ADULTERATION AND EVALUATION OF CRUDE DRUG
Adulteration or substitution of the crude drugs may be help in few cases such as when there is lack of an authentic plant. But the substitute drug must have same pharmacological effect similar to that of authentic plant with very less side effects.
Adulteration means replacing of original crude drug with other similar looking drug but not same with original drug while considering its therapeutic effects.
Types of Adulteration:
Adulteration can be broadly classified into two types
Intentional adulteration is mainly encouraged by traders because these original crude drugs are highly costly. So hence they use cheaper variety to reduce the cost burdane and to gain profit.
Accidental adulteration occurs without bad intention of the manufacturers or suppliers mainly it occurs during collection of drugs because of same morphological features between two plants.
Methods of Adulteration
There are seven types of adulteration methods. They are:
Substitution with the sub-standard commercial verities
Substitution with artificially manufactured drug
Substitution by exhausted drugs
Substitution by superficially similar but cheaper natural substances
Substitution by the addition of worthless materials
Substitution by the addition of synthetic substance
Substitution of the different part of the plants
Substitution with the sub-standard commercial verities:
It is because of organoleptic similarity, that different substandard varities which are not having any therapeutic effect.
Capsicum annum have been used to adulterate Capsicum comarim,
Piper nigrum fruit is adulterated by Carica papaya seeds.
Substitution with artificially manufactured drug:
Artificially manufactured substances are used as a substitute for the original drug.
Yellow colored paraffin wax for bees wax,
Shaved basswood for nutmeg.
Substitution by exhausted drugs:
For some same plant material is mixed with drug having no active medicinal components as they have already been extracted out.
Volatile oil containing drugs,
Colouring matter containing crude drugs.
Substitution by superficially similar but cheaper natural substances:
Adulterated product has no relation with genuine material,that may or may not have any therapeutic effect or chemical component.
Ailanthus altissima are substituted for Atropa belladonna,
Stramonium and dandelion Anethum sowa with Anethum graveolens.
Substitution by addition of worthless or heavy materials:
Sometimes waste from the market are collected and admixed with the authentic drug. But these waste materials are harmful to humans and other living organisms.
Limestone in Asafoetida,
Mentanil Yellow in Turmeric powder,
Lead shot in Opium.
Substitution by addition of synthetic principles:
For many crude drugs synthetic chemicals are used to enhance natural character.
Citral is added to citrus oils,
Benzyl benzoate to Peru balsam.
Substitution of different parts of plant:
In case of senna its roots, branches, stems, fruits and flowers are added along with senna leaves during packaging to gain profit.
Reasons for adulteration:
There are many reasons for adulteration. They are:
Confusion in Vernacular names
Lack of knowledge about authentic source
Similarity in morphology
Lack of authentic plant
Similarity in Color
Confusion in Vernacular names:
Same vernacular name of different species and different in vernacular names of same species creates confusion and invites adulteration. In Ayurveda, Parpatta refers to Fumaria parviflora and in Siddha, Parpadagam refers to Mollugo pentaphylla. Owing to the similarity in the names in traditional systems of medicine, these two herbs are often adulterated or substituted.
Lack of knowledge about authentic source:
The authentic source is Mesua ferrea and however, market samples are adulterated with flowers of Calophyll uminophyllum because suppliers are unaware of it.
Similarity in morphology:
Similarity in organoleptic features mostly adulteration takes place. Because of similarity in colour or texture it happens.
Mucuna pruriensis adulterated with Mucuna utilis and Mucuna deeringiana are popular adulterants.
Lack of authentic plant:
Hypericum perforatum is cultivated and sold in European markets mostly. In India, availability of Hypericum perforatum species is very limited. So, however the abundant Indo-Nepal species Hypericum patulum, sold in the name of Hypericum perforatum in market.
Similarity in Color:
In the past, roots of the Ventilago madraspatana are collected from Western Ghats, as the only source of Ratanjot. It is clearly known that Arnebia euchroma is the present source of ratanjot.
Some of the herbal adulterations are due to the carelessness of herbal collectors and even suppliers. Parmelia perlata is used in Ayurveda, Unani and Siddha and it is also used as grocery. Market samples showed it to be admixed with other species even sometimes, Usnea is also mixed with them.
EVALUATION OF CRUDE DRUGS:
Definition of evaluation
Evaluation of crude drug means determination of identity, purity and quality of a drug. Evaluation of crude is most important to know whether the drugs are adulterated with other substance or not. Before using any crude drug it must be checked for its quality and purity.
Methods of evaluation
There are five methods for evaluating crude drug for its quality and purity by considering morphological, physical and chemical characteristics.
It includes the study of morphology and sensory characters. Two types are present
Size and Shape, Colour, Texture, Odour and Taste are useful in the evaluation of drugs.
Size and shape:
Each and every plant has its own shape for its fruits, leaves. And even a particular size is present.
Shape: Tragacanth- ribbon shaped,
Acacia- ovoid tear shaped.
Each and every crude drug or plant has its own color for its flowers, fruits and seeds.
Cardamom- green colour fruit
Cinnamon- brown color bark
Turmeric-yellow colour powder
Each and every plant has its own texture for better identification.
Fractured surface- cinchona.