Crude drugs are derived from a variety of natural sources like plants, animals, minerals, and microorganisms. Because of their wide distribution, the arrangement or classification of drugs in a particular sequence is necessary for their easy understanding. For pharmacognostic study crude drugs are classified as follows: Alphabetical classification Chemical classification Pharmacological classification Morphological classification Taxonomical classification Chemo taxonomical classification Each of these systems of classification has its merits and demerits.

1. Classification
of
Crude Drugs

2. Various system of classification of Crude Drugs
• Crude drugs are derived from a variety of natural sources like plants, animals, minerals, and
microorganisms. Because of their wide distribution, the arrangement or classification of drugs in a
particular sequence is necessary for their easy understanding.
For pharmacognostic study crude drugs are classified as follows:
• Alphabetical classification
• Chemical classification
• Pharmacological classification
• Morphological classification
• Taxonomical classification
• Chemo taxonomical classification
• Each of these systems of classification has its merits and demerits.

3. ALPHABETICAL CLASSIFICATION
In this method drugs are classified according to first alphabet of their English or Latin name.
This classification is based on official books like:
• Indian pharmacopoeia
• United state pharmacopoeia
• British pharmacopoeia
Ex. Acacia, benzoin, cinchona, digitalis, ergot, fennel, ginger, hyocymus, ipecacuanha, lalap, kuruchi, liquorice,
mints, nux-vomica, opium, podophyllum, quassia, rouwolfia, senna, tulsi, vasaka, wool fat, yellow bees wax etc.
• Advantages
 Simple method
 Easy and quick to use
 Addition of drug entries are easy.
 If we know the name, drug, we can study it properly.
• Disadvantages:
 The nature of the crude drug is not known. ie. Where it is organised of unorganised.
 This classification does not help in differentiate that drug obtain from plants, animals or mineral source.

4. CHEMICAL CLASSIFICATION
The activity of crude drugs is due to the presence of certain chemical
constituent in the drug. In this classification the crude drugs are classified
according to their chemical constituents.
• Advantages:
 If we know the chemical constituents it is very easy to study about the
drug.
 It is a popular approach.
• Disadvantages:
 This method does not give any idea about the source of the drug.
 This type of classification fails in proper placement of the drug which
having more than one chemical constituents. i.e. Cinchona contains
both alkaloids & glycoside.
 This type of classification fails to give idea about the organised or
unorganised crude drug.
Chemical
constituent
Drugs
Alkaloids Cinchona, Dhatura, Vinca, Ipecac,
Nux-vomica
Glycoside Senna, Aloe, Ginseng, Glycyrrhiza,
Digitalis
Carbohydrates and
derived products
Acacia, Tragacanth, Starch, Isabgol
Volatile oil Clove, Coriander, Fennel, Cinnamon,
Cumin
Resin and Resin
combination
Benzoin, Tolu Balsam, Balsam of
peru
Tannins Catechu, Tea
Enzymes Papain, Caesin, Trypsin
Lipid Bees wax, Lanolin

5. PHARMACOLOGICAL CLASSIFICATION
In this classification grouping the drugs according to their pharmacological action. Crude drugs are classified
according to the pharmacological action which shown by their chemical constituents.
• Advantages:
 By this classification it is vary easy to study about the drug.
 With the help of pharmacological classification, medicinal
importance of the drug is known easily.
 This classification is used for suggesting the substituents of the
drug if it is not available at particular place or time.
• Disadvantages:
 If some crude drugs have two different pharmacological action
then it is very difficult to classify them properly. i.e. cinchona is
tonic as well as anti malarial and antipyretic.
 It does not give any idea where the drug are organised or
unorganised.
 It does not give any idea about the source of drug.
Pharmacological
Action
Drugs
Anticancer Vinka, Podophyllum, Taxus
Anti-inflammatory Colchicum, Turmeric
Antiamoebic Ipecac root, Kuruchi bark
Antiasthmatic Ephedra, Lobelia
Antispasmodic Dhatura, Hyocyamus
Astringent Catechu
Analgesic Opium
Bitter tonic Quassia wood, Nux vomica
Carminative Coriander, Fennel, Clove, Peppermint
Purgatives Senna, Rhubarb
Expectorant Tulsi, Balsam of Tolu, Vasaka
Cardio tonic Digitalis, Squill

6. MORPHOLOGICAL CLASSIFICATION
Under this classification the crude drugs are arranged according to the morphology or external characters of plant parts like
roots, stems, fruits, seeds etc. The drugs which are obtained directly from the parts of the plant and contain cellular tissue are
called as organised drugs. The drug which are prepared from plant by some intermediate physical process such as incision,
drying and does not contain ant cellular plant tissue are called as unorganised drugs. E.g. Aloe juice, opium, latex, gelatine,
honey etc.
• Advantage:
 More convenient method for the practical purpose.
 It gives idea about the source of drug.
 It gives idea about the crude drug whether it is organised or
unorganised.
 Morphological classification is more helpful to identify and detect
adulteration
• Disadvantage:
 During collection, drying and packing morphology of the drug changes,
thus they are difficult to study by this method.
 Animals and marine drugs are difficult to classify by this method.
 Repetition of drugs and plants occurs.
Part of plant Drugs
Leaves Vasaka, Digitalis, Senna, Dhatura
Barks Cinnamon, Cinchona, Cascara, Ashoka
Flowers Clove, Pyrethrum, Artemisea
Seed Linseed, Mustard, Isapgol, Nux-vomica
Fruits Dill, Coriander
Roots Ipecacuanha, Rauwolfia, Aconite
Rhizomes Rhubarb, Turmeric, Ginger
Dried Latex Opium
Dried Juice Aloe
Dried extracts Agar, Catechu, Gelatin
Gums Tragacanth, Acacia, Guar gum

7. TAXONOMICAL CLASSIFICATION
It is purely botanical classification. In this system drugs are arranged according to the plant from which they are
derived in term of phylum, family, class and species.
• Advantage:
 Drugs are easy to arrange.
 Animal drugs are classified as arthropods, mammals.
 It is more scientific method.
 Helpful for studying evaluation developments.
 Disadvantage:
• It does not give any idea about chemical constituent.
• This system does not correlate therapeutic activity of the drug.

8. CHEMO-TAXONOMICAL
This is recent type of classification in which the equal importance is given for taxonomical status and chemical
constituents. There are certain types of chemical constituents which are characteristics of certain classes of
plants.
E.g.: Tropane alkaloids generally occur in most of the members of Solanaceae.
E.g.: Volatile oils occur in the members of Umbelliferae and Rutaceae.

9. Question Bank
1. Define crude drug. 2 marks
2. Name the various methods of classification of crude drugs. 2 marks
3. What do you mean by organised (Cellular) and unorganised (Acellular) crude drugs give examples. 5 marks
4. Describe morphological classification of crude drugs with examples. 5 marks
5. Explain chemical classification of crude drugs with examples. 5 marks
6. Explain pharmacological or therapeutic classification of crude drugs with examples. 5 marks
7. Write in detail alphabetical and taxonomical or botanical classification of crude drugs. 5 marks
8. Define chemotaxonomy. Give its significances or importance. 5 marks
9. Explain the differences between organised and unorganised crude drugs. 5 marks
10. Define crude drug. Explain various methods of classification of crude drugs with examples. 10 marks