B Pharm II YEAR IV SEM

1. INTRODUCTION TO PHARMACOGNOSY
Prepared by
Mr. A. K. Daswad
Nanded Pharmacy College
(Degree), Nanded
UNIT-I

2. Definition
• The term Pharmacognosy has been derived from the 2
Greek words:
• i) pharmakon, which means a drug &
• ii) gnosis, which means knowledge of or gignosco, which means
to acquire knowledge of.
• Thus the full meaning of the term Pharmacognosy is `knowledge
of drugs’ or `to acquire knowledge of drugs’.

3. Pharmacognosy
•This term was introduced by C.A. Seydler, a
German medical student in 1815.
•Pharmakon- drug/medicine
•gnosis- knowledge
•gignosis- to acquire knowledge
•Pharmacognosy therefore means knowledge of drugs.

4. Introduction to pharmacognosy
• Pharmacognosy is an applied science which is concerned with acquiring
knowledge of crude drugs by the application of various scientific
disciplines
• Pharmacognosy deals with NATURAL products and is described as the
study of medicinal or therapeutic agents of natural origin, i.e.
• Plants
• Animals
• Mineral sources
• It also includes the study of their history, distribution, cultivation, collection,
preparation, identification, evaluation, preservation.

5. Introduction to Pharmacognosy
•A brief history of natural products in medicine
•Value of natural drug products
•Production of natural drug products
•The role of natural products in drug discovery

6. PHARMACOGNOSY, HISTORY AND SCOPE
Pharmacognosy is the study of crude drugs obtained from plants, animals and mineral
kingdoms and constituents obtained therefrom. Even though the science of
pharmacognosy has been practiced since the advent of mankind, the term
Pharmacognosy was first used by
C.A. Seydler, a German scientist, in 1815 in his book Analecta Pharmacognostica. It is
derived from two Latin words pharmakon, 'a drug', and gignosco, 'to acquire
knowledge of'. It means knowledge or science of drugs.
Drugs used in medicine today are either obtained from nature or are of synthetic origin.
Natural drugs are obtained from plants, animals or mineral kingdom. Drugs
from microorganisms like antibiotics were not known in the earlier times.
Synthetic drugs or syntheticals like aspirin, sulpha drugs, some vitamins and some
antibiotics are synthesized in laboratories from simple chemicals through various
chemical reactions.

7. • Natural drugs obtained from plants and animals are called drugs of
biological origin and the active principles, because of which they have
their therapeutic use, are produced in the living cells of plants and
animals.
• 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.
Most of the crude drugs used in medicine are obtained from plants and
only a small number comes from animal and mineral kingdoms.
Drugs obtained from plants consist of entire plants, while Senna leaves
and pods, nuxvomica seeds, ginger rhizome and cinchona bark are parts
of the plants

8. Though in a few cases, as in lemon and orange peels and in colchicum
corm, drugs are used in fresh condition, most of the drugs are dried after
collection.
Crude drugs may also be obtained by simple physical processes like drying
or extraction with water. Thus aloe is the dried juice of leaves of Aloe
species, opium is the dried latex from poppy capsules and black catechu is
the dried aqueous extract from the wood of Acacia catechu. Plant exudates
such as gums, resins and balsams, volatile oils and fixed oils are also
considered as crude
Further drugs used by physicians and surgeons or pharmacists, directly
drugs or indirectly, like cotton, silk, jute and nylon in surgical dressing or
kaolin, diatomite used in filtration of turbid liquid or gums, wax, gelatin,
agar used as pharmaceutical auxiliaries of flavoring or sweetening agents or
drugs used as vehicles or insecticides are treated in Pharmacognosy.

9. • Drugs obtained from animals are entire animals, as cantharides, glandular
products, like thyroid organ or extracts like liver extract. Similarly, fish
liver oils, musk, bees wax, certain hormones, enzymes and antitoxins are
products obtained from animal sources
Drugs are organized or unorganized.
• Organized drugs are direct parts of the plants and consist of cellular
tissues.
• Unorganized drugs, even though prepared from plants, are not the
direct parts of the plants and are prepared by some intermediary
physical processes like incision, drying, or extraction with water and
do not contain cellular tissue.
• Thus aloe, opium, catechu, gums, resins and other plant exudates are
unorganized drugs. Drugs from mineral sources are kaolin, chalk,
diatomite, the well-known Makardhwaj and other bhasmas of Ayurveda.

10. • HISTORY OF PHARMACOGNOSY
Diseases are born with man and drugs came into existence since a very early time to
remove the pain of diseases and to cure them. Thus, the story and the history of
drugs is as old as the mankind.
• In the early period, primitive man went in search of food and ate at random
plants or parts like tubers, fruits, leaves, etc.
• If he found that no harmful effects were observed, he considered them as edible
materials and used them as food.
• If he found that by their eating other actions were found, they were
considered inedible and according to the actions he used them in treating
symptoms or diseases.
• If it caused diarrhoea, it was used as purgative,
• if vomiting it was used as an emetic and
• if it was found poisonous and death was caused, he used it as an 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 from one generation to another generation and new
knowledge was added in the same way.

11. In India knowledge of medicinal plants is very old and medicinal properties of
plants are described in Rigveda and in Atharvaveda (3500- 1500 BC) from which
Ayurveda has developed.
In the ancient well-known treatises are Charka Samhita dealing mostly with plants
and Sushrut Samhita in which surgery is also mentioned.
In Egypt, people were familiar with medicinal properties of plants and animals.
They were familiar with human anatomy and knew of embalming the dead and
preserving their bodies as described in Papyrus Ebers (1550 BC), an ancient book
found in one of the mummies.
Greek scientists contributed much to the knowledge of natural history. Hippocrates
(460—370 BC) is referred to as father of medicine and is remembered for his
famous oath which is even now administered to doctors.
Aristotle (384—322 BC), a student of Plato was a philosopher and is known for his
writing on animal kingdom which is considered authoritative even in twentieth
century.

12. Egyptians (Ebers papyrus, 1550 BC)

13. Authors of antiquity
Hippocrates (460-377 BC)
“The Father of Medicine”

14. Dioscorides (40-80 AD)
“De Materia Medica” (600 medicinal
plants)

15. The Islamic era
Ibn Altabari (770 850)
” “

16. Theophrastus (370—287 BC) a student of Aristotle, wrote about plant
kingdom.
Dioscorides, a physician who lived in the first century AD, described
medicinal plants, some of which like belladonna, ergot, opium, colchicum
are used even today.
Pliny wrote 37 volumes of natural history and Galen (131—200 AD)
devised methods of preparation of plant and animal drugs, known as
'Galenical's' in his honour.
Pharmacy separated from medicine and materia medica, the science of
material medicines describing, collection, preparation and compounding,
emerged. As mentioned earlier in 1815 Seydler introduced the name
pharmacognosy.
Even up to the beginning of 20th century pharmacognosy was more a descriptive
subject akin mainly to botanical science and it consisted of identification of drugs
both in entire and powdered conditions and concerned with their history, commerce,
collection, preparation and storage.

17. Period 1934-1960
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 modem methods and techniques of
analytical chemistry, including paper, thin layer and gas chromatography and
spectrophotometry.
The substances from the plants were isolated, their sfructures elucidated and
pharmacological active constituents studied. The development was mainly due to
the following four events:
l. Isolation of penicillin in 1928 by William Fleming and large scale
production in 1941 by Florey and Chain.
2. Isolation of reserpine from Rauwolfia roots and confirming its hypo-
tensive and tranquilizing properties.

18. Difference between Organized and
Unorganized drugs

19. Examples of unorganized drugs

21. Dried juices

22. Dried extract
•Dried extract is a solid drug preparation that can be incorporated into tablets,
coated tablets and capsules. In production, the drug is most exhaustively extracted
with a solvent. Thereafter, the solvent used for extraction evaporates again and the
solid residue is fed to a drying process. Dried extracts have a moisture content of
max. 5%, however, they tend to attract moisture and thus clump together.
Therefore, the dried extracts often contain additives such as maltodextrin, syrup,
silica, etc..

23. Gums and mucilages

24. Oleoresins(resins and gums)

25. • Definition of oleo-gum-resin:
A solid plant exudation (as Asafoetida or myrrh) consisting of a mixture
of volatile oil, gum, and resin.

26. Classification of drugs

28. Classification of crude drugs
• Crude drug i.e Simple drug
• Crude drugs are plant, animal or their parts which after collection
are subjected only to drying or making them into transverse/
longitudinal slices pieces or peeling them in some cases. They
exist in natural form.
• Crude drugs may be derived from various natural sources like
plants, animals, minerals and micro- organisms etc.

29. • Because of their wide distribution the arrangement of
classification in a definite sequence is necessary to
understand easily. Although each system of
classification has its own merits and demerits, but for
the purpose of study the drugs are classified in the
following different ways:
Alphabetical classification
Morphological classification
Taxonomical classification
Pharmacological classification
Chemical classification
Chemo-taxonomical classification

30. 1. Alphabetical Classification
The crude drugs are arranged according to the alphabetical order/form of
their Latin and English names. Some of the Pharmacopoeias and
reference books which classify crude drugs according to this system are
as follows.
The time-tested alphabetical classification is now-a-days considered to
be the least disputed way of classification in all walks of life.
Pharmacopoeias have always been written on this basic mode of
classification. For drugs either Latin names or common vernacular
names can be used.

31. 1)Indian Pharmacopoeia (IP) 1955 (Latin)
2)Indian Pharmacopoeia (IP) 1966 (English)
3)British Pharmacopoeia (BP) (English)
4)British Pharmacopoeia Codex (BPC) (English)
5)United States of Pharmacopoeia (USP) (English)
6)European Pharmacopoeia (Latin)

32. Advantages:
• It is simple method, in this system location,
tracing and addition of the drug is easy,
• No technical person is required for handling the system.
Disadvantages:
• Scientific nature of the
by this method,
drug cannot be identified
whether they are organised or
unorganised drug.
• This system does not help in distinguishing the drugs of
animal and mineral source. (Original source is not clear)
plant,

33. • Examples:
• Acacia, Agar, Benzoin
,
Beeswax
,
Cinchona,
Cinnamon, Digitalis
,
Datura, Ephedra,
Jalap, Kino, Linseed,
Fennel,
Mustard,
Ginger, Isapagol,
Nutmeg, etc.

34. 2. Morphological classification
• Here the crude drugs are arranged (Grouped) according
to the of the plant or animal represented into organized
(Cellular) drugs and unorganized ( Acellular ) drugs.
Organised (Cellular):
•Drugs are the direct parts of the plant and are divided
into leaves, barks wood, root, rhizome, seed, fruit,
flower, stem, hair and fibers.

35. Unorganised ( Acellular):
Drugs are the products of plant, animal and mineral
source and they are divided into dried latex, dried juice,
dried extracts, gums, resins, fixed oils and fats, waxes,
volatile oil, animal products, minerals (Solids, liquids,
semi solids etc).

36. Plant parts
Leaves
Barks
Wood
Roots
Rhizomes
Flowers Seeds
Fruits Stems
Hair and Fibres
Drugs
Datura, Senna, Vasaka,
Digitalis, Cinnamon,
Cinchona, Kurchi,
Quassia, Sandalwood, Red
sanders
Rauwolfia, Liquorice, Ipecac
Ginger, Podophyllum,
Turmeric Clove, Saffron,
Pyrethrum
Nux vomica, Linseed,
Isapgol Fennel, Coriander, Dill
Ephedra
Organised drugs
(Plant)
(Cellular drugs)

37. Plant, animal, Mineral Drugs
Dried latex Opium, Papain
Dried Juice Aloe, Kino
Dried extracts Agar, Catechu, Pectin
Gums
Resins
Acacia, Tragacanth, Stericulia
Benzoin, Colophony, Asafoetida
Fixed oils and fats Castor , Chaulmoogra, Cotton seed
Waxes Beeswax, Spermaceti
Volatile oils Coriander, Cinnamon, Clove
Animal products Bees wax, Shark liver oil, Gelatin
Minerals Bentonite, Kaolin, Talc
Unorganised drugs
(Acellular drugs)

38. Advantages:
• This system of classification is more convenient for
practical study especially when the chemical nature of the
drug is not clearly understood.
• This type of classification is very useful in identifying the
adulterants used.
Disadvantages:
• It does not give an idea about biological source,
chemical constituents and uses.
•When different parts of the plant
contain different chemical constituents, it is difficult
to classify them.

39. 3. Chemical classifications of crude drugs
Here, the crude drugs are divided into different groups
according to the chemical nature of their most important
constituent present in the drug to which the
pharmacological/therapeutic activity of drug is attributed.

40. Chemical constituents Drugs
Alkaloids Glycosides
Tannins Volatile oil
Lipids
Carbohydrates and derived
products
Resins
Vitamins & hormones
Proteins & enzymes
Datura, Vasaka, Vinca, Lobelia
Cascara, Senna, Digitalis
Catechu, Myrobalan, Ashoka
Clove, Eucalyptus, Cinnamon
Castor oil, Beeswax, Arachis oil
Acacia, Agar, Honey, Linseed
Tragacanth, Starch
Colophony, Benjoin,
Yeast, Shark liver oil, Insulin
Gelatin, Papain,

41. Advantages :
• Chemical constituents are known,
• Medicinal uses are known
Disadvantages :
• Drugs of different origin are grouped under similar chemical
titles.
• This type
placement
chemicals.
of classification makes no proper
of drugs containing two different types of
• Eg: Certain drugs are found to contain alkaloids and
glycosides (Cinchona), Fixed oil and volatile oil (Nutmeg) of
equal importance together and hence it is difficult to
categorize them properly

42. 4. Taxonomical classification of crude
drugs
In this system the drug are arranged according to
taxonomical studies. The drugs are arranged according to
their phylum, order, family, genus and species. It is
purely a type of botanical classification or biological
classification and restricted mainly to crude drugs from
plant source.

43. Phylum
Angiosperms
(Monocotyledons)
Order
Liliflorae
Microspermae
Family
Liliaccae
Dioscoriaceae
Drugs
Colchicum, Asparagus
Dioscorea, Vanilla
Angiosperms
(Dicotyledons)
Papaverales Papaveraceae Opium
Rosales
Rutales
Rosales
Leguminaceae
Rutaceae
Almond, Rose oil
Glycyrihiza, Senna
Bael,Lemon, Orange
Rhamnales
Malvales
Umbelliflorae
Rhamnaceae
Malvaceae
Umbelliferae
Gentianales Loganiaceae
Gentianceae
Apocyanaceae
Cascara Cotton
Coriander,Caraway,
Fennel
Nuxvomica Chirata
Kurchi, Strophanthus

44. Advantages:
• Easy for the classification of crude drugs
Disadvantages:
• The system is criticized for its failure to recognize the
organised / unorganised nature of crude drugs in their
morphological studies.
• The system fails to face into an account chemical nature of
active constituent and therapeutic significance of crude drugs.
• The drugs obtained from plants having alternate leaves,
flowers, seeds, capsules (Hyocyamus, Datura, Bellodonna,
Stromonium) are considered with other members of solanaceae.

45. 5. Pharmacological classification of crude
drugs
The crude drugs are grouped according to
Pharmacological action (Therapeutic action) of their chief
active constituent (most important) or therapeutic uses.

46. • Bitter
• Carminatives
• Emetics
• Anti-amoebic
• Bulk Laxatives
• Purgatives
-
-
-
-
-
-
Quassia,Cinchona, Gentian
Dill, Clove,Fennel,Coriander
Ipecac
Kurchi, Ipecac Agar, Isapgol
Senna,Castor oil
• Expectorant
• Antitussive
• Bronchodilators
-
-
-
Liquorice, Vasaka, Ipecac
Opium Ephedra,Tea
• Cardio- tonics - Digitalis, Squill, Stropanthus

47. • Cardiac depressant
• Antihypertensive
-
-
Cinchona,Veratrum
Rauwolfia
• Central analgesics
• CNSstimulants
• CNSdepressants
•
•
•
•
•
Antispasmodics
Anticancer
Antirheumatics
Anthelmintics
Astringents
• Antimalarials
• Local anesthetics
-
-
-
-
-
-
-
-
-
-
Opium
Coffee
Opium
Bellodonna
Vinca, Podophyllum, Cochicum
Aconite, Guggul, Colchicum
Vidang, Quassia,Malefern
Catechu.
Cinchona,Artemisia.
Coca

48. Advantages
• The special advantage is that if even chemical constituents of
the crude drugs are not known they can be classified
properly on the basis of therapeutic or pharmacological uses.
Disadvantages
• Regardless of morphology, taxonomical status or chemical
nature, the drugs are grouped together, provided they exhibit
similar pharmacological uses.
• Eg: Senna, Castor oil, Jalap, Colocynth are grouped together
as purgatives/laxatives because of their common
pharmacological action.

49. 6. Chemo- taxonomical classification of
crude drugs
• In this system of classification, the equal importance is
given for taxonomical status and chemical constituents.
There are certain types of chemical constituents which
arecharacteristics of certain classes of plants.
•Eg:Tropane alkaloids generally occur in most of the
members of Solanaceae
•Eg: Volatile oils occur in the members of
Umbelliferae and Rutaceae.

52. Adulteration and
Evaluation of Crude
drugs

53. Objectives
On completion of this lesson, you would be
able to know:
• Methods of adulteration of Crude Drugs
• Commonly used substitutes in adulteration
• Evaluation for determining adulterants

54. Adulteration and Evaluation
• Adulteration involves incorporation of impurities.
• Includes spoilage deterioration admixture.
• Genuine drugs are intentionally substituted.
• With spurious, inferior, defective or harmful substances.

55. • Adulteration is a practice of substituting original crude drug partially or
wholly with other spurious substances but the later is either free from or
inferior in chemical and therapeutic properties.
• The motives for intentional adulteration are normally commercial one
and originate mainly with the intention 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. It is also very common with the contraband drugs.
• Adulteration means deterioration, admixture, sophistication, substitution,
inferiority and spoilage

61. • The ovoid tears of gum acacia, ribbon shaped characteristic of
tragacanth, disc-shaped structure of nux vomica, conical shape
of aconite, quills of cinnamon etc. are important diagnostic
characters.
• The general appearance of the lot of a crude drug often indicates
whether it is likely to comply with prescribed standards, such as
percentage of seed in colocynth, stalk in clove, etc.
• Over drying, makes leaf drugs and flowers brittle and cause
them to break in transit making the task of morphological
evaluation difficult.
• The wavy shape of Rauwolfia, pungent taste of capsicum and
ginger, brown colour of cinnamon, odour and taste of spice-
drugs like, asafoetida, black pepper, nutmeg, caraway, cummin,
etc. are important diagnostic organoleptic characteristics.

63. • Microscopic evaluation also covers study of the constituents by
application of chemical methods to small quantities of drugs in
powdered form or to histological sections of the drug (Microchemistry
or chemomicroscopy).
Examples:
• A drop of phoroglucinol and concentrated hydrochloric acid give red
stain with lignin.
• Mucilage is stained pink with ruthenium red and also, when treated with
corallin soda and few drops of sodium carbonate solution, cellulose
swells and dissolves in cuoxam,
• while N/50 iodine solution stains blue starch and hemicelluloses.
• Histological studies are made from very thin sections of drugs.
• The characteristics of cell walls, cell contents, starch grains, calcium
oxalate crystals, trichomes, fibres, vessels, etc. can be studied in detail
• e.g. lignified trichomes in nux vomica, warty trichomes of senna, wavy
medullary rays of cascara bark, glandular trichomes of mint etc. Some
important types of Trichomes are shown below.

64. • Microscopic linear measurements and quantitative microscopy are also
covered under this technique of evaluation.
• The powdered cloves do not contain sclereid or calcium oxalate crystals, but
both of them are present in powdered clove stalks.
• Powdered clove fruits show presence of starch while it is absent in cloves.
• Presence of non-lignified vessels in powders of rhubarb and ginger
indicate adulteration
• Other important histological aspect is the quantitative microscopy and linear
measurements. The various parameters studied here are stomata number and
index, palisade ratio, vein-islet number, size of starch grains, length of fibres,
ete.
• Senna varieties are distinguished by differing stomata number and palisade
ratio. The diameter of starch grains in Cinnamomum cassia is 10 microns;
hence, useful for detecting adulterants. The number of sclerenchymatous cells
per square mm of cardamom is useful for detecting different varieties of
cardamom seed.

72. There are six forms of calcium oxalate crystals in plants as follows:
1) Cubical (Prisms): As the name indicates, these crystals are cubical' in
shape (i.e. th . width and length is equal) and also have three equal
axes, all at right angles to one
2) Rhombic (Diamond Shaped): Here crystals have three axes, which
axes are at right to each other and unequal in length.
3) Tetragonal: This is characterized by presence of three axes, at right
angles to one vertical or principal axis.
4) Monoclinic: This form has three axes and all the three are unequal.
The lateral two at right angles to each other, while the third. i.e.
Principal is at right angles to lateral The monoclinic crystals shine
more than the tetragonal system.

74. 5) Acicular: These are excessively long slender forms, with pointed
ends and normally
6) Rosettes (Clusters): These are also aggregate crystals. This type has
shape similar to full expanded rose flower and hence the name
rosettes
Apart from above six types many times, very minute deltoid or arrow-
shaped crystals occupying the full cells in which they occur, are also
reported. They are known as Microsphenoidal or sandy crystals of
calcium oxalate.

76. M = weight in mg of the sample, calculated on basis of sample dried
at 1050 C P = 2,86,000 in case of ginger starch grains powder
Lycopodium spore method can be used for evaluation of powdered
clove, ginger, cardamom,nutmeg,umbelliferous fruits, etc.

80. Water immiscible solvent, such as light petroleum is used for the
extraction of fixed and essential oils, steroids and aglycones.
Chloroform and ether are used for the separation of alkaloids and
quinines.
The extraction of organic bases like alkaloids usually necessitates
basification of plant material if a water immiscible solvent is to be used
while for aromatic acids and phenols, acidification may be required.
The glycosides are soluble in water and alcohol, but insoluble in
non-polar solvents.
Tannins are phenolic matter soluble in water, alcohol and ethyl acetate.
Extraction itself may be performed by repeated maceration with
agitation, percolation or by continuous extraction using Soxhlet
extractor.

82. • Each extract is concentrated by distilling off the solvent and
then evaporating to dryness on water-bath.
• The extract obtained with each solvent is weighed. Its percentage
is calculated in terms of air-dried weight of plant material. The
colour and consistency of the extract are noted.
• The extracts with different solvents can also be prepared by
successively macerating (co extraction) the powdered drug in order
of increasing polarity.
• The general approach for extraction of different constituents from
fresh plant may be briefly described in the following chart

89. THANK YOU