Transcript Adulteration and Evaluation of Crude drugs

Adulteration and Evaluation of
Crude drugs
Recap
In the last we have discussed about
• Methods of adulteration
• Commonly used substitutes in adulteration
• Evaluation for determining adulterants
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
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
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
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.,
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
Microscopical Evaluation
Quantitative microscopy
Stomatal number
Stomatal Index
Vein-islet number
Palisade Ratio
Physical Evaluation:
Determination of typical physical constants
• Viscosity
• Swelling factor
• Melting point
• Specific gravity
Physical Evaluation:
• Refractive index
• Ash values
• Optical rotation
• Volatile oil content of crude drugs
• Moisture content
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
Extractive values
The chemical constituents may be extracted with suitable
solvent known as extractives
1.
Water soluble extractives : water soluble constituents
2.
Alcohol soluble extractives: Alkaloids, Glycosides, etc.,
3.
Ether soluble extractives
Volatile
: Volatile oils
Non-volatile
: Resins
Volatile oil content
• Drugs containing volatile oil like Cinnamon, Clove etc.,
are evaluated by determining volatile oil content by
Steam distillation
Ash values
•
Refer to the amount of inorganic matter present
in the crude drug or collected along with the drug
1. Total Ash value
2. Acid Insoluble Ash
3. Water soluble Ash
4. Sulphated Ash
Chemical Evaluation:
It involves determination of Active chemical
constituents
• Assays
• Total alkaloidal content
• Assayed by acid base titrations
• Non-aqueous titration.
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
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
Significance of Pharmacopoeial Standards
• Drugs should be uniform in quality
Type of standards:
• Structural standards
• Analytical standards
• Physical constants
Pharmacopoeia
• 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.
Pharmacopoeial Standards
• The authenticity of a crude drug is established
• By references given in Pharmacopoeias.
Summary
In this class we learnt about
• Organoleptic evaluation
• Microscopical evaluation
• Physical evaluation
• Chemical evaluation
• Biological evaluation
• Standards in pharmacopoeia
Quiz
1.
Confirmation of identity of crude drugs by studying
microscopical characters comes under
a.
Morphological evaluation
b.
Physical evaluation
c.
Biological evaluation
d.
Microscopical evaluation
Frequently Asked Questions
1. What is evaluation?. List out various evaluation
methods. (April 2006)
2. Define adulteration. Mention the various methods used
in adulteration of drugs (April 2004)