Introduction
Adulteration of crude drugs is a major problem in the herbal and natural product industry. Due to improper identification, scarcity of genuine raw materials, commercial pressure and lack of standardization, many herbal drugs are mixed or substituted with inferior or harmful substances. This reduces the quality, purity and therapeutic value of herbal medicines.
Definition of Adulteration
Adulteration means intentionally or unintentionally replacing or mixing a genuine crude drug with inferior, substandard, useless or harmful materials. These substituted substances are called adulterants. The final material obtained is known as adulterated product.
Objectives Behind Adulteration
- To increase bulk or weight.
- To improve appearance.
- To give false strength or colour.
- To replace costly drugs with cheap substitutes.
- To compensate scarcity of genuine drugs.
Conditions Leading to Adulteration
1. Deterioration
Deterioration occurs when the quality of the drug reduces due to improper drying, storage, aging or removal of valuable constituents. Exposure to heat, moisture, light or microorganisms can destroy active ingredients.
2. Admixture
This happens when a crude drug gets mixed with other materials accidentally or due to carelessness. Soil, dust, unwanted plant parts or similar species may get mixed unintentionally.
3. Sophistication
This is a deliberate and fraudulent practice where inferior or spurious materials are added to imitate the genuine drug. Example: mixing starch and colouring matter with powdered ginger.
4. Substitution
Substitution occurs when a completely different drug is supplied instead of the original one. Example: supplying cottonseed oil instead of olive oil.
5. Inferiority
This refers to using a drug with naturally low levels of active constituents. Inferior-quality crops are used due to poor cultivation practices.
6. Spoilage
Spoilage occurs due to microbial attack or insect infestation. Fungal growth, bacterial contamination and worms make the drug unfit for use.
Types of Adulteration
Adulteration can occur in two main ways:
- Direct adulteration – intentional mixing or substitution.
- Indirect adulteration – unintentional issues arising from collection, processing or storage.
Direct Adulteration
1. Adulteration with Artificially Manufactured Substances
Artificial materials are made to resemble the genuine drug in colour and shape. Examples:
- Pressed chicory for coffee.
- Yellow-coloured paraffin wax for beeswax.
- Cut and shaped basswood for nutmeg.
- Artificial invert sugar for honey.
2. Substitution with Superficially Similar Inferior Drugs
Inferior drugs that look similar to original ones are used as substitutes. Examples:
- Ailanthus leaves for belladonna leaves.
- Carthamus flowers for saffron.
- Japan wax for beeswax.
- Arabian or dog senna for Indian senna.
3. Use of Exhausted Drugs
Exhausted drugs are those from which active constituents have been removed. These are supplied as if they are genuine. Examples include cloves or fennel seeds after removal of volatile oils.
4. Use of Synthetic Chemicals
Chemicals are added to enhance colour, flavour or aroma. Examples:
- Benzyl benzoate added to balsam of Peru.
- Citral added to lemon or orange oils.
5. Substitution with Extracted Drug Residue
Drug residue left after extraction is mixed with genuine material. Colour or odour may be artificially improved.
6. Harmful Adulterants
Dangerous substances are added to increase weight or mimic appearance. Examples:
- Glass pieces in colophony.
- Lead shot in opium.
- Limestone in asafoetida.
- Rodent faecal matter in cardamom.
7. Adulteration of Powdered Drugs
Powders are easily adulterated due to their uniform appearance. Examples:
- Dextrin added to ipecacuanha.
- Brick powder mixed with Mallotus phillipensis.
- Exhausted ginger mixed with genuine ginger powder.
Indirect Adulteration
1. Faulty Collection
Incorrect plant parts or wrong species may be collected due to lack of knowledge or similarity in appearance. Examples:
- Collecting non-medicinal Aconitum species instead of Aconitum napellus.
- Confusion caused by same vernacular name for different plants (e.g., Punarnava).
- Flowers of Calophyllum inophyllum sold as Nagakesar instead of genuine Mesua ferrea.
2. Imperfect Preparation
Improper cleaning, drying or processing leads to unintentional adulteration. Examples:
- Drying digitalis leaves at high temperature causes loss of glycosides.
- Poor separation of plant parts may mix stems or bark with leaf drugs.
3. Incorrect Storage
Exposure to air, moisture, heat or light results in deterioration. Microbial contamination also occurs during poor storage. Volatile oils become rancid, while leaves like belladonna lose active compounds.
4. Presence of Vegetative Matter
Other plants growing in the same field or small plant fragments get mixed accidentally. Lower plants like moss, epiphytes and unwanted seeds may be mixed with genuine drugs.
Detailed Notes:
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