Classification of Crude Drug

Hello readers, this blog is basically about the classification of crude drugs in pharmacognosy and their advantages, disadvantages with examples.

So what is Crude Drug..?

         Crude Drugs are animal or plant drugs that are undergone no other process other than collection and drying.
The term 'Crude Drug' is referred to in relation to a natural product that has not been improved in condition by any process or treatment beyond that which is essential for its packing and prevention from deterioration.

The Crude Drugs are grouped as below-

Organized Drug
Unorganized Drug

Characteristics	Organized Drug	Unorganized Drug
Definition	A drug that represents a part of any plant or animal made up of cells.	The Drugs which do not represent any part of plant or animal.
Identified by	Morphological Characters.	Organoleptic Characters.
Obtained From	Plants and Animals	Plants Animals and Minerals
Characters	Cellular in Structure, like Leaves, Fruit, Bark, Wood, and Solid in nature.	Solid, Semisolid, and Liquid in nature and do not have Cellular Structure like resins, mucilage.
Study	Transverse Section is studied under the microscope.	Physical parameters like density, optical rotation, viscosity, R.I., and chemical test.
Example	Leaves - Senna,Digitalis Wood - Sandalwood Bark - Cinchona, Cinnamon Flower - Clove Fruit - Dill, Coriander Seed - Nux-vomica, Black mustered Rhizome - Ginger, Squill Fibers - Hemp, Flax, Silk.	Dried Latex - Opium Dried Juice - Aloe, Kino Dried Extract - Black Catechu Gum - Acacia Resin - Storax, Asafoetida Fixed Oil - Olive oil, Linseed oil Animal Product - Beeswax, Gelatin Fossils - Talc, kaolin.

In pharmacognosy, the crude drugs are classified according to-

• Their Alphabetical status
• The Taxonomy of plants and animals.
• Their Chemical nature
• Their Morphology
• Chemo-taxonomical status
• Pharmacological
• Sero-taxonomical status

So, let's see these classifications in detail. You can directly go to the desired classification by using the below links for convenience or you can scroll through.

Alphabetical Taxonomical Chemical Morphological Pharmacological Chemo-taxonomical Sero-Taxonomical

Alphabetical Classification

                 In this method, the drugs are arranged in alphabetical order of their English or Latin names. It is used in official books like Indian Pharmacopeia, British Pharmacopeia, etc.

Advantages	Disadvantages
1. Provides quick reference. 2. The study of drugs is easy by knowing a name. 3. The addition and deletion of a drug are easy.	1. Fail to classify drugs based upon morphology and taxonomy. 2. No relation between successive and previous entries. 3. No link between constituents in the drug.

Example: 
Acacia, Bentonite, Cascara, Digitalis, Ergot, Fennel, Gokharu, Hemp, Isapgol, Jalap, Kino, Linolin, Myrrh, Nux-Vomica, Opium, Podophyllum, Quassia, Rauwolfia, Senna, Tragacanth, Uncaria gambier, Vasaka, Wool fat, Yellow bees-wax, Zedoary, etc.  

Taxonomical Classification

The drugs are classified according to plants or animals from which they are obtained in phyla, orders, families, genera, species, subspecies, etc. This method of classification is based on the consideration of natural relationship or phylogeny among plants or animals. It gives information in the systemic naming of organizations into similar groups.

Advantages	Disadvantages
1. Gives an idea about species (Varieties of organisms) 2. Helpful to study the evolutionary development of crude drugs.	1. No idea about chemical constituents and morphological nature 2. Most drugs do not assemble the whole plant. Minerals get excluded. 3. Tedious and time-consuming.

Example:

1. Phylum      - Spermatophyta

    Division     - Angiospermae

    Class         - Dicotyledons

    Order        - Rosales 

    Family       - Leguminosae

    Sub-family - Papilionaceae

    Genus        - Glycyrrhiza, Astragalus, Myroxylon

    Species      - Glycyrrhiza glabra, Astragalus gummifera, Myroxylon balasamum.

2. Phylum  - Thallophyta

    Class     - Ascomycetes

    Order    - Clavicipitales

    Family   - Clavicipitaceae

    Genus   -  Claviceps

    Species - Claviceps purpurea

Chemical Classification

Crude drugs are divided based on the chemical nature of their important constituent or names of constituents. It would appear that the chemical classification of the crude drug is the preferred method of study.

Advantages	Disadvantages
1. Used for the phytochemical study. 2. Pharmacologically active constituents and therapeutic significance of crude drugs depend on the nature of their chemical constituents.	1. Improper placement of drugs containing two different types of chemicals as in the case of Nutmeg (Fixed and Volatile oil). 2. No idea about morphology and the source of drugs.

Example: 

Alkaloids  -  Nux vomica, Cinchona, Datura

Carbohydrates - Acacia, Agar, Guar gum, Pectin, Honey, Ispaghula

Glycosides       - Digitalis, Senna, Cascara

Lipids              - Castor oil, Beeswax, Cod liver oil, Kokum butter

Proteins, and Enzymes - Casein, Trypsin, Papain, Gelatin

Resins     - Colophony, Jalap, Balsam of Tolu

Tannins   - Pale catechu, Ashoka

Vitamins - Yeast, Shark liver oil 

Volatile oil - Peppermint, Clove, Garlic, Eucalyptus

Morphological Classification

Crude drugs are divided based on external characters of plant or animal part represented into organized and unorganized drugs.

Advantages	Disadvantages
1. Easy to study drugs. 2. Easy to identify and detect adulteration. 3. Easy to handle.	1. Identification of crude drugs with similar morphology can not be identified.

Example: 

Barks             -   Cinchona, Kurchi, Cinnamon

Dried extract  -   Catechu, Agar, Gelatin

Dried juices    -   Redgum, Aloes, Kino

Dried latices   -   Opium, Gutta-percha, Papain

Entire drugs    -   Ephedra, Ergot, Cantharides, Belladonna

Flowers          -   Clove, Saffron, Pyrethrum, Artemisia

Fruits             -    Coriander, Fennel, Bael, Colocynth

Gums             -   Acacia, Ghatti gum, Guar gum, Tragacanth

Leaves           -   Senna, Digitalis, Eucalyptus, Vasaka

Resins            -   Balsam of Tolu, Myrrh, Benzoin

Rhizomes       -   Turmeric, Ginger, Podophyllum, Valerian

Roots            -    Jalap, Aconite, Rauwolfia

Seeds            -   Nux-vomica, Isabgol, Castor, Strophanthus

Woods           -   Sandalwood, Quassia, Red sanders, Sassafras

Pharmacological Classification

Crude drugs are divided based on pharmacological action and therapeutic use of their chief active chemical constituent. It is also known as the Therapeutic Classification of crude drugs.

 

Advantages	Disadvantages
1. Due to chemical constituents, we can imply its pharmacological action. 2. Easy to study drugs. 3. It is based on the active constituent of the drug.	1. Some drugs have two similar pharmacological actions and difficult to classify, for example, Nux-Vomica shows two actions like CNS stimulant and Bitterent also. 2. Drugs that have different mechanisms of action are grouped together. 3. Drugs that have two or more similar chemical constituents failed to state taxonomical properties.

Example:

Anticancer  - Vinca, Podophyllum, Taxus

Antirheumatics - Aconite, Colchicum, Guggul

Anthelmintics   - Quassia, Male Fern, Vidang

Antispasmodics - Opium, Datura, Hyoscyamus, Curare

CNS stimulants  - Coffee

CNS depressants - Hyoscyamus, Belladonna, Opium(Morphine, Codeine)

Analeptics      -  Nux-vomica, Camphor

Hallucinogenics  - Cannabis, Poppy Latex

Central analgesics - Opium (Morphine)

Local anesthetics - Coca 

Astringents    -  Black Catechu, Myrobalon

Antimalarials   -  Cinchona, Artemisia

Immuno-modulatory agents - Tulsi, Ashwagandha, Ginseng, Asparagus

Bitters  -  Quassia, Cinchona

Carminatives  -  Dill, Fennel, Cardamom

Emetics  -  Ipecacuanha

Antiamoebics  -  Kurchi, Ipecacuanha

Expectorants  -  Vasaka, Liquorice

Chemo-taxonomical Classification

Firstly Bentham and Hooker have explained this combined classification, crude drugs are divided based on the relation between chemical composition and taxonomical position of plant or animal from which crude drug is obtained.

 Chemo-taxonomy establishes a relationship between the position of the plant and attempts to utilize chemical facts for the more exact understanding of biological evolution and relationships.

Advantages	Disadvantages
1. Gives the relationship between chemical constituent, their biosynthesis, and possible actions. 2. Provide Hybridization and breeding analysis. 3. Provide secondary metabolites of pharmacological significance such as alkaloids, glucoside, flaronoids, etc.	1. Fails to understand the therapeutic nature of crude drugs. 2. Fails to identify organized and unorganized drugs in morphological studies.

Example:

          1. Berberine alkaloid in Hydrastis, Berberis, and Argemone

          2. Rutin and Ranunculaceous alkaloids and Flavonoids in species of higher plants

          3. Tropane alkaloids belonging to the Solanaceae family.

Sero-Taxonomical Classification

Sero means Serology which involves the study of antigen-antibody reaction and taxonomy belongs to taxonomical classification. It is defined as serological concepts applied to the taxonomical classification of plants, protein-antigen, and its presence or absence in plants. Example plantA & B are compared on the basis of the degree of similarity in reaction with a particular texa.
The Fair-Brothers in 1987 was given the application of serology to the classification of crude drug and it is mostly done with plants.

 

Advantages	Disadvantages
1. The analysis is done by the analytical method. 2. If a molecule is an unchanged relationship can be traced back in time. 3. The size of data used in the molecular taxonomy study is enormous.	1. No familiar intermediate conditions between their characteristics. 2. No primitive conditions for DNA sites to be recognized.

Example:

              Two or more plants showing the same serology i.e. having more degree of similarities in Antigen(Protein)-Antibody reaction are grouped together.

Hope you like this Classification of Crude Drug . If you have any suggestions or need any help let us know in the comments below...