Drug Adulteration and Types PDF

## Analytical Pharmacognosy ### Drug Adulteration and Types Adulteration is the practice of substituting the original crude drug with other similar-looking inferior, useless, and harmful substances. Adulteration in simple terms is debasement of an article. The main purpose of adulteration is com...

## Analytical Pharmacognosy ### Drug Adulteration and Types Adulteration is the practice of substituting the original crude drug with other similar-looking inferior, useless, and harmful substances. Adulteration in simple terms is debasement of an article. The main purpose of adulteration is commercial and is done purposely to cheat and to earn more money. Adulteration is practiced when the drug is scarce or when the price of a drug is high in the market. Adulteration is normally done deliberately, but it may also occur due to faulty collection, imperfect preparation, transportation and identification, and incorrect storage. If adulteration occurs accidentally, this type of unintended adulteration is called **undeliberate adulteration.** ### Undeliberate Adulteration Undeliberate adulteration may occur due to the following reasons: - **Faulty collection**: The collection of crude drugs during correct seasons or age is very important to avoid any adulteration. This is because, in some plant species, the presence of medicinally active principles reaches a maximum at a particular age, season or stage of development. Solonaceous leaves should be collected during summer, if the leaves are collected during spring season, it results in adulteration by faulty collection. ### Deliberate Adulteration There are a number of adulterants, which are deliberately substituted by the adulterators for commercial purpose and this type of adulteration is called deliberate adulteration. Adulteration involves different conditions such as deterioration, admixture, sophistication, substitution, inferiority and spoilage. - **Deterioration**: is an impairment in the quality of drug. - **Admixture**: is addition of one article to another due to ignorance or carelessness, or by accident. - **Sophistication**: is the intentional or deliberate type of adulteration. - **Substitution**: occurs when some totally different substance is added in place of the original crude drug. - **Inferiority**: refers to any substandard drug - **Spoilage**: is due to the attack of microorganisms. ### Types of Adulterants Generally drugs are adulterated with substandard commercial varieties, inferior drugs, artificially manufactured substance, exhausted drugs, synthetic chemicals, vegetative matter from the same plant, and non-plant materials. The different types of adulterants found in the market are given below. - **Substitution with substandard commercial varieties**: In this type, the substituted products are very similar in appearance to the original drug. Hence, the adulterants used here may resemble the original crude drug by morphological, chemical, and medicinal characters, but are substandard in nature, therefore, cheaper in cost. This type is a rather very common practice of adulteration. Some examples are as follows: | Drug | Materials substituted | |---------------------------|--------------------------------------------| | Strychnos nux-vomica | Strychnos potatorum, Strychnos nux-blanda | | Indian senna | Arabian senna, dog senna | | Ginger | African, Japanese and Cochin ginger | | Ashoka bark (Saraca indica) | Trema orientalis, Polyalthia longifolia | - **Substitution with superficially similar inferior drugs**: In this type, inferior drugs are substituted and they may or may not have any chemical or medicinal value as that of the original drug. Due to their morphological resemblance to the original drug, they are marketed as adulterants. Some of the examples are as follows: | Drug | Substituted materials without medicinal values | |------------------------|-------------------------------------------------| | Black pepper | Papaya seeds | | Coffee powder | Tamarind seed powder | | Black mustard seeds | Argemone seeds | | Saffron | Carthamus tinctorius | | Clove buds | Clove stalk and dried leaves | | Coriander powder | Faecal matter of donkey | | Cinnamon bark | Cassia | | Beeswax | Japan wax | | Senna leaves-Cassia angustifolia | Leaves of Cassia auriculata | | Paddy grains | Small white stones | - **Substitution with artificially manufactured substances**: In this type, substances that are artificially prepared to resemble original drugs are used as substitutes. This method is practiced for much costlier drugs. Some examples are as follows: | Drug | Substituted materials without medicinal value | |------------------------|-------------------------------------------------| | Coffee powder | Compressed chicory powder | | Beeswax | Yellow-coloured paraffin wax | - **Substitution of exhausted drugs**: In this type, the same drug is admixed, but it is without any medicinal value, as they are already extracted out. Some examples are as follows: | Drug | Exhausted drugs | |---------------------------|----------------------------| | Tea leaves, ginger | Used tea leaves | | Pepper seeds, liquorice | Used pepper seeds | | Cumin seeds | Used cumin seeds | | Fenugreek | Used fenugreek seeds | | Fennel | Used fennel seeds | - **Substitution with synthetic chemicals**: Sometimes, synthetic chemicals are added to enhance the natural character as in the case of addition of benzyl benzoate to balsam of Peru, citral to citrus oils like lemon oil and orange oil, etc. Similarly drugs like oleo gum-resin, myrrh, gum kino, balsam of Tolu, etc. are also adulterated with different products of similar nature as a matter of routine. - **Substitution of vegetative matter from the same plant**: Sometimes, the other plants growing along with medicinal plant are mixed with the drug due to their resemblance in colour, odour, and in some cases in similar constituents. Lower plants like moss, liverworts and epiphytes growing on bark portion are mixed with Cascara or Cinchona, and Lichens (Kalpasi). The stem portions are mixed along with leaf drugs like Stramonium, Lobelia, and senna. - **Substitution with harmful adulterants**: Several times, wastes from the market are collected and admixed with authentic drugs. This is particularly noticed for liquids or unorganized drugs. Some examples are as follows: - In colophony, pieces of amber-coloured glass are mixed. - In asafoetida, limestone is mixed. - In opium, lead shot is mixed. - In coconut oil, cocoa butter is adulterated with stearin or paraffin. These adulterations are very common practice in the market. - Rodent faecal matter is added to cardamom seed and is a very harmful adulterant. - **Substitution of powders with non-plant materials**: Adulteration with non-plant materials or powder to a particular original crude drug is very common nowadays in the market. For example: - Nux-vomica powder is mixed with olive stone powder. - Asafoetida is adulterated with gum arabic, red clay, gum resins, rosin, etc. - Nutmeg is mixed with broken kernels moulded with clay and shaped pieces of wood. The powdered forms are also frequently found to be adulterated. | Original powdered drug | Adulterated powder | |---------------------------|------------------------------------------------------------------------------------| | Ipecacuanha | Dextrin | | Liquorice, gelatin | Powdered olive stones | | Colocynth, ginger | Exhausted ginger powder | | Chilli powder | Red sandalwood, brick powder | | Coriander powder | Powdered faecal matter of donkey | ### Methods of Drug Evaluation Evaluation of drugs deals with the correct identification and determination of quality and purity of the crude drugs. - **Identity**: denotes the correct identification of the origin or biological source of the drug. - **Quality**: denotes the quantity of the active constituents present in the drug. - **Purity**: denotes the amount of foreign materials present in the drug. The evaluation of a crude drug is necessary to find out the following: 1. biochemical variation in the drugs. 2. deterioration due to treatment and storage. 3. substitution and adulteration, as a result of carelessness, ignorance or fraud. ### Morphological (or) Organoleptic Methods Organoleptic evaluation is done by means of our organs of sense, which includes external morphology and other sensory characters like odour, colour, taste, texture, and nature of fracture. ### Study of Morphological Characters Proper authentication of a drug depends almost entirely on morphological characters. Most of the crude drugs are derived from a part of a plant. The morphological or macroscopical study of the respective part is done by observing it with the naked eye or with the aid of magnifying lens. The plant parts that are used as crude drugs are the stem, bark, underground structures, leaves, flowers, fruits, seeds and herbs. For each group, a particular systematic examination should be carried out. - **i. Stem**: The characteristics used for the correct identification of stem are as follows: Dimensions, form, colour, position (erect or prostate), consistency (woody or herbaceous), presence or absence of structures like glands, thorns, spines, prickles, hairs, etc. - **ii. Barks**: Barks are the tissues in a woody stem present outside the vascular cambium or in roots. Barks may be broken or complete around the stem or roots. Barks are collected by stripping from the trunk or branches of the trees and are thus obtained as relatively narrow strips, e.g. Cinchona, Quillaia, cinnamon, ashoka, kurchi bark, etc.