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About Authors:
Dhiren Shah*1, Jatin Patel, Krunal Parikh
Seth G.L. Bihani S.D. College of Technical Education, R.U.H.S.
Sri Ganganagar, Rajasthan, INDIA

Abstract :
Involved Evaluation and Standardization techniques for crude drugs, mono or Polyherbal Frormulation. They involved the macroscopic techniques, microscopic techniques, physical evaluation and biological evaluation. They also involved the Quantitative analysis of Organophosphorus insecticides, Organochlorine and pyrethroid insecticides, microbial content determination.

Reference Id: PHARMATUTOR-ART-1506

Evaluation of drug means confirmation of its identity and determination of its quality and purity and detection of nature of adulteration.

IDENTITY: refer to exact authentic biological source of the drug can be established by actual collection of the drug from a plant or animal which has been identified or comparing a representative unknown sample with a published description of the drug with authentic drug sample.

QUALITY: refer to the intrinsic value of drug i.e. the concentration or amount of medicinal principles or active constituents present. These constituents are classified as non-living cell inclusion and have been studied under the heading, the chemical classification. This includes fixed oils, carbohydrates, glycoside, alkaloids, resin, fats or waxes, volatile oil, tannins, vitamins, alergens, etc. A high grade of quality in a drug is of prime importance. An effort should be made to obtain mainly this high quality.

The high grade quality of the drug be accomplished by:
1)  Collection of the drug from the correct natural source at proper time and in the proper manner.
2) Preparation  of the collected drug by proper cleaning, drying, garbling.
3) Proper preservation of the cleaned, dried pure drug against contamination through moisture, fungi, filth and insects.

PURITY: of the drug depends upon the absence of foreign matters whether organic or inorganic.

The crude drugs can be identified on the basis of their morphological, histological, chemical, physical, and biological studies.

The evaluation of crude drug is necessary because of three reason:
1. Biochemical variation in the drug
2. Deterioration due to treatment and storage
3. Substitution and adulteration, as a result of carelessness, ignorance or fraud

The different techniques involved in standardization of crude drugs are as follows:

· Organoleptic evaluation
· Microscopic evaluation
· Physical evaluation
· Biological evalution

Standardization of herbal drugs is not an easy task as numerous factors influence the bio efficacy and reproducible therapeutic effect. In order to obtain quality oriented herbal products, care should be taken right from the proper identification of plants, season and area of collection and their extraction and purification process and rationalizing the combination in case of polyherbal drugs.

Organoleptic evaluation
Organoleptic (Lit. “Impression on the organs”) evaluation of crude drugs refers to the evaluation of a drug by colour, odour, taste, size and shape, occasionally the sound or snap of fracture and special fetures including touch, texture, etc..

Organoleptic evaluation is also called MORHOLOGICAL or MACROSCOPICAL evaluation.

It is a technique of qualitative evaluation based on study of morphological and sensory profiles of whole drugs. Organoleptic evaluation means conclusions drawn from studies resulted due to impression on organ of senses.

PARAMETERS used for this type of evaluation can be explained as follows.

The colour is used in indicating the general origin of drug. e.g. material derived from the aerial part of the plant is usually green and the underground plat material is usually devoid of green colour.

The length, width and thickess of the crude material are of great importance while evaluating a crude drug.
A graduated ruler in millimetres is adequate for the measurement of the length, width and thickness of crude maerials small seeds and fruits may be measured by aligning 10 of them on a sheet of calibrated paper, with 1mm spacing b/w lines and dividing the result by 10.


To an  expert, odour and taste of crude material are extremely sensitive criteria based on individuals perception. Therefore, he description of this feature may sometime cause some difficulties.
·         Indistinct
·         Distinct
*      Aromatic
*      Balsamic
*      Spicy
*      Fruity
*      Mouldy or musty
*      Rancid
·         Weak
·         Strong

PROCEDURE: If the material is expected to be innocuous, place a small portion of the sample in the palm of the hand or a beaker of suitable size, and slowly and repeatedly inhale the air over the material. If no odour is perceptible, crush the sample between the thumb and index finger or between the palms of the hands using gentle pressure. If the material is known to be dangerous, crush by mechanical means and then pure a small quantity  of boiling water onto the crushed sample in a beaker. First determine the strebgth of the odour (none, weak, distinct, strong) and then the odour sensation (aromatic, fruity, musty, mouldy, rancid, etc.) A direct comparision of the odour with a defined substance is advisable (e.g. peppermint should have an odour similar t menthol, cloes an odour similar to eugenol)

Tastes are f tw types
·         True taste

*     Acid (S*ur)
*     Saline (Salty)
*     Saccharine (Sweet)
*     Bitter
*     Alkaline
*     Metallic

·         False taste (Sensati*ns t* the t*ngue)
*    Mucilagin*us (s*ft slimy feeling)
*    *il (Bland sm**th feeling)
*    Astringent (C*ntracti*n *f m*uth tissue)
*    Pungent (Warm biting sensati*n)
*    Acrid (Unpleasant, Irritating)
*    Nause*us (Induce v*miting)

Examine the untreated sample. If necessary, a magnifying lens (6x to 10x) may be used. Wetting with water or reagents, as required, may be necessary to observed the characteristics of a cut surface. The texture is best examined by taking a small quantity of material and rubbing it between the thumb and forefinger, it is usually described as ‘smooth’, ‘rough’,’guity’. Touch the material to determine if it is soft or hard, bend and rupture it to obtain information on brittleness and the appearance f the fracture plane whether it is fibrous, smooth, rough, granular, etc.

All this characteristics aare valuable in Indicating the general type of material and the presence of more then one component.

For convenience te description of macroscopic characters may be divided into four headings as-
a) Shape and size
b) Colour and external marking
c) Fracture and internal colour
d) Odour and taste

In some official crude drugs monograhs the entire macroscopic description consists of an organoleptic evaluation and is only means of evaluation given macroscopy refers to visual  appearance to baked eyes. The macroscopic study depends on the part of the plant from which the drug is obtained.

According to the plant part used all organized drugs can be classified into following groups.
A) Underground plant parts
B) Barks
C) Woods
D) Leaves
E) Flower fruit


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