This document discusses drug adulteration and evaluation. It defines different types of drug adulteration including unintentional adulteration due to confusion or lack of knowledge, as well as intentional adulteration such as substitution using inferior varieties or artificially manufactured substances. Evaluation of crude drugs involves assessing physical, chemical, and biological characteristics including organoleptic properties, microscopic and chemical analysis, and determining bioactivity and toxicity. Proper evaluation ensures the identity, quality and safety of crude drugs.

1. (
Gayatri Patra
Asst.professor
EPCP, Bangalore
Drug
Adulteration
and
Evaluation

2. Drug Adulteration
The term adulteration is defined as substituting original crude drug partially or wholly with other similar-
looking substances. The substance, which is mixed, is free from or inferior in chemical and therapeutic
property.
Inferiority is a natural substandard condition (e.g. where a crop is taken whose natural constituent is below the
minimum standard for that particular drug) which can be avoided by more careful selection of the plant
material.
Spoilage is a substandard condition produced by microbial or other pest infestation, which makes a product
unfit for consumption, which can be avoided by careful attention to the drying and storage conditions.
Deterioration is an impairment of the quality or value of an article due to destruction or abstraction of valuable
constituents by bad treatment or to the deliberate extraction of the constituents and the sale of the residue as the
original drugs.

3. • Admixture is the addition of one article to another through accident,
ignorance or carelessness.
• Sophistication is the deliberate addition of spurious or inferior material
with intent to defraud ; such materials are carefully produced and may
appear at first sight to be genuine.
• Substitution is the addition of an entirely different article in place of that
which is required.

4. Types of Adulterants
Unintentional adulteration may be due to the following reasons:
1. confusion in vernacular names between indigenous systems of medicine and local dialects
2. lack of knowledge about the authentic plant
3. nonavailability of the authentic plant
4. similarity in morphology and or aroma
5. careless collection
6. other unknown reasons

5. Intentional Adulteration
Intentional adulteration may be due to the following reasons:
Substitution using inferior commercial varieties
Substitution of superficially similar inferior natural substances
Substitution with artificially manufactured substances
Substitution with exhausted drugs
Adulteration using the vegetative part of the same plant
Addition of toxic materials
Adulteration of powders
Addition of synthetic principles

6. Substitution using inferior commercial varieties
In this type, the original drugs are substituted using inferior quality drugs that may be similar in
morphological characters, chemical constituents or therapeutic activity.
For example, hog gum or hog tragacanth for tragacanth gum, mangosteen fruits for bale fruits,
Arabian senna, obovate senna and Provence senna are used to adulterate senna, ginger being
adulterated with Cochin, African and Japanese ginger.
Japanese ginger Zingiber officinale

7. Substitution of superficially similar inferior natural substances
The substituents used may be morphologically similar but will not be having any relation to the genuine article
in their constituents or therapeutic activity.
E.g. Ailanthus leaves are substituted for belladonna, senna, etc. saffron admixed with safflower; clove stalks and
mother cloves with cloves; peach kernel oil used for olive oil and Japan wax for beeswax are few examples for
this type of adulteration.
Saffron safflower Japan wax beeswax

8. Substitution with artificially manufactured substances
To provide the general form and appearance of various drugs, some materials are artificially manufactured and
are used as substitute of the original one.
E.g. Compressed chicory in place of coffee, paraffin wax after yellow coloration substituted for bees wax, bass
wood in place of Nutmeg.
Compressed chicory Coffee Bass wood Nutmeg

9. Substitution with exhausted drugs
• Here the same plant material is mixed which is having no active medicinal components as they
have already been extracted out. This practice is most common in case of volatile oil containing
materials like clove, fennel, coriander etc.

10. Adulteration using the vegetative part of the same plant
• The presence of vegetative parts of the same plant with the drug in excessive amount is also an
adulteration. For example, the lower plants like mosses, liverworts and epiphytes growing on bark
portion are mixed with cascara or cinchona. Excessive number of stems in drugs like lobelia,
stramonium, etc. are few examples for this type of adulteration.
• liverworts epiphytes

11. Addition of toxic materials
• In this type of adulteration, the materials used for adulteration would be toxic in nature. A big mass
of stone was found in the centre of a bale of liquorice root. Limestone pieces with asafoetida, lead
shot in opium, amber-coloured glass pieces in colophony, barium sulphate to silver grain cochineal
and manganese dioxide to black grain cochineal, are few examples in this adulteration.
silver grain black grain colophony

12. Adulteration of powders
• Powdered drugs are found to be adulterated very frequently. Adulterants used are generally powdered waste
products of a suitable colour and density. Powdered olive stones for powdered gentian, liquorice or pepper;
brick powder for barks; red sanders wood to chillies; dextrin for powdered ipecacuanha, are few adulterants.
• olive stones gentian red sanders wood

13. Addition of synthetic principles
• Synthetic pharmaceutical principles are used for market and therapeutic value. Citral is added to
lemon oil, whereas benzyl benzoate is added to balsam of Peru.

14. Evaluation of crude drugs
• The evaluation of crude drugs involves the assessment of the physical, chemical, and biological
characteristics of plant, animal, or mineral substances before they are further processed into
pharmaceuticals or herbal remedies. Here are some key aspects of the evaluation process:
Organoleptic Evaluation:
Color: Check for the color of the crude drug, as it can indicate the presence of specific compounds.
Odor: Assess the characteristic smell of the material.
Taste: Evaluate the taste, if applicable.
Macroscopic Evaluation:
Size and Shape: Examine the size and shape of the crude drug.
Texture: Assess the texture, noting any peculiarities or irregularities.
Foreign Matter: Look for any foreign materials like dirt, stones, or other impurities.

15. Microscopic Evaluation:
Cellular Structure: Examine the cellular structures using a microscope to identify plant tissues or other
components.
Starch Grains, Trichomes, etc.: Identify specific microscopic features that are characteristic of the plant or
substance.
Chemical Evaluation:
Chemical Constituents: Determine the presence of specific chemical compounds using qualitative and
quantitative analysis methods.
Moisture Content: Assess the moisture content, as it can affect the stability and quality of the crude drug.
Ash Content: Measure the ash content to evaluate the inorganic material present.
Physicochemical Properties:
Solubility: Determine the solubility of the crude drug in different solvents.
pH: Measure the pH of the crude drug to assess its acidity or alkalinity.

16. Biological Evaluation:
Bioactivity: Conduct tests to determine the biological activity of the crude drug, such as antimicrobial or anti-
inflammatory properties.
Toxicity: Evaluate the toxicological profile to ensure safety for human use.
Authentication:
Botanical or Source Authentication: Confirm the identity of the plant or substance using taxonomic methods.
Geographical Authentication: Determine the origin of the crude drug, as it may influence its quality.
Quality Control:
Standardization: Establish quality standards for the crude drug based on the desired therapeutic compounds.
Storage and Handling: Ensure proper storage conditions to maintain the integrity of the crude drug.