This document discusses different methods of classifying crude drugs, including alphabetical, taxonomic, morphological, chemical, pharmacological, and chemotaxonomic classification. Each system is described briefly, along with its merits and demerits. The chemical and pharmacological classification systems group drugs based on their active chemical constituents and therapeutic effects, making these methods scientifically useful for studying crude drugs and recommending substitutes. However, chemical classification can result in confusion when drugs contain multiple compounds.

1. Classification
of crude
drugs
Miss.Gayatri Patra
Asst.professor
EPCP, Bangalore

2. Classification of crude
drugs
Alphabetical Classification
Taxonomical (Biological) Classification
Morphological Classification
Chemical Classification
Pharmacological (Therapeutical) Classification
Chemotaxonomic Classification

3. Alphabetical Classification
• The crude drugs are arranged according to the alphabetical order of their Latin and English names.
• Some of the Pharmacopoeias and reference books which classify crude drugs according to this system are as
follows:-
1) Indian Pharmacopoeia 2) British Pharmacopoeia 3) British Herbal Pharmacopoeia
4) United States Pharmacopoeia and National Formulary 5) British Pharmaceutical Codex 6) European
Pharmacopoeia.
Example :- Acacia, Ergot, Fennel, Myrrh, Nux vomica, Opium, Bees wax, Cinchona.
Merits :-The system is easily and quick use.
Location, tracking and adding drugs entries can be done easily
Demerits :- Scientific nature of the drug cannot be identified by this method, whether they are organized or
unorganized drug.

4. Taxonomical (Biological) Classification
• This drugs are classified according to plants (crude drugs) or animals from which they are
obtained in phylum, division, orders, families, genera, species, subspecies, etc.
• Merits:- Easy for the classification of crude drugs.
• Demerits :- It fails to recognized organized & unorganized nature of crude drugs in their
morphological studies.
• The system fails to face into an account chemical nature of active constituent and
therapeutic significance of crude drugs.
Phylum Spermatophyta
Division Angiospermae
Class Dicotyledons
Order Rosales
Family Leguminosae
Sub-family Papilionaceae
Genus Glycyrrhiza, Astragalus
Species Glycyrrhiza glabra, Astragalus gummifer

5. Morphological Classification
• The crude drugs are grouped according to the part of the plant or animal
represented in to organized and unorganized drugs.
TYPE OF CRUDE DRUGS EXAMPLES
ORGANISED DRUGS
Represent the parts of a plant and made up of
cells.
Fruits :-Coriander, Fennel
Leaves :-Vasaka, Datura, Senna, Degitalis
Bark :-Cinchona, Cinnamon
Seed :- Nux-Vomica, Isapghula
Root :-Rauwolfia, Liquorice
Flower :- Clove, Saffrone
UNORGANISED DRUGS
Does not contain plant part, but it is obtained
by varieties of extraction procedures.
Dried Extracts :- Agar, Black catechu, Pale
catechu
Fats :- Lard
Resins :- Colophony, jalap
Waxes :- Beeswax
Gum :- Acacia, Tragacanth

6. • Merits:- Identification and detection of adulteration using this system is not
difficult.
• Practical study by this classification is more.
• Demerits:- The chemical constituents have not correlation with the therapeutics
action.
• Repetition of drugs or plants may appear.

7. Chemical Classification
• The crude drugs are divided into different groups according to the chemical nature of
their most important constituent.
• Since, the pharmacological activity and therapeutic significance of crude drugs are
based on the nature of their chemical constituents, it would appear that chemical
classification of crude drugs is the preferred method of study.
• Few examples of the drugs under chemical classification are as follows :
• Glycosides :- Digitalis, Senna, Liquorice
• Alkaloids :- Nux vomica, Ergot, Cinchona, Datura
• Tannins :- Myrobalan, Pale catechu, Ashoka
• Volatile oils :- Peppermint, Clove, Garlic
• Merits:- Phytochemical studies are well performed through this system
• Demerits :- Confusion occurs when a drug contain many compounds belonging to
different groups

8. Pharmacological (Therapeutical) Classification
• This system of classification involves the grouping of crude drugs according to
the pharmacological action of their chief active constituent or their therapeutic
uses.
1.Drugs acting on gastro-intestinal tract :-
Bitters – Cinchona, Quassia
Carminatives – Dill, Cardamom
Emetics – Mustard, Ipecacuanha
Purgatives – Senna, Castor oil
Bulk laxatives – Agar, Ispaghula

9. 2.Drugs acting on respiratory system :-
Expectorant – Liquorice, Ipecacuanha, Vasaka
Antiexpectorants – Stramonium leaves (Atropine)
Antitussives – Opium
Bronchodilators – Ephedra, Tea
3.Drugs acting on cardio-vascular system :-
Cardio tonics – Digitalis, Squill
Cardiac depressants – Cinchona
Antihypertensives - Rauwolfia

10. 4.Drugs acting on autonomic nervous system :-
Adrenergics – Ephedra
Cholinergics – Pilocarpus
Anticholinergics – Belladonna, Datura
5.Drugs acting on central nervous system :-
Central analgesics – Opium(Morphine)
CNS Stimulants – Coffee(Caffeine), Tea, Cocoa
CNS depressants – Belladonna
6.Anticancer :- Vinca, podophyllum.
7.Local Anaesthetics :- Coca
Merits:- The classification system aids in recommending substituents of an unavailable
drugs
Demerits:- Drugs with different action on the body get classified into many groups thus
create confusion.

11. Chemotaxonomic Classification
• Chemotaxonomy is a branch of taxonomy that uses the chemical characteristics of
organisms, particularly the presence and concentration of specific chemical compounds, as a
basis for classification. In the context of crude drugs, which are plant or animal materials
used for medicinal purposes in their unrefined form, chemotaxonomy can provide insights
into their classification based on their chemical constituents.
1.Alkaloids:
Many plants contain alkaloids, nitrogen-containing compounds that often have pharmacological
effects. Examples include morphine, quinine, and caffeine.
2.Glycosides:
Glycosides are compounds containing a sugar molecule and a non-sugar component (aglycone).
Examples include cardiac glycosides found in Digitalis species.

12. 3.Essential Oils:
Essential oils are volatile compounds responsible for the characteristic aroma of
plants. They often have medicinal properties. Examples include menthol from mint
and eucalyptol from eucalyptus.
4.Tannins:
Tannins are polyphenolic compounds that can have astringent properties. They are
found in many plant species, such as in the bark of some trees.
Merits:-This classification system is recent and provide better understanding of the
relation ship between chemical constituents , their biosynthesis and action
Demerits:- It is complex to recognize the chemical in plants Hence it is also a time
consuming process