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Classification of crude drugs
The crude drug is the unprocessed form of drug, which are directly obtained from natural sources like plants, animals and minerals, etc. For the proper and adequate study of crude drug, it is necessary to arrange them in scientific and systemic manner.
The classification of crude drugs is an essential step in the development and production of effective medicines. It involves analyzing the drugs’ chemical structures and pharmacological properties so that they can be grouped into categories based on their active ingredients, therapeutic uses, toxicity levels, and more.
They are classified into seven types:
1. Alphabetical classification
2. Morphological classification
3. Pharmacological classification
4. Chemical classification
5. Taxonomical classification
6. Chemo-taxonomical classification
7. Sero-taxonomical classification
1. Alphabetical classification of crude drugs
It is the simplest way of classification of crude drugs. In this classification the crude drug is arranged according to their alphabets. Most of the reference book and the pharmacopoeia are arrange according to the Latin or English name they are:
1. British pharmacopoeia
2. British pharmaceutical codex
5. British herbal pharmacopoeia
Merits of alphabetical classification
1. Easy and quick in use.
2. No repetition of drug
Demerits of alphabetical classification
1. Scientific nature of drug can’t be identified.
2. Original source is not clear.
Example of alphabetical classification
Acacia, Agar, Benzoin, Cinchona, Cinnamon, Digitalis, Fennel, Linseed, Mustard, etc.
2. Morphological classification of crude drugs
In this classification, drugs are arranged according to their morphological character such as their shape, size, part of plants/animals. The crude drugs are classified in organized and unorganized manner:
|Root||Rauwolfia, Liquor ice|
|Fruits||Opium, Bael, Fennel|
|Seed||Almond, Coffee, Beans|
|Entire plants||Vinca (Visiting, Vinblastine)|
|Fixed oil||Castor oil|
|Volatile oil||Eucalyptus, Sandalwood oil|
|Juice||Amla, Aloe vera|
|Gum||Tragacanth, Acacia, Guar|
Merits of morphological classification
1. Very useful in identifying the adulterant used.
2. More convenient for practical study.
Demerits of morphological classification
It does not give an idea about chemical constituents and uses.
3. Pharmacological classification of crude drugs
According to this classification, the crude drug is classified in pharmacological in therapeutic activity. It is more relevant classification and widely used, they are as follow:
|Carminatives||Fennel, Clove, Coriander, Cinnamon|
|Anti inflammatory||Turmeric, Colchicum|
|Anti spasmodic||Datura, Hyoscyamus|
Merits of pharmacological classification
They classified according to their therapeutic action, so they are easy in use event their chemical consequence is not known.
Demerits of pharmacological classification
Regardless of morphology, taxonomical or chemical nature, the drugs are grouped together due to their same pharmacological uses.
4. Chemical classification of crude drugs
In this classification, the drug is arranged according to the chemical or active constituents present on crude drug, they are as follows:
Merits of chemical classification
Chemical constituents and medicinal uses are known.
Demerits of chemical classification
Drugs of different origin are grouped together under similar chemical titles.
5. Taxonomical classification of crude drugs
In which, drugs are arranged according to their kingdom class, phylum class, order, family and species. It is the best method for classification of crude drugs.
Merits of taxonomical classification
1. Easy to use.
2. Helpful for studying evolutionary developments.
Demerits of taxonomical classification
This system failed to tall about chemical nature and therapeutic significance of crude drugs.
6. Chemo-taxonomical classification of crude drugs
In this classification, the equal importance is given for taxonomical status and chemical constituents. This classification is based on the chemical similarities of a taxon based on the existence of the relationship between the plant & it’s constituents. In this plant secondary metabolites are taken into consideration. Researches have printed already regarding the similarities of constituents from different plant species of a Gene. It is the best method for classification of crude drugs.
7. Sero-taxonomical classification of crude drugs
The study of antigen-antibody reaction is called serology. The application of serology in solving taxonomic problems is called sero-taxonomical. serology can be defined as the study of Antigens, Antibody reaction. It is the best method for classification of crude drugs.
Antigens are those substance which can stimulate the formation of antibody.
Antibody is the highly specific protein molecule produced by plasma cell in the immune system.
This classification expresses the similarities and dissimilarities among different taxa. It determines the degree of similarities between species ‘Genera’ or ‘Genus’, family, etc by comparing the reaction with antigen from various plant taxa with antibodies present against a given taxan.