EVALUATION OF CRUDE DRUGS FOR STANDARDIZATION

1. EVALUATION
PARAMETERS FOR
CRUDE DRUG
Presentation by-
DR. PANKAJ NAINWAL

2. Question arises:
Why there is need for evaluation of crude drug?
To confirm the identity and
determining the quality crude drug
by seeking the presence of
adulterants mixed with it used for
Degradation of quality which can
be achieved by-
Defective Collection of species
Intentional adulteration
Deficient preparation of drug
Inaccurate Storage of crude drug

3. Methods of evaluation of crude drugs
Basically five methods are used for evaluating
crude drugs.
The evaluation can be done in these methods
quantitatively and qualitatively both. The
methods are:
1. Organoleptic evaluation
2.Microscopical Evaluation
3.Physical evaluation
4.Chemical Evaluation
5.Biological Evaluation

4. Organoleptic Evaluation

5. Sensory Evaluation:
Based on evaluating colour, odour, taste, texture, fractures etc
Organoleptic Evaluation
Texture and Fracture: Texture means touch, either smooth or rough, and
fracture given to bark part, which reveal it is powdered, fibrous, tindles etc
Colour: The crude drugs was kept in day light and was checked with the standard
crude drug or processed drug.
Odour: To achieve odour from the drug it can directly smell or pressed to ooze the
Odorous material having distinct odour. The strenght of odour (None, Weak,
Strong) and its sensation ( aromatic, fruity, muddy, rancid) was checked.
Taste: To achieve taste one must sense it after bring it into mouth. Some e.g are:
Bitter taste: Almond, Gentian, Picorrhizia
Sweet Taste: Liquorice, Honey
Mucilagenous: Linseed, Isabgol
Acrid: Jalap, Kaladana
Sour: Lemon

6. Organoleptic Evaluation
Qualitative evaluation can be done by two ways
Morphological Evaluation:
Based on evaluating the SIZE, SHAPE of crude drugs
SIZE: A millimeter scale is used for the measurement of length,
breadth and height of the crude drug.
SHAPE: a) Leaf: Simple, Compound
b) Shape of lamina: Acicular, linear, lanceolate ovate etc
c) Flower: Campanulate, Racemose, actinomorphic etc
d) Fruit: Globular, oblong etc
e) Seed: Oval, Reniform, Planoconvex etc
f) Bark: Flat, Cured, Channelled, quill, double quill

8. Shapes of Fruits

9. MICROSCOPICAL
EVALUATION

10. 1. BY CUTTING THIN SECTION OF VARIOUS PART OF DRUGS
T.S of Leaf T.S of Root
T.S of Seed

11. 2. Quantitative Microscopy
Methods are:
1. Stomatal number
2. Stomal index
3. Vein- islet number
4. Vein- termination number
5. Palisade ratio
6. Lycopodium spore method

12. Stomatal number:
It is defined as average no. of stomata present in per square mm. of
epidermis of leaf.
S. No. Species Upper surface Lower surface Ratio
Range Mean Range Mean Upper/ Lower
1 Datura stramonium 58-141 88 144-224 199 2.26
2 Datura tatula 91-173 124 155-331 208 1.68
3 Datura innoxa 82-172 141 105-223 165 1.77
Example of some plant species:

13. Types of stomata:
Stomata is dived into four types
1. Moss type
2. Graminae type
3. Gymnosperm type
4. Dicotyledonous type
Out of this Dicotyledonous type is of various types based
On arrangement of subsidiary cells.
Electron microscopic photo of Stoma

14. Diacytic stoma:
A stoma with two subsidiary cells, in which cross walls
are transverse (right angle) to the long axis of the stoma.
Stomata
Subsidiary
cells

15. Paracytic stomata:
A stomatal complex in which one or more of the
subsidiary cells that flank the stoma are parallel with the
long axis of the guard cells.
Stomata

16. Anisocytic stomata: The subsidiary cells of the guard cell
pair, in which the three surrounding subsidiary cells are of
unequal size.
1
3 2

17. Anomocytic stomata: Stoma surrounded by four or
more subsidiary cell irregular in shape

18. Stomatal index:
This is expressed as:
(Number of stomata per mm2 × 100)
(Number of stomata + Number of epidermal cells per mm2).
This value has been found useful in comparing leaves of
different sizes. This is constant for every leaves.
S. No. Species Stomatal index
Upper surface Lower surface
1 Cassia senna 11.4 – 13.3 10.8- 12.6
2 Atropa belladonna 2.3 – 3.9 20.2 – 23.0
3 Datura metel 18.1 – 18.7 24.5 – 25.3
4 Digitalis pupeura 1.6 – 4.0 17.9 – 19.5

19. Palisade ratio:
Palisade ratio is defined as the average number of palisade cell
Beneath each epidermal cell of leaf.
S. No. Species Palisade Ratio
1 Atropa belladona 6-11
2 Solanum nigrum 2-4
3 Digitalis purpurea 3.7-4.2

20. Vein-islet number:
It is number of vein-islet present in per square of mm of leaf surface
Midway between midrib & margin.
Vein-termination number:
It is number of vein-termination present in per square of mm of
leaf surface Midway between midrib & margin.
S. No. Species Vein-islet number Vein-termination number
1 Senna 19.5 – 22.5 24.2 – 31.4
2 E.coca 9 – 12 16.8 – 21.0
3 Digitalis pupeura 2- 5.5 2.5 – 4.3

21. It is a method for the study of powdered drugs having well
defined particles like pollens, starch grains, single layered tissues
or some other types of uniformly thick particles. It is used when
chemical and other methods of evaluation of crude drugs fail as
accurate measures of quality. On average 94000 spores per mg of
powdered lycopodium are present.
N×W×94,000× 100 = % purity of drug
S×M×P
N= no. of characteristic structure in 26 fields
W= wt in mg of lycopodium taken
S= no. of lycopodium spores in same 25 field
M= wt in mg of sample calculated on material dried at 1050C
P= 2,86,000 spores in case of ginger starch grains
Lycopodium Spore Method

22. PHYSICAL METHOD
OF
EVALUATION

23. 1
Solubility,
Melting
Point
Optical
Rotation and
Refractive
index
Foreign
Particle
Extractive
Values
Ash Values
Moisture
Content
Volatile
content/
Distillatio
n
PHYSICAL
EVALUATION
Chromatography
&
Spectroscopy

31. Chemical
Evaluation

33. Chemical Evaluation
This evaluation reveals with
screening of phytoconstituents
present in crude drug.
It include chemicl test for every
constituent.

34. 1
Protiens &
Amino
acids
•Biurete test
•Ninhydrin
test
Test for
Saponins
•. Foam test
•Hemolytic tst
Test for
Phytosterols
•Libermann ‘s test
•Salkovaski test
Test for
Alkaloids
•Mayer’s
•Wagner’s
•Dragondroff’s
•Goldbeater’s
skin
•Phenazone
•Catechin
Test for
Glycoside
•Brontrager’s
•Legal
•Baljet
Chemical
Evaluation
Test for
Carbohydrates
•Molish Test
•Fehling Test
Test for
Tannins
Test for
Flavonoids
Shinoda Test

36. Analgesic
activity
Anti-ulcer
activity
Diuretic
activity
Anticancer
activity
Antidiabetic
activity

37. COMMON TREATMENT METHODS:
Animal used: Rats/ Mices/ Guinea Pigs
Dose required: As per OECD guidelines
Standard Dose: As per Literature available to show desired
activity.
Treatment:
1. Control (No drug, Saline water, Distill water)
2. Extracts (Plant Extract or Isolated components
after column)
3. Standard (Marketed preparation used for activity)