Adulteration of drugs of natural origin

(S. Y.  B. Pharm Sem IV) Unit - I


AS per PCI Syllabus




Definition:

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.

Factors of adulteration: 

Deterioration: is the impairment in the quality of a drug.

Admixture: is the addition of one article to another due to ignorance or carelessness or by accident.

Sophisticaton: is the intentional or deliberate type of adulteration.

Substitution: occurs when some totally different substance is added in place of original drug.

Inferiority: refers to any sub-standard drug.

Spoilage: deterioration due to the attack of microorganisms.

Reasons of adulteration

1. Unintentional or indirect: 

 It occurs without any bad intention of manufacturer or suppliers mainly occur due to following reasons

  • Due to similarity in morphology & or aroma
  • Name confusion in vernacular name
  • Careless collection or storage
  • Lack of knowledge about authentic source
  • Lack or no availability of authentic plant


 2. Intentional adultration or Direct Adulteration:

 It occurs intentionally by manufacturer or suppliers mainly occurs due to following reasons.
  • To earn profit 
  • Due to high price of the drug in the market
  • Due to scarcity of drug


Types of Adulterants

Generally the drugs are adulterated by substitution with sub-standard commercial varieties, interior drugs, or artificially manufactured commodities.

Adulteration in simple terms is debasement of an article. The motives for intentional adulteration are normally commercial and are originated mainly with the intension of enhancement of profits.

Some of the reasons that can be cited here are scarcity of drug and its high price prevailing in market. The adulteration is done deliberately, but it may occur accidentally in some cases. 

The following types of adulteration are common:

1. Substitution with Sub-Standard Commercial Varieties :


The adulterants here may resemble the original crude drug in morphological, chemical, or therapeutic characters, but are sub-standard in nature and hence are cheaper in cost.
This is a rather most common practice of adulteration.
eg. Strychnous nux-blanda or S. potatorum in place of S. nux vomica, Capsicum annuum in place of C. minimum, Indian senna is substituted with arabian senna or dog senna, medicinal ginger is substituted with inferior varieties of African, Japanese, or Cochin ginger.

2. Substitution with Artificially Manufactured Substances :

It has been also observed that substances artificially prepared to resemble the original drug are used  as substitutes. 
This practice is followed for much costlier drugs.  Compressed Chicory in place of coffee, yellow coloured paraffin wax for bees wax properly cut and shaved baswood for nutmeg.

3. Substitution with Superficially Similar Inferior Drugs :

These inferior drugs used may or may not be having any chemical or therapeutic value as that of original drug. Due to their morphological resemblance to the authentic drug, they are marketed as adulterants.

Belladonna leaves are substituted with Ailanthus leaves, Saffron is admixed with dried flowers of Carthamus tinctorious, and bees wax is substituted with Japan wax.

4. Careless collections:

Some of the herbal adulterations are due to the carelessness of herbal collectors and suppliers.  Parmelia perlata is used in Ayurveda, Unani and Siddha. It is also used as grocery.

Market samples showed it to be admixed with other species (P. perforata  and  P. cirrhata ). Sometimes, Usnea sp. is also mixed with them. Authentic plants can be identified by their thallus nature.

5. Substitution with Exhausted Drug :

The same drug is admixed but is devoid of any medicinally active constituents as they are already extracted out.

 This practice is more common in case of volatile oil containing drugs like fennel,clove, coriander, caraway etc. 
Sometimes natural characters of exhausted drugs like color, and taste  are manipulated by adding other additives and then it is substituted, 

e.g. exhausted gentian made bitter with aloes, artificial coloring of exhausted saffron, etc.

6. Presence of Vegetative Matter from the Same Plant : 

Sometimes, the other miniature plants grwoing along with medicinal plants are admixed with authentic drug, due to their resembling colour, odour, and in some cases constituents.

The lower plants like moss, liverworts, and epiphytes growing on bark portion are mixed with cascara or cinchona.

The stem portions are mixed along with leaf drugs like stramonium, lobelia, and senna .
7. Besides these common practices, sometimes other methods are also employed like use of synthetic chemicals to enhance the natural character as in case of addition of benzyl benzoate to balsam of peru, citral to citrus oils like oil of lemon and orange oil, etc.

8. Adulteration of Powders
Besides the entire drug the powdered forms are frequently found to be adulterated.
Examples: dextrin in ipecacuanha, powered liqourice or gentian admixed with powdered olive stones, exhausted ginger powder in powdered colocynth or ginger, red-sanders wood in capsicum, etc.

9. Harmful Adulterants

Sometimes the waste from the market are collected and admixed with the authentic drug. This is particularly noticed for liquids or unorganized drugs.

The examples like pieces of amber colured glass in colophony, limestones in asafoetida, lead shot in opium, white oil in coconut oil, cocoa butter mixed with stearin or paraffin.

The addition of rodent fecal matter to cardamom seed is a very harmful adulteration.


Thank You.