: Quillaia and Arjuna barks.
When the bark is removed from the small branches due to shrinkage of
the soft tissues, it tends to curve forming concavity on the iinner side
yielding curved pieces e.g: Wild cherry and Cassia bark.
If the concavity is on the outer side of the bark, it is descried as
recurved. E.g: Kurchi bark.
When the shrinkage of the tissues is to a greater extent and it
formsdeep through or channel, it is called a channelled bark e.g:
Ashoka and Cinchona ledgeriana and cassia
In some cases, one edge of a bark covers the other to form quill e.g.:
Cascara and cinnamon.
If both the edges of the bark roll independently forming quill, it
described double quill e.g: Java cinnamon.
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Methods of collecting barks

Barks are collected in a season when they contain maximum concentration of
constituents.
Cinnamon is collected in rainy season and wild cherry bark collected in
autumn.
Filling method: this is very old method of collecting barks. The tree is cut base
and bark is peeled out.
Uprooting method: in this case, roots of the plant are dug out of the soil and
bark stripped off from root and branches. This method is applied for collection
of root bark of cinchona in Java.
Coppicing method: in this method, the plant I allowed to grow for a definite
period and then it is cut off at specific distance from soil. The stumps,which
remain in ground are allowed to send shoots, which develop further
independently yielding aerial parts.
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5. Rhizome and root drugs

• Underground organs of only a few species have yielded
pharmaceutically important drugs e.g.
1. Sarsaparilla, Smilax regelii (famiy : Smilacaceae)
2. Korean ginseng, Panax ginseng (Family: Araliaceae)
6. The bulbs and exudatesa
3. Garlic, Allium sativum L. (Family: Liliaceae)
4. Aloe vera L. (Family: Asphodelaceae)
CRUDE DRUG
Introduction

 Crude drugs can be regarded as the substances either used

directly or indirectly as a drug which have not been changed or
modified in its chemical composition.
 Any naturally occurring, unrefined substance derived from
organic or inorganic sources such as plant, animal, bacteria,
organs or whole organisms intended for use in the diagnosis,
cure, mitigation, treatment, or prevention of disease in man or
other animals
 The crude drugs of natural origin can be divided into two main
categories as organized crude drugs and unorganized crude
drugs.
Organized Drugs
• Organized drugs consist of the cellular organization in the form of
anatomical features. These are mostly the crude drugs from plant sources.
• Almost all of the morphological plant parts or the entire plant itself can be
called as an organized drugs.
• To mention few of them, like, Cinchona bark, Sandalwood, Quassia wood,
Senna, Digitalis leaves, Nux vomica seeds, Rauwolfia roots.
• Microscopical and anatomical studies are preeminent for such crude
drugs.
 Unorganized Drugs
 The unorganized drugs do not have the morphological or anatomical organization as
such.
 These are the products which come directly in the market but their ultimate source
remains the plants, animals or minerals.
 Microscopical studies are not required for such crude drugs.
 These includes products like plant exudates as gums, oleogums, oleo gum resins, plant
lattices like that of opium, aloetic juices like aloes or dried extracts of black and pale
catechu, agar, alginic acid, essential oils, fixed oils, fats and waxes obtained from
vegetable or animal sources, etc.,
Some Terminology
 Botanical origin or botanical source crud drug: it is from plant
 Zoological origin or source crud drug : it is from animal
 Indigenous : Plants growing in their native countries
 Naturalized : when they grow in a foreign land or in locality other than
their native home
CLASSIFICATION OF CRUDE DRUGS
• The most important natural sources of drugs are higher plant, microbes and
animals and marine organisms.
• A method of classification should be:
 simple,
 easy to use, and
 free from confusion and ambiguities.
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1. Alphabetical classification
2. Taxonomical classification
3. Morphological classification
4. Pharmacological classification
5. Chemical classification
6. Chemotaxonomically classification
7. Serotaxonomical classification
 1. Alphabetical Classification

• Alphabetical classification is the simplest way of classification of any

disconnected items.
• Crude drugs are arranged in alphabetical order of their Latin and English
names (common names) or sometimes local language names (vernacular
names).
• This classification is adopted by following books
British Pharmacopoeia (English)
British pharmaceutical codex (English)
United states of Pharmacopoeia (English)
Pharmacopoeia International (Latin)
Indian Pharmacopoeia (English)
British Herbal Pharmacopoeia (English)
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Merits
 It is easy and quick to use.
 There is no repetition of entries and is devoid of confusion.
 In this system location, tracing and addition of drug entries is easy.
Demerits
There is no relationship between previous and successive drug entries
Does not help in distinguishing the drugs from plants, animals or mineral sources
Does not indicate whether they are organised or unorganised drugs.
 2. Taxonomical Classification
• It is a type of biological classification & restricted mainly to crude
drugs from plant source.
• In this classification the crude drugs are classified according to
kingdom, subkingdom, division, class, order, family, genus and
species as follows.
Merits
Taxonomical classification is helpful for studying evolutionary
developments.
Precise & ordered arrangement (no ambiguity)
Demerits
This system also does not correlate in between the chemical
constituents and biological activity of the drug.
Failure to recognize the organised and unorganised nature of
3. Morphological Classification
 In this system, the drugs are arranged according to the morphological or external
characters of the plant parts or animal parts.
 The drugs obtained from the direct parts of the plants and containing cellular
tissues are called as organized drugs, e.g. rhizomes, barks, leaves, fruits, entire
plants, hairs and fibres.
 The drugs which are prepared from plants by some intermediate physical
processes such as incision, drying or extraction with a solvent and not containing
any cellular plant tissues are called unorganized drugs. Aloe juice, opium latex,
agar, gambir, gelatin, tragacanth, benzoin, honey, beeswax, lemon grass oil etc.
 Count..
Merits
• Morphological classification is more helpful to identify and detect adulteration. This
system of classification is more convenient for practical study especially when the
chemical nature of the drug is not clearly understood
Demerits
• The main drawback of morphological classification is that there is no correlation of
chemical constituents with the therapeutic actions.
• Repetition of drugs or plants occurs
4. Pharmacological Classification
• Grouping of drug according to their pharmacological action or of most important
constituent or their therapeutic use is termed as pharmacological or therapeutic
classification of drug.
• This classification is more relevant and is mostly a followed method.
Merits
This system of classification can be used for suggesting substitutes of drugs, if
they are not available at a particular place or point of time.
Demerits
Drugs having different action on the body get classified separately in more than
one group that causes ambiguity and confusion. Cinchona is antimalarial drug
because of presence of quinine but can be put under the group of drug affecting
heart because of antiarrhythmic action of quinidine
1
Example
Sl.No. Pharmacological category
Drug acting on G.I.T.
Example

Bitter Cinchona, Quassia, Gentian

Antiamoebic Fennel, Cardamom, Mentha
Laxative Agar, Isabgol, Banana
Purgative Senna, Castor oil
Cathartic Senna

2 Drug acting on Cardiovascular system

Cardio tonic Digitalis
Vasoconstrictor Ergot
Antihypertensive Rauwolfia

3 Drug acting on Central nervous system

Central analgesic Opium (morphine)
 5. Chemical Classification
• Depending upon the active constituents, the crude drugs are classified. The plants
contain various constituents in them like alkaloids, glycosides, tannins, carbohydrates,
saponins, etc.es
Alkaloids: Aconite, cinchona
Glycosides : Digitalis, senna
Lipids : Castor oil, peanut oil
Volatile oils : Peppermint, clove
Tannins: Myrobalan, kino
Vitamins: Yeast, cod liver oil
Resins : Benzoin, guggul
Carbohydrates and derived products: Agar, honey
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Merits
It is a popular approach for phytochemical studies.
Demerits
Ambiguities arise when particular drugs possess a number of compounds
belonging to different groups of compounds.
 6. Chemotaxonomically
Classification
 This system of classification relies on the chemical similarity of a taxon
 It is based on the existence of relationship between constituents in various plants.
 There are certain types of chemical constituents that characterize certain classes of
plants.
For example:-
tropane alkaloids generally occur among the members of Solanaceae, thereby,
serving as a chemotaxonomic marker.
berberine alkaloid in Berberis and Argemone
Rutin in Rutaceae members
 It is the latest system of classification that gives more scope for understanding the
relationship between chemical constituents, their biosynthesis and their possible
action.
 7. Serotaxonomical Classification
 The serotaxonomy can be explained as the study about the application or the utility
of serology in solving the taxonomical problems.
 Serology can be defined as the study of the antigen–antibody reaction.
 Antigens are those substances which can stimulate the formation of the antibody.
 Antibodies are highly specific protein molecule produced by plasma cells in the
immune system.
 It expresses the similarities and the dissimilarities among different taxa, and these
data are helpful in taxonomy.
 It determines the degree of similarity between species, genera, family.
 Evaluation of crude drugs

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In general, quality control is based on three important

pharmacopoeia definitions:
1. Identity:
Is the herb the one it should be?
2. Purity:
 Are there contaminants, e.g., in the form of other herbs which
should not be there?
3. Content or assay:
 Is the content of active constituents within the defined limits?
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Evaluation of crude drugs

Evaluation deals with:

 the correct identification of the plant
 determination of the quality & purity
 detection of nature of adulteration
Reasons for crude drug evaluation
 biochemical variation in the drug
 deterioration due to treatment & storage
 substitution and adulteration
Identification of the plant
 comparison with authentic or genuine sample
 comparing the published description of the drug with
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• Methods currently employed in evaluating herbs are
organoleptic, microscopic, physical, chemical, and biological
parameters.
1. Organoleptic
 Evaluation by means of the organs of sense and includes the
macroscopic appearance of the drug
Shape and size.
Colour and external markings
Fracture and internal colour
Odour and taste
Special features like touch, texture and sound.
 Organoleptic analysis represents the simplest, yet the most
human form of analysis.
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2. Microscopic evaluation

This method is used for identification of drugs on cellular level.

It is used to determine structure of organized drugs by their
histological characters. It includes examination of whole, certain
parts or powdered crude drugs.
The leaf constants like:
stomatal number
stomatal index
palisade ratio
vein islet
vein termination number

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Stomatal Number
• It is the average number of stomata present per square mm of
the epidermis.
• Stomatal number is relatively a constant for particular species of
same age and hence, it is taken into consideration as a
diagnostic character for identification of a leaf drug. The
adulteration
Species can also detected by stomatal
Stomatal number.
Number
Datura Stamonium 087 ( Upper Epidermis)
Datura innoxia 141 ( Upper Epidermis)
Hyoscyamus niger 125 ( Upper Epidermis)

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 Stomatal Index:
• It is the percentage which the number of stomata form to the total
number of epidermal cells, each stomata being counted as one cell.
I = S X 100
(E+S)
Species Stomatal Index
(Lower Surfaces)
Atropa belladonna 20.2 to 23.0
• Where I = stomatal Index Atropa acuminata 16.2 to 18.3
• S = Number of stoma per unitIndian
area senna 17.0 to 20.0
• E = Epidermal cells in the same area
• The number varies with age of leaf due to changes in climatic
conditions

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 Vein islet number:

• It is the number of vein islet per. Sq mm of leaf surface.
• It is a constant for a given species of the plant
• It usually does not alter with the age of plant and it is dependent
on the size of the leaf
Species Vein islet number
Digitalis purpurea 02 – 5.5
Digitalis thapsi 8.5 – 16
Cassia angustifolia 19 – 23
Cassia acutifolia 25 - 30

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Palisade ratio:
• It is the average number of palisade cells, beneath one epidermal
cells, using four continuous epidermal cells for the count.
• Since the palisade cell in the mesophyll of the leaves bear a
definite relation to the epidermal cell.

Species Palisade ratio

Atropa belladonna 06 - 10
Datura Stamonium 04 - 07
Digitalis purpurea 3.7 – 4.2

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3. CHEMICAL EVALUATION

 The chemical evaluation includes qualitative chemical tests,

quantitative chemical tests, chemical assays, and instrumental
analysis.
 The isolation, purification, and identification of active constituents
are chemical methods of evaluation.
 Examples of identification of constituents are:
copper acetate used in the detection of colophony present as an
adulterant for resins, balsams, and waxes;
Holphen’s test for cottonseed oil and
Baudouin’s test for sesame oil in olive oil;
the test with acetic and nitric acids for Gurjun balsam in copaiba;
Van Urk’s reagent for ergot
Vitali’s morins reaction for tropane alkaloids; iodine for starch etc.
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 Quantitative chemical tests such as acid value (resins,

balsams), saponification value (balsams), ester value (balsams,
volatile oils), acetyl value (volatile oils), etc.
 Chemical assays include assays for alkaloid, resin, volatile oil,
glycoside, vitamins, or other constituent.
 Instrumental analyses are used to analyse the chemical
groups of phytoconstituents using chromatographic and
spectroscopic methods.

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4. PHYSICAL EVALUATION

 In crude plant evaluation, physical methods are often used to

determine the solubility, specific gravity, optical rotation,
viscosity, refractive index, melting point, water content, degree
of fibre elasticity, and other physical characteristics of the herb
material.
 Specific gravity is used occasionally. e.g. drugs that sink or not
sink in water.
 Elasticity may also be used
 Uv interaction of certain drugs is important quality.
 Some alkaloids give distinct colors with uv –light.
 Aconite-----light blue, Berberine ----yellow, Emetine-------orange.
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Solubility
 Drugs specific behaviours towards solvents are taken into consideration. This is
useful for the examination of many oils, oleoresins.
Few examples: - are the solubility of colophony in light petroleum, the solubility
of balsam of Peru in solution of chloral hydrate, the solubility of castor oil in half
its volume of light petroleum.
Optical Rotation
 Anisotropic crystalline solids and samples containing an excess of one
enantiomer of a chiral molecule can rotate the orientation of plane-polarized
light. Such substances are said to be optically active, and this property is known
as optical rotation.
 The enantiomer that rotates light to the right, or clockwise, is called the
dextrorotatory (d) or (+) enantiomer, and the enantiomer that rotates light to
the left, or counterclockwise, is called the levorotatory (l) or (-) enantiomer.

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Specific Gravity
 It is also known as relative density.
 The ratio of the mass of a solid or liquid to the mass of an equal
volume of distilled water at 4°C (39°F) or of a gas to an equal volume
of air or hydrogen under prescribed conditions of temperature and
pressure.
 Some examples of specific gravity of drugs are cottonseed oil 0.88–
0.93, coconut oil 0.925, castor oil 0.95, etc.
Viscosity
 Viscosity is the resistance of a fluid to flow.
 Viscosity of a liquid is constant at a given temperature and is an index
of its composition.
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Melting Point
 The melting point of a solid is the temperature at which it changes state
from solid to liquid. Plant constituents have very sharp and constant
melting points.
 for example, beeswax 62–65°C, wool fat 34–44°C, agar melts at 85°C, etc .
Moisture Content
 An inevitable (unavoidable) component of crude drugs is moisture.
eliminated as far as practicable
 The moisture content of a plant material is important from a stability
perspective.
 Responsible for decomposition of crude drugs either producing chemical
change or microbial growth.
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The moisture content affects the following parameters:

Microbial growth, which may be bacterial or fungal growth and
is deleterious to the drug.
Enzymatic activity inside the plant cells may be a threat to the
stability of the compounds.
On drying, the bulk of the material also gets reduced, which
helps in the storage of the plant material.
After drying, further comminution and size reduction becomes
easier for the drug.
 The moisture content is determined by heating a drug at 105°C
in an oven to a constant weight.

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Ash Values
 The determination of ash is useful for detecting low-grade
products, exhausted drugs, and excess of sandy or earthy matter.
 an ash determination furnishes a basis for judging the identity and
cleanliness of a drug.
 The ash content of a crude drug is generally taken to be the
residue remaining after incineration.
 This includes:
 “physiological ash”, which is derived from the plant tissue itself
 “non-physiological” ash, which is the residue of the extraneous
matter (e.g. sand and soil) adhering to the plant surface.

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 Two major types of ashing are used

dry ashing, primarily for proximate composition and for
some types of specific mineral analyses
wet ashing (oxidation), as a preparation for the analysis of
certain minerals
 The ash value of crude drugs is determined using the dry ashing
method
finely powdered drug is first heated to around 675°C
the organic matter is oxidized to carbon dioxide and
removed
 It is expected to yield a carbon-free ash, which is
identified by a dull grayish, white, pinkish, or red
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Acid-Insoluble Ash
 Acid-insoluble ash is an indication of the portion of the ash that is
insoluble in dilute hydrochloric acid
 It indicates mainly the silica and sand-like substances present in
the ash
Water-Soluble Ash
 Water-soluble ash is a determinant of whether the substance was
previously extracted
 detecting exhausted drugs

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 The dry ashing technique  The wet ashing technique

 Safer technique  involves lower temperature

 It prevents loss of volatile

may also be considered
simpler materials, such as As, Se, Hg, K,
 Most
P, & S from the crude drug.
widely used for the  useful for the determination of
determination of the ash value heavy metals by atomic
of crude vegetable drugs. absorption spectroscopy or flame
 Limitation: photometry later.
 It causes a loss of volatile  Limitation
materials due to heating at  it needs constant operator

high temperatures attention

 Equipment set up and handling  expensive setups for proper

management of the fumes,

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Extractive values:
 The total soluble constituent of the drug in any solvent or mixture
of solvents may called as its extractive value or percentage of
extractive.
 The extractions of any herbal drug with a particular solvent yield
a solution containing different phytoconstituents
 The compositions of these phytoconstituents depend on
 Nature of the drug
 Solvent used
 They also give an indication of whether the crude drug is
exhausted or not.
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Water-soluble extractive is used for crude drugs containing water-

soluble constituents like glycosides, tannins, mucilage, etc.;
alcohol-soluble extractive is used for crude drugs containing
tannins, glycosides, resins, etc.; and
Alcohol insoluble extractives: These extractive values are
applicable to some resinous drugs
ether-soluble extractives are used for drugs containing volatile
constituents and fats.

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Foreign matter
 Foreign matter is material consisting of any or all of the
following:
 parts of the herbal material or materials other than those named with
the limits specified for the herbal material concerned
 any organism, part or product of an organism, other than that named
in the specification and description of the herbal material concerned
 mineral admixtures not adhering to the herbal materials, such as soil,
stones, sand and dust
 Herbal materials should be entirely free from visible signs
of contamination

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Biological (Bioassay) Evaluation

 When the estimation of potency of crude drug or its preparation is

done by means of its effect on living organism like bacteria, fungal
growth or animal tissues or entire animal, it known as bioassay.
 Bioassay is the measure of sample being tested capable of
producing the biological effect as that of standard preparation.
 Such an activity is represented in units known as international
units (I.U)
 It includes the quantitative assay of the drugs using biological
models of intact animals, animal preparations, isolated living
tissues or microorganisms
 it is less precise, time consuming & more expensive to conduct

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Generally used if:

 The chemical identity of the active principle in not fully elucidated
 If no adequate chemical assay has been derived for the active
principle as incase of insulin
 If the chemical assay is not a valid indication of biological activity
 If the drug is composed of complex mixture and activity. E.g.
Digitalis,
 If purification of the crude drug is not possible E.g. Separation of
vit. D from irradiated oils
 To measures the actual biological activity of a given sample

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In-vitro Bioassays In-vivo Bioassays

are rapid more selective
less selective, but expensive
diagnostic mostly time consuming
less expensive animal model
suitable for minute amounts require large amounts of
of materials material
suitable for screening large hardly could guide the
number of samples in drug fractionation of extracts or
discovery programs mixture of compounds
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Summary

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ADULTRATION

 Adultration is the substitution of the original crude drug partially

or fully with other substances which is either free from or inferior
in therapeutic and chemical properties, addition of low grade or
spoiled drugs or entirely different drug similar to that of original
drug substituted with an intention of enhancement of profits.
 Its is the debasement of genuine materials
 It is deliberate or accidental substitution of a herbal drug
 Deliberate substitution/adulteration is done when
There is scarcity of crude drugs or
Cost of the drug is high even though there is no scarcity

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Adulteration may takes place by two ways:

1. Direct or intentional adulteration
2. Indirect or unintentional adulteration
1. Direct or intentional adulteration
It is done intentionally which usually includes practices in which an
herbal drug is substituted partially or fully with other inferior products.
Some are
1. With artificially manufactured materials
2. With inferior quality materials
3. With exhausted material
4. With foreign matter
5. With harmful / Fictitious substances
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2. Indirect or unintentional adulteration

 Unintentional or undeliberately adulteration which sometimes occurs

without bad intention of the manufacturer or supplier.
1. Faulty collection
2. Imperfect preparation
3. Incorrect storage
4. Gross substitution with plant material
5. Substitution with exhausted drugs

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Categories of adulteration
1. INFERIORITY:
2. SPOILAGE:
3. DETERIORATION:
4. ADMIXTURE:
5. SOPHISTICATION:
6. SUBSTITUTION:
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1. INFERIORITY
 It is the condition in which substandard drug is produced
naturally, irrespective of the cause
 e.g. Collection time of herbal drug: selection of a herbal
species that contain same active constituent but lesser in
amount.
 Due to morphological resemblance to the authentic drugs,
different inferior commercial varieties are used as adulterant
 which may or may not have any chemical or therapeutic
potential as that of original natural drug

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2. SPOILAGE
 It refers to a process in which the quality has been so impaired and
destroyed by action of microorganisms
 fungi and
 bacteria as to render the article unfit for human consumption.
3. DETERIORATION
 It refers to any impairment in the quality due to some physical processes
e.g.
 aging,
 moisture,
 heat,
 resulting in destruction of its valuable constituents due to insects or
microorganisms
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4. ADMIXTURE
 It refers to addition of one article to another either
 accidently or
 due to ignorance or carelessness
 e.g. Root based herbal drug with adhering soil.
 There is a limit for admixture and presence of admixture in
quantities higher than establish limits results in adulteration.

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5. Sophistication
It means addition of spurious or inferior material to
herbal drug with an intent to defraud
 e.g. Addition of wheat flour to powdered ginger, with
enough capsicum to restore or enhance the
pungency and curcuma to maintain the color.

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6. SUBSTITUTION
It is a process in which such adulterants are used that
resemble actual drug
 in morphology,
 chemical constituents and
 in some cases in therapeutic efficacy but substandard in
nature and hence cheaper in cost
e.g. capsicum minimum is substituted with capsicum annuum.
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Official and unofficial drugs

Drugs are either official or unofficial. An official drug is one

which is listed and described in a book recognized by the
government as the legal authority for standards
"Pharmacopoeia"

Unofficial drug are substances that have been recognized in

either official pharmacopeias or National Formularry but are
not presently found in the current issues.

Nonofficial drugs are substances that have never been

appeared in either books.
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In the monograph of a crude drug the following information are

generally covered:
 English, Arabic, Latin & French names
 Definition
 Description special condition for collection
 Preparation for the market, identity tests, tests for adulterant
 Method of assay,
 Special storage requirements
 The usual dose and range of dosage if the drug is
administered internally
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 Scheme for Pharmacognostic Studies of a Crude Drug

 Official title, synonyms or vernacular names, if any.

 Biological source and family.
 Geographical source or habitat.
 History and introduction of crude drug.
 Cultivation collection, processing for market and commerce in crude drugs.
 Morphological or macroscopical character.
 Microscopic or histological studies.
 Chemical constituents and qualitative chemical tests
 Pharmacological actions, therapeutic and other Pharmaceutical uses and
Pharmaceutical preparation or formulations.
 Commercial varieties, substitutes and adulterants
 Storage and preservation of crude drugs
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4. S

4. Steps in the Scientific Analysis of Drugs from

Natural Resources Resources
1. Selection and collection of plant material
 Accidental experience
 Doctrine of signatures
 Random screening
 Traditional use
 Littérature Information Sélection Technique (L.I.S.T.)
 Selection based on chemotaxonomy

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2.Taxonomic identification of the plant

• Pressing

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3.Literature survey
 to get update on current knowledge about the plant
 helps to avoid repetition
 helps to design methods of extraction …..
 to check consistency of folkloric use

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4. Design of appropriate extraction method

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5. Checking extracts/ fractions for pharmacological

activity
• In-vitro and In-vivo

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6. Phytochemical screening
• Chemical tests and Chromatography

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7. Structure Determination

• NMR
• MS
• UV-vis
• IR

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Approaches to Screening Process

1. Phytochemical Approach
 Requires firstly the isolation of a pure compound from the plant, and
then to determine its bioactivity (if any) by applying the classic
pharmacological studies
 It involves:
 Screening of extracts for specific chemical class
 Using chemical reagents for detection
 Chemically-guided fractionation
 Results:
 Minute/Trace components are mostly missed (detection limits)
 Unknown natural compounds are certainly missed
 Mostly: No biological activity found
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2. Bioactivity Approach
 Extracts are screened for a specific therapeutic activity using
mostly in-vitro bioassay(s).
 Only those possessing a bioactivity are fractionated
 Active fractions are further fractionated to isolate the active
compounds in pure form
 Followed by characterization of its structure
 Results: often leads to the finding of highly potent, minor, novel
compounds

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Factors Affecting the Quality
of Herbs
 There is increasing demand to maintain the
quality of herbal drugs
 The increasing demand for herbal medicines in both
developing and developed countries
 Reproducible quality of any herbal remedy
shall ensure the proper control of the
starting material is most essential
 There are several factors which affect the
quality of herbal drugs
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A. Authentication and Reproducibility

of Herbal Ingredients
 Herbal ingredients must be accurately identified by
 macroscopical and microscopical characteristics, and
 compared with authentic material or an accurate description of
authentic herbs
 It is essential that herbal ingredients be referred to by
their binomial Latin names of genus and species
 Only permitted synonyms should be used
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B. Inter/Intra Species Variation in

Plants
 There are considerable inter- and intraspecies variations
in different plants
 primary and secondary metabolite varies

 This results in variation of the individual constituents

and thereby causes difficulties in standardization.
 All of these variations are genetically controlled
 related to the country of origin for that particular species
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C. Environmental Factors
• Factors such as
• climate
• altitude
• Rainfall
• other conditions responsible for the growth of plants
• These factors affect the quality of herbal ingredients present in a
particular species
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C1. Solar Radiation

 The ultraviolet region is essential for the photosynthesis
of plants
 Particular region of the ultraviolet range is harmful to the body of the plant
(UV-B region 280–315 nm)
 The plant needs to protect itself from these rays
 it produces phenylpropanoids, that is, flavonoids, anthocyanins,
hydroxycinnamic acids and their esters, anthocyanidins, and tannins in
increased quantities
 These compounds provide protection to the plant
against pathogenic and herbivorous attacks and
ultraviolet radiation
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• In addition, these compounds have

• Antifungal
• Antibacterial
• Antiviral
• Antiinflammatory
• Antioxidant, Antitumor
• Antihepatotoxic
• Antilipolytic,
• Vasodilator
• Immunostimulant,
• Antiallergic activities

• Other than the above compounds, there are other classes of

compounds for which production is enhanced due to
environmental stresses
• eg. glycol-alkaloids (α-solanine and α-chalconine)
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C2. Soil Nutrients

 The nutrient supply to the plant is an important factor for
controlling the secondary metabolite profile
 If the soil is nutrient rich then the production of nitrogen
containing metabolites is possible
 Alkaloids
 Cyanogenetic glycosides
 A limited phosphate supply in the soil enhances the production of
anthocyanidin
 Inadequate iron supply results in enhanced production of
phenolics
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D. Plant Parts Used

• The active constituents vary between the different parts of a
plant
• It is not uncommon for an herbal ingredient to be adulterated
with parts of the plant that are not normally utilized
• Exhausted plant parts of the same physical appearance are
mixed to increase the weight of the supplied herbal ingredient,
causing adulteration
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• Young plant parts contained a greater level of alkaloids

compared with old parts
• The levels of saponin are found to be comparatively greater in
the stem over the leaves
• Old leaves contain a high level of phenolic content as compared
with old stems.
• Table: Cinnamaldehyde Content Variation in Different Parts of
Cinnamomum sp.
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E. Time of Harvesting
• While collecting a particular herbal ingredient, the optimum time
for harvesting should be specified
F. Post Harvesting Factors
 The treatment of the collected herbal raw materials such as
storage and transport, can greatly affect the quality of an herbal
ingredient
 Improper storage after collection may result in microbial
contamination and processes, such as drying, may result in a loss
of thermolabile active constituents
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G. DETERIORATION OF HERBAL DRUGS

• The storage conditions affect the stability of the herbs
and the secondary metabolites present
• light
• Humidity
• Oxygen
• Temperature

• Also, microbial growth in the phytopharmaceuticals tells

upon the quality of the products
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G1. Light
• Wormseed (Dysphania ambrosioides) contains Santonin
as the principal constituent
• When it is exposed to light, it undergoes photodecomposition and
becomes black.

• Rhubarb powder undergoes decomposition in clear

glass jars and becomes reddish
• Photosensitive herbal drugs should be stored in light-
resistant containers.
• If that is not possible, then the bottle should be stored in light-resistant
boxes
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G2. Moisture
• Some drugs do not absorb moisture from the atmosphere
and are thus called air-dry.
• These drugs do not need to be kept in air-tight containers
• Depending on the %RH, these drugs contain 10%–12% moisture

• The presence of moisture in drugs results in reactivation of

enzymes in the drug
• resulting in decomposition of the constituents.

• Moisture-sensitive drugs need to be stored in the presence

of siccatives, such as calcium chloride, calcium sulfate, or
sodium sulfate
• Example: Squill
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G3. Temperature
• Several enzymatic breakdowns of the secondary metabolites of
the plants take place faster in response to temperature
elevation up to 45 °C
• Essential oil-bearing plants lose volatile constituents
• Absorbent cotton wools, when subjected to elevated temperature, undergo
degradation and may become nonabsorbent

G4. Airic Oxidation

• Atmospheric oxygen causes direct oxidation of the secondary
metabolites of herbal medicinal products.
• Linseed oil, turpentine oil, and lemon oils become resins
• Cannabinol, Cannabis indica
 In addition to the above components bacteria and moulds, insects , mites and nomatodes