PHARMACOGNOSY INTRO, HISTORY ANS SCOPE.pdf

V.BASKAR ANAND RAJ. PROFESSOR, PHARMACOGNOSY
KMCT COLLEGE OF PHARMACY, MALAPURAM, KERALA.
PHARMACOGNOSY
DEFINITION
Pharmacognosy is systematic study of these crude drugs obtained from natural origin like plant,
animal and minerals. Pharmacognosy can be defined as branch of science which involves detail study
of drugs obtained from natural origin including name, habitat, collection, cultivation, macroscopy,
microscopy, physical properties, chemical constituents, therapeutic actions, uses and adulterants.
The word pharmacognosy is derived from two words, pharmakon means medicine (drug) and
gignosco means to acquire knowledge of something. Prof. John Schimidt coined the term
pharmacognosy in his book Lehrbuch der MateriaMedica. Earlier subject was known as
‘Materiamedica’. It includes systematic study of crude drugs from nature. Study of pharmacognosy
includes the history, distribution, cultivation, collection, processing and preservation. It also includes
the study of physical, chemical and structural characters and the safe uses of crude drugs. In short,
pharmacognosy is study of drugs from natural origin. Drugs from natural origin can be obtained by
plants, animals (terrestrial as well as marine) and minerals.
HISTORY AND DEVELOPMENT OF PHARMACOGNOSY
The history of pharmacognosy is as old as human existence. To know the future one should know
the past. The word ‘drug’ is derived from Latin term Droog means dried, when dried plants were
commonly used as medicine. Broadly, history of pharmacognosy can be classified into three major
stages. First stage before eighteenth century, very few documents and recorded evidences are
available showing use of natural products by human. Second stage involves nineteenth century,
which is the time when basic subject has evolved. In this century, the name pharmacognosy came
into practice. Initially the subject was more likely to descriptive botany of medicinal plants. But as
the time progress, it changes the course and encompasses extraction, isolation and other advances
techniques. In twentieth century, which may be considered as third stage of development, series of
discoveries resulted in complete metamorphosis of the subject. From last two decades,
pharmacognosy is studied in more systematic manner. As herbal wave continue to sweep the world,
importance of natural product is at the pinnacle. People are expecting natural products to fit in
modern framework. As a result of this there are series of new herbal formulations in the market. The
ancient Egyptians documented their knowledge about medicine on paper made from
Cyperusaquaticus commonly called acquatic sage or papyrus. Papyrus Ebers (around 1500 BC), Berlin
Papyrus, Edwin Smith Paprus, KahunMedicak Papyrus are some of the oldest handbooks which
contain information of illness and treatments. In ancient Egypt and Mesopotamia clay tablets were
used to document knowledge of drugs which are dating back to 3000 BC. Ancient India, information
about drugs was documented in several Ayurvedic texts which still exist. Apart from Atharvaveda
there are several books like CharakSamhita, SushrutSamhita, AstangHridaya, MadhavNidan and
BhavaPrakash. In eighteenth century, pharmacognosy was much closely related to botany. In old
days, drugs from natural origin were used in crude form as powder or decoction. Later in nineteenth
century, development in science has expanded arena of pharmacognosy. Now a day’s
pharmacognosy has become a kind of multidisciplinary subject which embarrasses phytochemistry,
analytical pharmacognosy, pharmacotherapy, medicinal plant biotechnology, herbal formulations
and nutraceuticals. Zoopharmacognosy is branch of pharmacognosy which involves observation of

animal behavior for discovery and development of new drugs. Now a day’s drug from natural origin
are studied, formulated and regulated in the framework of modern medicine.
1.Sumerians and Akkadians (3rd millennium BC) 2.Egyptians (Ebers papyrus, 1550 BC) 3.Hippocrates
(460-377 BC) “The Father of Medicine” 4.Dioscorides (40-80 AD) “De MateriaMedica” (600 medicinal
plants) 5.The Islamic era IbnAltabari (770−850) ”‫“ﺳودرﻓﮭﻣﻛﺣﻼ‬ 6.Ibn Sina (980-1037) "” ‫ﻧوﻧﺎﻗﻼﯾﻔﺑطﻼ‬
7 .Ibn
Albitar (1148-1197) ” ‫ﻋﻣﺎﺟﻼﺗﺎدرﻓﻣﻠﺔﯾودﻷاةﯾذﻏﻸاو‬
“
8 .The era of European exploration (16th and 17th
century) 9.The 18th century, Pharmacognosy: oJohann Adam (1759-1809) :surgeon and
ophthalmologist" 10.In 1811 his Lehrbuch der MateriaMedica was published, which was a work on
medicinal plants and their properties.11. Linnaeus (naming and classifying plants) 12.At the end of
the 18th century, crude drugs were still being used as powders, simple extracts, or tinctures 13.The
era of pure compounds (In 1803, a new era in the history of medicine) 14.ƒ Isolation of morphine
from opium ƒ Strychnine (1817) ƒ Quinine and caffeine (1820) ƒ Nicotine (1828) ƒ Atropine (1833) ƒ
Cocaine (1855) 15.In the 19th century, the chemical structures of many of the isolated compounds
were determined 16.In the 20th century, the discovery of important drugs from the animal kingdom,
particularly hormones and vitamins. •microorganisms have become a very important source of
drugs
SCOPE OF PHARMACOGNOSY
Pharmacognosy is critical in development of different disciplines of science. A pharmacognosist
should possess a sound knowledge of the terms used to describe the vegetable and animal drugs as
covered under botany and zoology, respectively. The knowledge of plant taxonomy, plant breeding,
plant pathology and plant genetics is helpful in the development of cultivation technology for
medicinal and aromatic plants. Plant - chemistry (phytochemistry) has undergone significant
development in recent years as a distinct discipline. It is concerned with the enormous variety of
substances that are synthesized and accumulated by plants and the structural elucidation of these
substances. Extraction, isolation, purification and characterization of phytochemicals from natural
sources are important for advancement of medicine system. The knowledge of chemotaxonomy,
biogenetic pathways for formation of medicinally active primary and secondary metabolites, plant
tissue culture and other related fields is essential for complete understanding of Pharmacognosy.
One should have the basic knowledge of biochemistry and chemical engineering is essential for
development of collection, processing and storage technology of crude drugs.
1. Pharmacognosy is important branch of pharmacy which is playing key role in new drug discovery
and development by using natural products. Pharmacognosy has given many leads for new drug
discovery and development.
2. It is an important link between modern medicine systems (allopathy) and traditional system of
medicine. It is part medicinal system which is affordable as well as accessible to common man. As
part of integrative system of medicine, pharmacognosy can help to increase effectiveness of modern
medicine system.
3. It is acting as bridge between pharmacology, medicinal chemistry and pharmacotherapeutics and
also pharmaceutics. It also bridges pharmaceutics with other pharmacy subjects.

4. More than 60 percent of world population is still using natural product for their primary
healthcare needs. Pharmacognosy can provide safe and effective drugs in combination with modern
medicine system.
5. Pharmacognosy includes knowledge about safe use of herbal drugs including toxicity, side effects,
drug interaction thereby increasing effectiveness of modern medicine.
6. Pharmacognosy is an important link between pharmacology and medicinal chemistry. As a result
of rapid development of phytochemistry and pharmacological testing methods in recent years, new
plant drugs are finding their way into medicine as purified phytochemicals, rather than in the form
of traditional galenical preparations.
7. Pharmacognosy is the base for development of novel medicines. Most of the compounds obtained
from natural product serve as prototype or base for development of new drug which are more active
and less toxic.
8. By means of pharmacognosy, natural products can be dispensed, formulated and manufactured in
dosage forms acceptable to modern system of medicine.
9. There are vast number of plant and animal species which are not studied systematically.
10. Development of pharmacognosy also leads to development of botany, taxonomy, plant
biotechnology, plant genetics, plant pathology, pharmaceutics, pharmacology, phytochemistry and
other branches of science.

CULTIVATION
Methods of Plant Propagation
Medicinal plants can be propagated by two usual methods as applicable to nonmedicinal plants or
crops.
These methods are referred as sexual method and asexual method. Each of these methods has
certain advantages, and also, disadvantages.
1. Sexual method (seed propagation)
In case of sexual method, the plants are raised from seeds and such plants are known as seedlings.
The sexual method of propagation enjoys following advantages:
1.Seedlings are longlived (in case of perennial drugs) and bear more heavily (in case of fruits). Plants
are more sturdier.
2.Seedlings are comparatively cheaper and easy to raise.
3.Propagation from seed has been responsible for production of some chanceseedlings of highly
superior merits which may be of great importance to specific products, such as orange, papaya, etc.
4.In case of plants where other vegetative methods cannot be utilized, propagation from seeds is the
only method of choice.
Sexual method suffers from following limitations
1.Generally, seedling trees are not uniform in their growth and yielding capacity, as compared to
grafted trees.
2.They require more time to bear, as compared to grafted plants.
3.The cost of harvesting, spraying of pesticides, etc. is more as compared to grafted trees.
4.It is not possible to avail of modifying influence of root stocks on scion, as in case of vegetatively
propagated trees.
For propagation purpose, the seeds must be of good quality. They should be capable a high
germination rate, free from diseases and insects and also free from other seeds, used seeds and
extraneous material. The germination capacity of seeds is tested by rolled towel test, excised
embryo test, etc. The seeds are preconditioned with the help of scarcification to make them
permeable to water and gases, if the seeds are not to be germinated in near future, they should be
stored in cool and dry place to maintain their germinating power. Long storage of seeds should be
avoided.
Before germination, sometimes a chemical treatment is given with stimulants like gibberellins,
cytokinins, ethylene, thiourea, potassium nitrate or sodium hypochlorite. Gibbereilic acid (GA3)
promotes germination of some type of dormant seeds and stimulates the seedling growth. Many

freshly harvested dormant seeds germinate better after soaking in potassium nitrate solution.
Thiourea is used for those seeds which do not germinate in dark or at high temperatures.
Methods of sowing the seeds
Numerous methods of sowing the seeds of the medicinal plants are in practice. Few of them using
seeds for cultivation are described:
Broadcasting: If the seeds are extremely small the sowing is done by broadcasting method. In this
method the seeds are scattered freely in well prepared soil for cultivation. The seeds only need
raking. If they are deeply sown or covered by soil, they may not get germinated. Necessary thinning
of the seedlings is done by keeping a specific distance, e.g. Isabgol, Linseed, Sesame, etc.
Dibbling: When the seeds of average size and weight are available, they are sown byplacing in holes.
Number of seeds to be put in holes vary from three to five, depending upon the vitality, sex of the
plants needed for the purpose and the size of the plant coming out of the seeds.
For example, in case of fennel four to five fruits are put in a single hole keeping suitable distance in
between two holes. In case of castor, only two to three seeds are put. In case of papaya, the plants
are unisexual and only female plants are desired for medicinal purposes. Hence, five to six seeds are
put together and after the sex of the plants is confirmed, healthy female plant is allowed to grow
while male plants and others are removed.
Miscellaneous: Many a times the seeds are sown in nursery beds. The seedlings thus produced are
transplanted to farms for further growth, such as cinchona, cardamom, clove, digitalis, capsicum,
etc.
Special treatment to seeds: To enhance germination, special treatments to seeds may be given, such
as soaking the seeds in water for a day e.g. castor seeds and other slowgerminating seeds.
Sometimes, seeds are soaked in sulphuric acid e.g. henbane seeds. Alternatively, testa is partially
removed by grindstone or by pounding seeds with coarse sand, e.g. Indian senna. Several plant
hormones like gibberellins, auxins are also used.
2. Asexual method
In case of asexual method of vegetative propagation, the vegetative part of a plant, such as stem or
root, is placed in such an environment that it develops into a new plant.
Asexual propagation enjoys following advantages:
1. There is no variation between the plant grown and plant from which it is grown. As such, the
plants are uniform in growth and yielding capacity. In case of fruit trees, uniformity in fruit quality
makes harvesting and marketing easy.
2. Seedless varieties of fruits can only be propagated vegetatively e.g. grapes, pomegranates and
lemon.
Plants start bearing earlier as compared to seedling trees.
Budding or grafting encourages diseaseresistant varieties of plants.

Modifying influence of rootstocks on scion can be availed of.
Inferior or unsuitable varieties can be overlooked.
It suffers from following disadvantages:
1. In comparison to seedling trees, these are not vigorous in growth and are not longlived.
2. No new varieties can be evolved by this method.
Asexual method of vegetative propagation consists of three types:
a) Natural methods of vegetative propagation.
b) Artificial methods of vegetative propagation.
Aseptic method of micropropagation (tissueculture).
Natural methods of vegetative propagation: It is done by sowing various parts of the plants in well
prepared soil. The following are the examples of vegetative propagation:
Bulbs: Squill, Garlic
Tubers: Rhizomes: Stolons: Aconite, Jalap, Potato Ginger, Trumeric, Liquorice
b) Artificial methods of vegetative propagations: Themethod by which plantlets or seedlings are
produced from vegetative part of the plant by using some technique or process is known as artificial
method of vegetative propagation. These methods are classified as under:
1.Cuttings
i.Stem cuttings
Citrus, camellia. Orange, rose and bougainvillea.
ii.Root cuttings: Brahmi.
iii.Leaf cuttings: Bryophyllum.
2.Layering
i.Simple layering: Guava, lemon
ii.Serpentine layering: jasmine, clematis
3.Grafting : Apple and rose
(c) Aseptic methods of micropropagation (tissue culture)
It is a novel method for propagation of medicinal plants. In micropropagation, the plants are
developed in an artificial medium under aseptic conditions from fine pieces of plants like single cells,

callus, seeds, embryos, root tips, shoot tips, pollen grains, etc. They are also provided with
nutritional and hormonal requirements.
COLLECTION AND PROCESSING OF HERBAL DRUGS
COLLECTION OF HERBAL DRUGS
Collection is the most important step which comes after cultivation. Drugs are collected from wild or
cultivated plants and the tasks for collection depends upon the collector, whether he is a skilled or
unskilled labour. Drugs should be collected when they contain maximum amount of constituents in a
highly scientific manner. The season at which each drug is collected is so important, as the amount,
and sometimes the nature, of the active constituents could be changed throughout the year. For
example, Rhubarb is collected only in summer seasons because no anthraqui-none derivatives would
be present in winter season but anthranols are converted to anthraquinones during summer. Not
only the season but also the age of the plant should be taken in to great consideration since it
governs not only the total amount of active constituents produced in the plants but also the
proportions of the constituents of the active mixture. High proportion of polygon in young plants of
peppermint will be replaced by Mentone and menthol and reduction in the percentage of alkaloids
in datura as the plant ages are examples of the effect of aging in plants.
Moreover the composition of a number of secondary plant metabolites varies throughout the day
and night, and it is believed that some inter conversion would happen during day and night.
Generally the leaves are collected just before the flowering season, e.g. vasaka, digitalis, etc., at this
time it is assumed that the whole plant has come to a healthy state and contain an optimum amount
of metabolites, flowers are collected before they expand fully, e.g. clove, saffron, etc., and
underground organs as the aerial parts of plant cells die, e.g. liquorice, rauwolfia, etc. Since it is very
difficult to collect the exact medicinally valuable parts, the official pharmacopoeia’s has fixed certain
amount of foreign matter that is permissible with drug. Some fruits are collected after their full
maturity while the others are collected after the fruits are ripe. Barks are usually col-lected in spring
season, as they are easy to separate from the wood during this season. The barks are collected using
three techniques, felling (bark is peeled off after cutting the tree at base), uprooting (the
underground roots are dug out and barks are collected from branches and roots) and coppicing
(plant is cut one metre above the ground level and barks are removed).
Underground parts should be collected and shaken, dusted in order to remove the adhered soil;
water washing could be done if the adhered particles are too sticky with plant parts. The
unorganized drugs should be collected from plants as soon as they oozes out, e.g. resins, latex,
gums, etc. Discoloured drugs or drugs which were affected by insects should be rejected.
HARVESTING OF HERBAL DRUGS
Harvesting is an important operation in cultivation tech-nology, as it reflects upon economic aspects
of the crude drugs. An important point which needs attention over here is the type of drug to be
harvested and the pharmacopoeial standards which it needs to achieve. Harvesting can be done
efficiently in every respect by the skilled workers. Selectivity is of advantage in that the drugs other

than genuine, but similar in appearance can be rejected at the site of collection. It is, however, a
laborious job and may not be economical. In certain cases, it cannot be replaced by any mechanical
means, e.g. digitalis, tea, vinca and senna leaves. The underground drugs like roots, rhizomes,
tubers, etc. are harvested by mechanical devices, such as diggers or lifters. The tubers or roots are
thoroughly washed in water to get rid of earthy-matter. Drugs which constitute all aerial parts are
harvested by binders for economic reasons. Many a times, flowers, seeds and small fruits are
harvested by a special device known as seed stripper. The technique of beating plant with bamboos
is used in case of cloves. The cochineal insects are collected from branches of cacti by brushing. The
seaweeds producing agar are harvested by long handled forks. Peppermint and spearmint are har-
vested by normal method with mowers, whereas fennel, coriander and caraway plants are uprooted
and dried. After drying, either they are thrashed or beaten and the fruits are separated by
winnowing. Sometimes, reaping machines are also used for their harvesting.
Harvesting can be done efficiently-
1. In every respect by the skilled workers. Selectivity is of advantage in that the drugs other than
genuine, but similar in appearance can be rejected at the site of collection. It is, however, a laborious
job and may not be economical. In certain cases, it cannot be replaced by any mechanical means,
e.g. digitalis, tea, vinca and senna leaves.
2. The underground drugs like roots, rhizomes, tubers, etc. are harvested by mechanical devices,
such as diggers or lifters. The tubers or roots are thoroughly washed in water to get rid of earthy-
matter.
3. Drugs which constitute all aerial parts are harvested by binders for economic reasons.
4. Many a times, flowers, seeds and small fruits are harvested by a special device known as seed
stripper.
5. The technique of beating plant with bamboos is used in case of cloves.
6. The cochineal insects are collected from branches of cacti by brushing.
7. The seaweeds producing agar are harvested by long handled forks.
DRYING OF CRUDE DRUGS
Before marketing a crude drug, it is necessary to process it properly, so as to preserve it for a longer
time and also to acquire better pharmaceutical elegance. This process-ing includes several
operations or treatments, depending upon the source of the crude drug (animal or plant) and its
chemical nature. Drying consists of removal of suffi-cient moisture content of crude drug, so as to
improve its quality and make it resistant to the growth of microorgan-isms. Drying inhibits partially
enzymatic reactions. Drying also facilitates pulverizing or grinding of a crude drug. In certain drugs,
some special methods are required to be followed to attain specific standards, e.g. fermentation in
case of Cinnamomum zeylanicum bark and gentian roots. The slicing and cutting into smaller pieces
is done to enhance drying, as in case of glycyrrhiza, squill and calumba. The flowers are dried in
shade so as to retain their colour and volatile oil content. Depending upon the type of chemical
constituents, a method of drying can be used for a crude drug.

Drying can be of two types –
(1) natural (sun drying) and (2) artificial.
1.Natural Drying (Sun-Drying) In case of natural drying, it may be either direct sun-drying or in the
shed. If the natural colour of the drug (digitalis, clove, senna) and the volatile principles of the drug
(pep-permint) are to be retained, drying in shed is preferred. If the contents of the drugs are quite
stable to the temperature and sunlight, the drugs can be dried directly in sunshine (gum acacia,
seeds and fruits).
2.Artificial Drying Drying by artificial means includes drying the drugs in (a) an oven;
i.e. tray-dryers; (b) vacuum dryers and (c) spray dryers.
a. Tray dryers The drugs which do not contain volatile oils and are quite stable to heat or which need
deactivation of enzymes are dried in tray dryers. In this process, hot air of the desired temperature is
circulated through the dryers and this facili-tates the removal of water content of the drugs
(belladonna roots, cinchona bark, tea and raspberry leaves and gums are dried by this method).
b. Vacuum dryers The drugs which are sensitive to higher temperature are dried by this process, e.g.
Tannic acid and digitalis leaves.
c. Spray dryers Few drugs which are highly sensitive to atmospheric condi-tions and also to
temperature of vacuum-drying are dried by spray-drying method. The technique is followed for
quick drying of economically important plant or animal constituents, rather than the crude drugs.
Examples of spray drying are papaya latex, pectin, tannins, etc.
GARBLING (DRESSING)
The next step in preparation of crude drug for market after drying is garbling. This process is desired
when sand, dirt and foreign organic parts of the same plant, not constituting drug are required to be
removed. This foreign organic matter (extraneous matter) is removed by several ways and means
available and practicable at the site of the preparation of the drugs. If the extraneous matter is
permitted in crude drugs, the quality of drug surfers and at times, it dose not pass pharmacopoeia
limits. Excessive stems in case of lobelia and stramonium need to be removed, while the stalks, in
case of cloves are to be deleted. Drugs constituting rhizomes need to be separated carefully from
roots and rootlets and also stem bases. Pieces of iron must be removed with the magnet in case of
castor seeds before crushing and by shifting in case of vinca and senna leaves. Pieces of bark should
be removed by peeling as in gum acacia.
PACKING OF CRUDE DRUGS
The morphological and chemical nature of drug, its ultimate use and effects of climatic conditions
during transportation and storage should be taken into consideration while packing the drugs. Aloe
is packed in goat skin. Colophony and balsam of tolu are packed in kerosene tins, while asafoetida is
stored in well closed containers to prevent loss of volatile oil. Cod liver oil, being sensitive to sun-
light, should be stored in such containers, which will not have effect of sunlight, whereas, the leaf
drugs like senna, vinca and others are pressed and baled. The drugs which are very sensitive to
moisture and also costly at the same time need special attention, e.g. digitalis, ergot and squill. Squill

becomes flexible; ergot becomes susceptible to the microbial growth, while digitalis looses its
potency due to decomposition of glycosides, if brought in contact with excess of moisture during
storage. Hence, the chemicals which absorb excessive moisture (desiccating agents) from the drug
are incorporated in the containers. Colophony needs to be packed in big masses to control
autooxidation. Cinnamon bark, which is available in the form of quills, is packed one inside the other
quill, so as to facilitate trans-port and to prevent volatilization of oil from the drug. The crude drugs
like roots, seeds and others do not need special attention and are packed in gunny bags, while in
some cases bags are coated with polythene internally. The weight of certain drugs in lots is also kept
constant e.g. Indian opium.
STORAGE OF CRUDE DRUGS
Preservation of crude drugs needs sound knowledge of their physical and chemical properties. A
good quality of the drugs can be maintained, if they are preserved properly. All the drugs should be
preserved in well closed and, possibly in the filled containers. They should be stored in the premises
which are water-proof, fire proof and rodent-proof. A number of drugs absorb moisture during their
storage and become susceptible to the microbial growth. Some drugs absorb moisture to the extent
of 25% of their weight. The moisture, not only increases the bulk of the drug, but also causes
impairment in the quality of crude drug. The excessive moisture facilitates enzymatic reactions
resulting in decomposition of active constituents e.g. digitalis leaves and wild cherry bark. Gentian
and ergot receive mould infestation due to excessive moisture. Radiation due to direct sun-light also
causes destruction of active chemical constituents, e.g. ergot, cod liver oil and digitalis. Form or
shape of the drug also plays very important role in preserving the crude drugs. Colophony in the
entire form (big masses) is preserved nicely, but if stored in powdered form, it gets oxidized or
looses solubility in petroleum ether. Squill, when stored in powdered form becomes hygroscopic and
forms rubbery mass on prolonged exposure to air. The fixed oil in the powdered ergot becomes
rancid on storage. In order to maintain a good quality of ergot, it is required that the drug should be
defatted with lipid solvent prior to storage. Lard, the purified internal fat of the abdomen of the hog,
is to be preserved against rancidity by adding siam benzoin. Atmospheric oxygen is also destructive
to several drugs and hence, they are filled completely in well closed containers, or the air in the
container is replaced by an inert gas like nitrogen; e.g. shark liver oil, papain, etc. drugs
Apart from protection against adverse physical and chem-ical changes, the preservation against
insect or mould attacks is also important. Different types of insects, nematodes, worms, moulds and
mites infest the crude drugs during storage. Some of the more important pests found in are rium),
Lepidoptera (Ephestia Coleoptera (Stegobium kuehniella and Tinea paniceum and Calandrum
pellionella), and Archnida grana or mites (Tyroglyphus farinae and Glyophagus domesticus). They
can be prevented by drying the drug thoroughly before storage and also by giving treatment of
fumigants. The common fumigants used for storage of crude drugs are methyl bromide, carbon
disulphide and hydrocyanic acid. At times, drugs are given special treament, such as liming of the
ginger and coating of nutmeg. Temperature is also very important factor in preservation of the
drugs, as it accelerates several chemical reactions leading to decomposition of the constituents.
Hence, most of the drugs need to be preserved at a very low temperature. The costly
phytopharmaceuticals are required to be preserved at refrigerated temperature in well closed
containers. Small quantities of crude drugs could be readily stored in air-tight, moisture proof and

light proof containers such as tin, cans, covered metal tins, or amber glass containers. Wooden
boxes and paper bags should not be used for storage of crude drugs.

CLASSIFICATION OF CRUDE DRUGS
The most important natural sources of drugs are higher plant, microbes and animals and marine
organisms. Some useful products are obtained from minerals that are both organic and inorganic in
nature. In order to pursue (or to follow) the study of the individual drugs, one must adopt some
particular sequence of arrangement, and this is referred to a system of classification of drugs. A
method of classification should be:
a) Simple,
b) Easy to use, and
c) Free from confusion and ambiguities.
Because of their wide distribution, each arrangement of classification has its own merits and
demerits, but for the purpose of study the drugs are classified in the following different ways:
1. Alphabetical classification
2. Taxonomical classification
3. Morphological classification
4. Pharmacological classification
5. Chemical classification
6. Chemotaxonomical classification
7. Serotaxonomical classification
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). Some of the pharmacopoeias, dictionaries and
reference books which classify crude drugs according to this system are as follows:
1. Indian Pharmacopoeia
2. British Pharmacopoeia
3. British Herbal Pharmacopoeia
4. United States Pharmacopoeia and National Formulary
5. British Pharmaceutical Codex
6. European Pharmacopoeia
In European Pharmacopoeia these are arranged according to their names in Latin where in United
States Pharmaco-poeia (U.S.P.) and British Pharmaceutical Codex (B.P.C.), these are arranged in
English.
Merits
• It is easy and quick to use.
• There is no repetition of entries and is devoid of con-fusion.

• In this system location, tracing and addition of drug entries is easy.
Demerits
There is no relationship between previous and successive drug entries.
Examples: Acacia, Benzoin, Cinchona, Dill, Ergot, Fennel, Gentian, Hyoscyamus, Ipecacuanha, Jalap,
Kurchi, Liquorice, Mints, Nux vomica, Opium, Podophyllum, Quassia, Rauwolfia, Senna, Vasaka, Wool
fat, Yellow bees wax, Zeodary.
TAXONOMICAL CLASSIFICATION
All the plants possess different characters of morphologi-cal, microscopical, chemical,
embryological, serological and genetics. In this classification the crude drugs are classified according
to kingdom, subkingdom, division, class, order, family, genus and species as follows.
Class: Angiospermae (Angiosperms) are plants that produce flowers and Gymnospermae
(Gymnosperms) which don’t produce flowers.
Subclass: Dicotyledonae (Dicotyledons, Dicots) are plants with two seed leaves; Monocotyledonae
(Monocotyledons, Monocots) with one seed leaf.
Superorder: A group of related plant families, classified in the order in which they are thought to
have developed their dif-ferences from a common ancestor. There are six superorders in the
Dicotyledonae (Magnoliidae, Hamamelidae, Caryophyl-lidae, Dilleniidae, Rosidae, Asteridae), and
four superorders in the Monocotyledonae (Alismatidae, Commelinidae, Arecidae, and
Liliidae). 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.
Family: Each order is divided into families. These are plants with many botanical features in
common, and are the highest classification normally used. At this level, the similarity between plants
is often easily recognizable by the layman. Modern botanical classification assigns a type plant to
each family, which has the particular characteristics that 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 recognize only 150 or so families, preferring to classify other similar plants as subfamilies,
while others recognize 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.
Subfamily: The family may be further divided into a number of subfamilies, which group together
plants within the family that have some significant botanical differences. The names of the
subfamilies end in –oideae.
Tribe: A further division of plants within a family, based on smaller botanical differences, bin still
usually comprising many different plants. The names of the tribes end in –eae.

Subtribe: A further division based on even smaller botanical differences, often only recognizable to
botanists. The names of the subtribes end in –inae.
Genus: This is the part of the plant name that is most famil-iar; the normal name that you give a
plant—Papaver (Poppy), Aquilegia (Columbine), and so on. The plants in a genus are often easily
recognizable as belonging to the same group.
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. Together, the genus and species name refer to only one plant, and they
are used to identify that particular plant. Sometimes, the species is further divided into subspecies
that contain plants not quite so distinct that they are classified as variet-ies. The name, of the
species should be written after the genus name, in small letters, with no capital letter.
Variety: A variety is a plant that is only slightly different from the species plant, but the differences
are not so insig-nificant as the differences in a form. The Latin is varietas, which is usually
abbreviated to var. The name follows the genus and species name, with var. before the individual
variety name.
Form: A form is a plant within a species that has minor botanical differences, such as the colour of
flower or shape of the leaves. The name follows the genus and species name, with form (or f.)
before the individual variety name.
Cultivar: A cultivar is a cultivated variety—a particular plant that has arisen either naturally or
through deliberate hybridization, and can be reproduced (vegetatively or by seed) to produce more
of the same plant.
The name follows the genus and species name. It is written in the language of the person who
described it, and should not be translated. It is either written in single quotation marks or has cv.
written in front of the name.
Merits
Taxonomical classification is helpful for studying evolution-ary developments.

Demerits
This system also does not correlate in between the chemical constituents and biological activity of
the drugs.
MORPHOLOGICAL CLASSIFICATION
In this system, the drugs are arranged according to the morphological or external characters of the
plant parts or animal parts, i.e. which part of the plant is used as a drug, e.g. leaves, roots, stem, etc.
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 pre-pared 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 unorga-nized drugs.
Aloe juice, opium latex, agar, gambir, gelatin, tragacanth, benzoin, honey, beeswax, lemon grass oil,
etc., are examples of unorganized drugs.
Organized drugs
Woods: Quassia, Sandalwood and Red Sandalwood.
Leaves: Digitalis, Eucalyptus, Gymnema, Mint, Senna, Spearmint, Squill, Tulsi, Vasaka, Coca, Buchu,
Hamamelis, Hyoscyamus, Belladonna, Tea.
Barks: Arjuna, Ashoka, Cascara, Cassia, Cinchona, Cinnamon, Kurchi, Quillia, Wild cherry.
Flowering parts: Clove, Pyrethrum, Saffron, Santonica, Chamomile.
Fruits: Amla, Anise, Bael, Bahera, Bitter Orange peel, Capsicum, Caraway, Cardamom, Colocynth,
Coriander, Cumin, Dill, Fennel, Gokhru, Hirda, Lemon peel, Senna pod, Star anise, Tamarind, Vidang.
Seeds: Bitter almond, Black Mustard, Cardamom, Colchi-cum, Ispaghula, Kaladana, Linseed, Nutmeg,
Nux vomica,Physostigma, Psyllium, Strophanthus, White mustard. Roots and Rhizomes: Aconite,
Ashwagandha, Calamus, Calumba, Colchicum corm, Dioscorea, Galanga, Garlic, Gention, Ginger,
Ginseng, Glycyrrhiza, Podophyllum, Ipecac, Ipomoea, Jalap, Jatamansi, Rauwolfia, Rhubarb,
Sassurea, Senega, Shatavari, Turmeric, Valerian, Squill.
Plants and Herbs: Ergot, Ephedra, Bacopa, Andrographis, Kalmegh, Yeast, Vinca, Datura, Centella.
Hair and Fibres: Cotton, Hemp, Jute, Silk, Flax.

Unorganized drugs
Dried latex: Opium, Papain
Dried Juice: Aloe, Kino
Dried extracts: Agar, Alginate, Black catechu, Pale catechu, Pectin
Waxes: Beeswax, Spermaceti, Carnauba wax
Gums: Acacia, Guar Gum, Indian Gum, Sterculia, Tra-gacenth
Resins: Asafoetida, Benzoin, Colophony, copaiba Gua-iacum, Guggul, Mastic, Coal tar, Tar, Tolu
balsam, Storax, Sandarac.
Volatile oil: Turpentine, Anise, Coriander, Peppermint, Rosemary, Sandalwood, Cinnamon, Lemon,
Caraway, Dill, Clove, Eucalyptus, Nutmeg, Camphor.
Fixed oils and Fats: Arachis, Castor, Chalmoogra, Coconut, Cotton seed, Linseed, Olive, Sesame,
Almond, Theobroma, Cod-liver, Halibut liver, Kokum butter.
Animal Products: Bees wax, Cantharides, Cod-liver oil, Gelatin, Halibut liver oil, Honey, Shark liver oil,
shellac, Spermaceti wax, wool fat, musk, Lactose.
Fossil organism and Minerals: Bentonite, Kaolin, Kiess-lguhr, Talc.
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 corelation of chemical
constituents with the therapeutic actions.
• Repetition of drugs or plants occurs.
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. Drugs like digitalis, squill and strophan-thus
having cardiotonic action are grouped irrespective of their parts used or phylogenetic relationship or
the nature of phytoconstituents they contain

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.
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. Irrespective of
the morphological or taxonomical char-acters, the drugs with similar chemical constituents are
grouped into the same group. The examples are shown in this table.

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.
CHEMOTAXONOMICAL CLASSIFICATION
This system of classification relies on the chemical similarity of a taxon, i.e. 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. This gives birth to entirely a new concept of
chemotaxonomy that utilizes chemical facts/characters for understanding the taxonomical status,
relationships and the evolution of the plants.
For example, tropane alkaloids generally occur among the members of Solanaceae, thereby, serving
as a chemot-axonomic marker. Similarly, other secondary plant metabo-lites can serve as the basis
of classification of crude drugs. The berberine alkaloid in Berberis and Argemone, Rutin in Rutaceae
members, Ranunculaceae alkaloids among its members, etc., are other examples.
It is the latest system of classification that gives more scope for understanding the relationship
between chemical constituents, their biosynthesis and their possible action.

SEROTAXONOMICAL CLASSIFICATION
The serotaxonomy can be explained as the study about the application or the utility of serology in
solving the taxo nomical problems. Serology can be defined as the study of the antigen– antibody
reaction. Antigens are those sub-stances which can stimulate the formation of the antibody.
Antibodies are highly specific protein molecule produced by plasma cells in the immune system.
Protein are carri-ers of the taxonomical information and commonly used as antigen in
serotaxonomy.
It expresses the similarities and the dissimilarities among different taxa, and these data are helpful in
taxonomy. It deter-mines the degree of similarity between species, genera, family, etc., by
comparing the reaction with antigens from various plant taxa with antibodies present against a given
taxon.
Serology helps in comparing nonmorphological charac-teristics, which helps in the taxonomical data.
This tech-nique also helps in the comparison of single proteins from different plant taxa.

Adulteration of Drugs of Natural Origin
Medicinal plants constitute an effective source of traditional (e.g. ayurvedic, chinese, homeopathy
and unani) and modern medicine. Herbal medicine has been shown to have genuine utility. Germany
and France, together represent 39% of the $14 billion global retail market. In India, about 80% of the
rural population depends on medicinal herbs and/or indigenous systems of medicine. In fact today,
approximately 70% of ‘synthetic’ medicines are derived from plants. Popularity among the common
people increased the usage of medicinal plants/herbal drugs. Herbal adulteration is one of the
common malpractices in herbal raw material trade. Adulteration is described as intentional
substitution with another plant species or intentional addition of a foreign substance to increase the
weight or potency of the product or to decrease its cost. In general, adulteration is considered as an
intentional practice. However, unintentional adulterations also exist in herbal raw-material trade
due to various reasons, and many of them are unknown even to the scientific community. The
present chapter deals with different intentional and unintentional adulterations, reasons behind
them and methods for easy identification of the spurious plant and authentication of the authentic
plant.
ADULTERATION
A treatise published two centuries ago (in 1820) on adulterations in food and culinary materials is a
proof for this practice as an age-old one. Due to adulteration, faith in herbal drugs has declined.
Adulteration in market samples is one of the greatest drawbacks in promotion of herbal products.
Many researchers have contributed in checking adulterations and authenticating them. It is
invariably found that the adverse event reports are not due to the intended herb, but rather due to
the presence of an unintended herb. Medicinal plant dealers have discovered the ‘scientific’
methods in creating adulteration of such a high quality that without microscopic and chemical
analysis, it is very difficult to trace these adulterations.
Definition: The term adulteration is defined as substituting original crude drug partially or wholly
with other similar-looking substances. The substance, which is mixed, is free from or inferior in
chemical and therapeutic property.
Types of Adulterants
Adulteration in simple terms is debasement of an article. The motives for intentional adulteration
are normally commercial and are originated mainly with the intension of enhancement of profits.
Some of the reasons that can be cited here are scarcity of drug and its high price prevailing in
market. The adulteration is done deliberately, but it may occur accidentally in some cases.
Adulteration involves different conditions such as deterioration, admixture, sophistication,
substitution, inferiority and spoilage. Deterioration is impairment in the quality of drug, whereas
admixture is addition of one article to another due to ignorance or carelessness or by accident.
Sophistication is the intentional or deliberate type of adulteration.
Substitution occurs when a totally different substance is added in place of original drug. Inferiority
refers to any substandard drug, and spoilage is due to the attack of microorganisms.
Unintentional Adulteration

Unintentional adulteration may be due to the following reasons:
1. confusion in vernacular names between indigenous systems of medicine and local dialects
2. lack of knowledge about the authentic plant
3. nonavailability of the authentic plant
4. similarity in morphology and or aroma
5. careless collection
6. other unknown reasons
Name confusion
In ayurveda, ‘Parpatta’ refers to Fumaria parviflora. In siddha, ‘Parpadagam’ refers to Mollugo
pentaphylla.
Owing to the similarity in the names in traditional systems of medicine, these two herbs are often
interchanged or adulterated or substituted. Because of the popularity of siddha medicine in some
parts of south India, traders in these regions supply M. pentaphylla as Parpatta/Parpadagam and the
north Indian suppliers supply F. parviflora. These two can be easily identified by the presence of pale
yellow to mild brown-coloured, thin wiry stems and small simple leaves of M. pentaphylla and black
to dark browncoloured, digitate leaves with narrow segments of F. parviflora. Casuarina equisetifolia
for Tamarix indica and Aerva lanata for Bergenia ciliata are some other examples of adulterations
due to confusion in names.
Lack of knowledge about authentic source
‘Nagakesar’ is one of the important drugs in ayurveda. The authentic source is Mesua ferrea.
However, market samples are adulterated with flowers of Calophyllum inophyllum. Though the
authentic plant is available in plenty throughout the Western Ghats and parts of the Himalayas,
suppliers are unaware of it.
There may also be some restrictions in forest collection. Due to these reasons, C. inophyllum (which
is in the plains) is sold as Nagakesar. Authentic flowers can be easily identified by the presence of
two-celled ovary, whereas in case of spurious flowers they are single celled.
Similarity in morphology
Mucuna pruriens is the best example for unknown authentic plant and similarity in morphology. It is
adulterated with other similar papilionaceae seeds. M. utilis (sold as white variety) and M.
deeringiana (sold as bigger variety) are popular adulterants. Apart from this, M. cochinchinensis,
Canavalia virosa and C. ensiformis are also sold in Indian markets. Authentic seeds are up to 1 cm in
length with shining mosaic pattern of black and brown colour on their surface. M. deeringiana and
M. utilis are bigger (1.5–2 cm) in size. M. deeringiana is dull black, whereas M. utilis is white or buff
coloured.

Lack of authentic plant
Hypericum perforatum is cultivated and sold in European markets. In India, availability of this species
is very limited. However, the abundant Indo-Nepal species H. patulum is sold in the name of H.
perforatum. Market sample is a whole plant with flowers, and it is easy to identify them
taxonomically. Anatomically, stem transverse section of H. perforatum has compressed thin phloem,
hollow pith and absence of calcium oxalate crystals. On the otherhand, H. patulum has broader
phloem, partially hollow pith and presence of calcium oxalate crystals.
Similarity in colour
It is well known that in course of time, drug materials get changed to or substituted with other plant
species. ‘Ratanjot’ is a recent-day example. On discussion with suppliers and nontimer forest
product (NTFP) contractors, it came to be known that in the past, roots of Ventilago madraspatana
were collected from Western Ghats, as the only source of ‘Ratanjot’. However, that is not the
practice now. It is clearly known that Arnebia euchroma var euchroma is the present source.
Similarity in yielding a red dye, A. euchroma substitutes V. madraspatana. The description to identify
these two is unnecessary because of the absence of V. madraspatana in market. Whatever is
available in the market, in the name of Ratanjot, was originated from A. euchroma.
Careless collections
Some of the herbal adulterations are due to the carelessness of herbal collectors and suppliers.
Parmelia perlata is used in ayurveda, unani and siddha. It is also used as grocery. Market samples
showed it to be admixed with other species (P. perforata and P. cirrhata). Sometimes, Usnea sp. is
also mixed with them. Authentic plants can be identified by their thallus nature.
Unknown reasons
‘Vidari’ is another example of unknown authentic plant. It is an important ayurvedic plant used
extensively. Its authentic source is Pueraria tuberosa, and its substitute is Ipomoea digitata.
However, market samples are not derived from these two. It is interesting to know that an
endangered gymnosperm Cycas circinalis is sold in plenty as Vidari. The adulterated materials
originated from Kerala, India. Although both the authentic plant and its substitute are available in
plenty throughout India, how C. circinalis became a major source for this drug is unknown. P.
tuberosa can be easily identified by the presence of papery flake-like tubers, I. digitata by the
presence of its concentric rings of vascular bundles and their adulterant C. circinalis by its leaf scars
and absence of vessel elements.
Intentional Adulteration
Intentional adulteration may be due to the following reasons:
1. adulteration using manufactured substances
2. substitution using inferior commercial varieties
3. substitution using exhausted drugs

4. substitution of superficially similar inferior natural substances
5. adulteration using the vegetative part of the same plant
6. addition of toxic materials
7. adulteration of powders
8. addition of synthetic principles
Adulteration using manufactured substances
In this type of adulteration the original substances are adulterated by the materials that are
artificially manufactured. The materials are prepared in a way that their general form and
appearance resemble with various drugs. Few examples are cargo of ergot from Portugal was
adulterated with small masses of flour dough moulded to the correct size and shape and coloured,
first using red ink, and then into writing ink. Bass-wood is cut exactly the required shape of nutmegs
and used to adulterate nutmegs. Compressed chicory is used in place of coffee berries. Paraffin wax
is coloured yellow and is been substituted for beeswax, and artificial invert sugar is used in place of
honey.
Substitution using inferior commercial varieties
In this type, the original drugs are substituted using inferior quality drugs that may be similar in
morphological characters, chemical constituents or therapeutic activity. For example hog gum or hog
tragacanth for tragacanth gum, mangosteen fruits for bael fruits, Arabian senna, obovate senna and
Provence senna are used to adulterate senna, ginger being adulterated with Cochin, African and
Japanese ginger. Capsicum annuum fruits and Japanese chillies are used for fruits of C. minimum.
Substitution using exhausted drugs
In this type of substitution the active medicaments of the main drugs are extracted out and are used
again. This could be done for the commodities that would retain its shape and appearance even
after extraction, or the appearance and taste could be made to the required state by adding
colouring or flavouring agents. This technique is frequently adopted for the drugs containing volatile
oils, such as: clove, fennel etc. After extraction, saffron and red rose petals are recoloured by
artificial dyes. Another example is balsam of tolu that does not contain cinnamic acid. The bitterness
of exhausted gentian is restored by adding aloes.
Substitution of superficially similar inferior natural substances
The substituents used may be morphologically similar but will not be having any relation to the
genuine article in their constituents or therapeutic activity. Ailanthus leaves are substituted for
belladona, senna, etc. saffron admixed with saff flower; peach kernels and apricot kernels for
almonds; clove stalks and mother cloves with cloves; peach kernel oil used for olive oil; chestnut
leaves for hamamelis leaves and Japan wax for beeswax are few examples for this type of
adulteration.

Adulteration using the vegetative part of the same plant
The presence of vegetative parts of the same plant with the drug in excessive amount is also an
adulteration. For example, epiphytes, such as mosses, liverworts and lichens that grow over the
barks also may occur in unusual amounts with the drugs, e.g. cascara or cinchona. Excessive amount
of stems in drugs like lobelia, stramonium, hamamelis leaves, etc. are few example for this type of
adulteration.
Addition of toxic materials
In this type of adulteration the materials used for adulteration would be toxic in nature. A big mass
of stone was found in the centre of a bale of liquorice root. Limestone pieces with asafetida, lead
shot in opium, amber-coloured glass pieces in colophony, barium sulphate to silvergrain cochineal
and manganese dioxide to blackgrain cochineal, are few examples in this adulteration.
Addition of synthetic principles
Synthetic pharmaceutical principles are used for market and therapeutic value. Citral is added to
lemon oil, whereas benzyl benzoate is added to balsam of Peru. Apart from these, the herbal
products labelled to improve sexual performance in men, when analysed, contained sildenafil. Brand
names included Actra-Rx, Yilishen, Hua Fo, Vinarol and Vasx, Sleeping Buddha containing estazolam,
Diabetes Angel containing glyburide and phenformin are few examples under this category.
Adulteration of powders
Powdered drugs are found to be adulterated very frequently. Adulterants used are generally
powdered waste products of a suitable colour and density. Powdered olive stones for powdered
gentian, liquorice or pepper; brick powder for barks; red sanders wood to chillies; dextrin for
powdered ipecacuanha, are few adulterants.

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