1. Adulteration and Evaluation of Crude drugs

2. Recap In the last we have discussed about Methods of adulteration
Commonly used substitutes in adulteration
Evaluation for determining adulterants

3. Objectives On completion of this period, you would be able to know
Organoleptic evaluation
Microscopical evaluation
Physical evaluation
Chemical evaluation
Biological evaluation
Standards in pharmacopoeia

4. Evaluation of Crude Drugs
Evaluation refers to the Standardisation of crude drugs
It includes
Identity of the crude drug and determination of its
Quality and
Purity
Identity of the drug is confirmed by
Comparing the sample with an authentic sample or
Comparing with the Official Literature available

5. Evaluation of Crude Drugs
Quality
refers to the amount of Active chemical constituents
present in the crude drug
Purity
refers to the freedom from admixture

6. Organoleptic (Morphological) Evaluation:
It involves study of crude drugs by utilizing our organs of sense
Gross morphology and other sensory characters
like colour, size, shape, odour, taste, fracture, texture etc.,

7. Microscopical Evaluation
Study of microscopical characters of the organised drug
Types of cells, tissues present, cell contents like starch, calcium oxalate, mucilage, special structures like stomata or trichomes present or absent
Microchemical tests useful in evaluating certain organised drugs

8. Microscopical Evaluation
Quantitative microscopy
Stomatal number
Stomatal Index
Vein-islet number
Palisade Ratio

9. Physical Evaluation: Determination of typical physical constants
Viscosity
Swelling factor
Melting point
Specific gravity

10. Physical Evaluation: Refractive index Ash values Optical rotation
Volatile oil content of crude drugs
Moisture content

11. Foreign organic matter:
Pharmacopoeia prescribe maximum limit for
other parts of plants or other organic matter
in many crude drugs and also include
Animal excreta, Moulds or Insects

12. Extractive values
The chemical constituents may be extracted with suitable solvent known as extractives
Water soluble extractives : water soluble constituents
Alcohol soluble extractives: Alkaloids, Glycosides, etc.,
Ether soluble extractives
Volatile : Volatile oils
Non-volatile : Resins

13. Volatile oil content
Drugs containing volatile oil like Cinnamon, Clove etc., are evaluated by determining volatile oil content by Steam distillation

14. Ash values
Refer to the amount of inorganic matter present in the crude drug or collected along with the drug
Total Ash value
Acid Insoluble Ash
Water soluble Ash
Sulphated Ash

15. Chemical Evaluation:
It involves determination of Active chemical constituents
Assays
Total alkaloidal content
Assayed by acid base titrations
Non-aqueous titration.

16. Biological Evaluation:
Some crude drugs cannot be evaluated satisfactorily by Chemical or physical methods
They may be assayed by making use of
Living tissue or organs
Animals or
Micro-organisms like Bacteria or fungi

17. Biological Evaluation
Bacteria and fungus are used to determine
Anti-bacterial and Anti-fungal activity
For Biological assay of Vitamin – D
containing substances guinea pigs are used.
Bio-assay of digitalis is done on pigeons

18. Significance of Pharmacopoeial Standards
Drugs should be uniform in quality
Type of standards:
Structural standards
Analytical standards
Physical constants

19. Pharmacopoeia The important pharmacopoeias are
Pharmacopoeia is an official code Containing a list of established drugs
The important pharmacopoeias are
Indian Pharmacopoeia - I.P.
British Pharmacopoeia - B.P.
United States Pharmacopoeia- U.S.P.

20. Pharmacopoeial Standards
The authenticity of a crude drug is established
By references given in Pharmacopoeias.

21. Summary In this class we learnt about Organoleptic evaluation
Microscopical evaluation
Physical evaluation
Chemical evaluation
Biological evaluation
Standards in pharmacopoeia

22. Quiz
Confirmation of identity of crude drugs by studying microscopical characters comes under
Morphological evaluation
Physical evaluation
Biological evaluation
Microscopical evaluation

23. Frequently Asked Questions
What is evaluation?. List out various evaluation methods. (April 2006)
Define adulteration. Mention the various methods used in adulteration of drugs (April 2004)