Introduction and scope of pharmacognosy by Dr.U.Srinivasa, Professor, Srinivas college of pharmacy, Mangalore

Useful for the first year b.pharma students

1. IN
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2. DEFINITION :
Pharmacy is the science of drug
making / deals with their procurement
(bring about), testing, storage and
conversion into suitable forms ( tablets,
capsules, emulsions etc)

3. DRUG :
Any substance used in the treatment of
disease or diagnosis is known as drug .
Diagnosis is the determination of nature
of disease.

4. CRUDE DRUG
It is the simple drug ,crude drugs are
plant, animal and their parts which after
collection are subjected only to drying or
making them into transverse or
longitudinal pieces or peeling (stripping
off skin or bark).They exist in natural
forms.

5. SOUCES OF DRUG
Drugs used in medicine may be organic and inorganic in
nature. Organic drugs are essentially of 2 types .
1. Purely synthetic : The product of man ‘s creation of new
chemical entities ( structures) non – existent before the
era of synthetic chemistry.
2.Drugs of biological origin : Produced in the living
cell, biogenic drugs (crude drugs)

6. PHARMACOGNOSY
Pharmacognosy is the science of drugs of biological origin
( plant, animal, mineral) or
The word pharmacognosy was coined in 1815
by a German Scientist SEYDLER has been derived from
two Greek words , Pharmacon ---- ‘ a drug, gignosco – ‘
acquire the knowledge of

7. Pharmacognosy is the subject of crude drugs
obtained from the plants (vegetable), animal and
mineral origin. Or It can also defined as the
objective study of crude drugs of the natural
sources processed scientifically.

8. The pharmacognosy is broadly defined as the
scientific and systematic study of the structural,
physical, chemical and sensory characters of crude
drugs of vegetable, animal and mineral origin along
with their history, method of cultivation, collection
and preparation for the market.

9. Recently it includes:
1- Modern isolation techniques.
2- Pharmacological testing procedures to prepare
purified substances.
3- Cultivation and propagation by tissue culture

10. SCOPE OF PHARMACOGNOSY
•Pharmacognosy has broad scope in the field of pharmacy
such as :
•1. ISOLATION OR ANALYSIS OF PHYTOCHEMICAL :
•Eg ; Strong acting substances such as glycosides from
digitalis leaves,
• Alkaloids from the plants of Belladonna, Hyocyamus,
Rauwlofia
•Morphine and other alkaloids from the plant opium were
isolated and clinical uses studied

11. 2. STRUCTURE ACTIVITY RELATIONSHIP :
Eg : Tubocurarine and Toxiferine from curare plant have
muscle relaxant properties because of quaternary
ammonium groups.
The hypotensive and tranquillizing actions of
reserpine are due to the trimethoxy benzoic acid

12. 3. DRUGS OBTAIN:ED BY PARTIAL SYNTHESIS OF NATURAL
PRODUCTS:
Eg : Preparation of Steroid hormones from diosgenin by
acetolysis and oxidation and further preparation of
cortisone by microbial reactions.
4. NATURAL PRODUCTS AS MODELS FOR SYNTHESIS OF NEW
DRUGS :
Eg: Morphine is the model of a large group of potent
drugs .
Cocaine for local anaesthetics
Atropine for certain spasmolytics

13. •5. DRUGS OF DIRECT THERAPEUTIC USES :
• Among the natural constituents which even now cannot
be replaced are important group of antibiotics, steroids,
ergot alkaloids, vincristine etc
•6. BIOSYNTHETIC PATHWAYS INVESTIGATION :
•Biosynthetic pathways are of primary and secondary
metabolites.
•Some of the important pathways are Clavin ‘s cycle of
photosynthesis,
•Shikimic acid pathway of aromatic compounds

14. •Acetate hypothesis for antharacene glycosides
•Isoprenoid hypothesis for terpens
•7.CULTIVATION AND COLLECTION OF MEDICINAL
PLANTS :
• clove, cinchona , cinnamon, senna, opium, etc
•8. PREPARATION OF HERBAL FORMULATIONS :
• churnas, asvas, aristas, leha, etc
•9. DEVELOPMENT OF TISSUE CULTURED PLANTS

15. Physical parameters
1.Mosture content
2.Ash values
3.Swelling factor
4.Extractive values
5.Melting point
6.Solubility
7.Optical rotation
8.Viscosity

16. ASH VALUES
The residue remaining after incineration is the
ash content of the drug.( inorganic salts of
carbonates, phosphates, silicates of sodium,
potassium, calcium and magnesium) is
known as ash content.
Ash value is a criterion to judge the identity OR
purity of the crude drug

17. TYPES OF ASH VALUES
1.Total ash value
2.Acid insoluble ash value
3.Sulphated ash value
4. Water soluble ash value

18. Total ash value:
Useful for detecting low grade products
Useful for detecting exhausted products
Useful for detecting excess of sandy
Useful for detecting earthy matter with
drug

19. DETERMINATION
1.Weigh accurately about 3gms of the powdered drug in a
tared silica crucible
2.Incinerate the powdered drug by gradually increasing the
heat until free from carbon and cool. Keep it in
desiccators
3. Weigh the ash and calculate the % of the total ash with
reference to the air dried sample

20. Acid insoluble ash value :
1. Used for the determination of earthy matter present on
roots, rhizomes, and also on the leaves
2. Crude drugs contain calcium oxalate crystals the amount
may varies depending on the environmental conditions

21. DETERMINATION
1. Boil the total ash obtained as above for 5 minutes with
25ml of dilute HCL
2.Filter and collect the insoluble matter on the ashless filter
paper , wash the filter paper with hot water, ignite in
tared crucible, cool and kept in desiccators
3.Weigh the residue and calculate the acid insoluble ash of
the drug

22. Sulphated ash value :
Used for the detection of low grade products
Water soluble ash value :
Used to detect either material exhausted by water or not
( Tea leaves, Ginger rhizomes)

23. SWELLING FACTOR
Significances :
Useful in the evaluation of crude drugs containing
mucilage
Useful for the detection of purity of the crude drug

24. DETERMINATION
1. Transfer 1 gm of the seeds to a 25ml
stoppered cylinder
2. Fill up to the 20ml mark on the cylinder with
water. Agitate gently and occasionally during
24 hours and allowed to stand
3.Measure the volume occupied by the swollen
seeds

25. EXTRACTIVE VALUES
Significances :
1.Useful for the evaluation especially when the
constituents of the drugs can not be readily estimated
by any other means
2.It also helps to indicate the nature of chemical
constituents present in the drug
3. Also helps in the identification of adulterants

26. TYPES
1.Water soluble extractive values
2.Alcohal soluble extractive values
3.Ether soluble extractive values

27. 1.Water soluble extractive value is applied for
the drugs which contain water soluble
constituents such as tannins, sugars, plant
acids and mucilage.
2.Alcohol soluble extractive value is applied
for the drugs which contain alcohol soluble
constituents such as tannins, resins and
alkaloids
Official method for the assay of myrrh &
asafoetida

28. 3.Ether soluble extractive value is applied
for the extraction of volatile oils, fixed oils
and resins.
1.Volatile ether soluble extractive value
2.Non volatile ether soluble extractive value

29. DETERMINATION
Water soluble extractive value:
1. Macerate about 5gm of the accurately weighed coarse powder
with 100ml of chloroform water in a 100ml volumetric flask for
24 hours .
2. Shake frequently for first 6 hours
3. Filter rapidly through filter paper and evaporate 25ml of water
extract to dryness in a tared flat-bottomed shallow dish.

30. 4. Dry the residue at 105 and weigh. Keep it in a
desiccators
5. Dry the extract to constant weight ,finally , calculate
the % W/W of Water soluble extractive value with
reference to the air dried drug.

31. •Alcohol soluble extractive values
•Macerate about 5gm of the accurately weighed coarse
powder with 100ml of 90% alcohol in a 100ml stoppered
flask for 24 hours .
•Shake frequently for first 6 hours
•Filter rapidly through filter paper and collect the filtrate
evaporate 25ml of alcohol extract to dryness in a tared flat-
bottomed shallow dish.

32. •Dry the residue at 105 and weigh. Keep it in a
desiccators
•Dry the extract to constant weight ,finally , calculate
the % w/w of alcohol soluble extractive value with
reference to the air dried drug.

34. SIGNIFICANCE:
1.The method is generally used when standardization is not
done satisfactory by chemical or physical methods
2.When the quantity of the drug /sample are very less then
the drugs are evaluated by biological methods

35. These methods are performed on living animals,
isolating living organ and tissue, animal preparation, and
micro-organism
( Bioassay)

36. Following method is used as
1.Anti inflammatory activity
2.Analgesic activity
3.Antipyretic activity
4.Anti ulcer activity
5.Antidiabetic activity
6.Anthelmintic activity on earth worms

37. 7.Cardiac activity- on frog and pigeon
8.Microbiological methods- living bacteria, yeast, molds are
used for the assaying vitamins and to determine the
activity of antibiotic drugs