Evaluation /Quality Control / assessment of crude drug

 according to WHO guidelines 

(Part-I)

(S.Y. B. Pharm Unit -IV ) Unit -I


(T.Y. B. Pharm Sem -VI ) -Unit - IV


(Final Yr. B. Pharm) Section -II

As per PCI Syllabus 
Definition of Crude drug

Crude drugs are plant, animal or their parts which after collection are subjected to only drying or making them in to transverse/ longitudinal slices piece or peeling them in some cases. 
Crude drug occurrence

Crude drug are generally obtained by plant, animal and mineral origin.
1. Plant origin: whole plant or part of plant like leaves flowers, seeds and barks. or vegetable saps, extracts and secretions.
2. Animal origin: whole animals, glands or organs, extracts and secretions.
3. Mineral origin: ferrous sulfate, magnesium, zinc, gold etc


Definition of drug evaluation:

Drug evaluation may be defined as the determination of identity, purity and quality of a drug.
Identity: identification of biological source of the drug.
Quality: the quantity of the active constituents present.

Purity: the extent of foreign organic material present in a crude drug. 

Importance of evaluation of crude drugs

Determination of Biochemical variation in the drugs. Identification of deterioration due treatment and storage.
Reporting Substitution and adulteration, as result of carelessness, ignorance and fraud.

METHODS OF DRUG EVALUATION 
The evaluation of a drug is done by following methods.
1. Organoleptic evaluation
2. Morphological evaluation
3. Microscopic evaluation
4. Physical evaluation
5. Chemical evaluation
6. Analytical evaluation
7. Biological evaluation

Organoleptic evaluation

OR

Morphological evaluation

ORGANOLEPTIC EVALUATION

This refers to drug evaluation by means of organs of sense and includes other sensory organs like color, odour, taste, Size, shape and texture.
It includes the study of morphology and other sensory characters.
A) Odour 
i. Distinct
ii. Indistinct
iii. aromatic

B) Taste

i. Acidic (sour)
ii. Saccharine (sweet): indicates sugar or sugar like subs. e.g., liquorice.
iii. Saline (salty)
iv. Alkaline
v. Bitter: indicates presence of substances such as bitter principle e.g., glycoside, alkaloids.
vi. Tasteless

vii. Distinctive sensations to the tongue:
q   Mucilaginous and oily (soft feeling) e.g., linseed.
q    Astringent indicates presence of tannin.
q    Pungent (warm biting sensation) e.g., ginger.
q    Acrid (irritant sensation) e.g., Aconite, coca.
q    Nauseous (those tending to excite vomiting) e. g. Ipecac.

C) Colour

1. White: e.g., starch.
ii. Pale yellow: e.g., ginger, quill, white pepper.
iii. Deep yellow: e.g., peeled liquorice.
iv. Light pale brown: e. g., nux-vomica, fennel.
v. Dark brown: e.g., cloves bud.
vi. Dark reddish brown: cinchona.
vii. Red: (brick red): e.g., cinnamon bark inner portion.
viii. Pale green: e.g., lobelia.
ix. Greenish brown: most of the leaf herbs.

MORPHOLOGICAL EVALUATION 
Study of morphology includes visual examination of drug like study of shape & size of various parts of crude drug.

A)Flower : Floral parts: Stigmas,
B)corollas, anther, ovary, and receptacle.


B) Leaves and leaflet:

Length, width, apex, margin, venation, the texture of the leaf and the hairs in upper and lower surface.
The feel of the surface described as soft, hairy smooth.


C) Bark:
The barks occur in three shapes.
•Flat or curved pieces.
•Single quill.
•Double quills.
Barks have two surfaces,an Outer & inner.
 The inner surface is usually lighter in Colour, than the outer surface.


ROOTS AND RHIZOME DRUGS

A general scheme of examination of subterranean parts includes the size, shape, colour, surface, direction of growth, fracture, transverse surface, fractured surface, odour and taste, food reserves, chemical tests and special features etc.



FRUIT DRUGS
A general method of macroscopical examination of fruit drugs includes