CLASSIFICATION

1. CLASSIFICATION Different systems of classification for vegetable drugs

2. Medicinal drugs can be arranged under the following headings • 1- Alphabetical • Either use Latin or Vernacular name • This arrangement is employed only for dictionaries • Gives no indication about inter-relationship

3. 2- Taxonomic • Drugs are arranged according to plants from which they are obtained • Classes, orders, families, genera and species • e.g drugs from plants like • Square stem, opposite leaves and bilabiate flowers (peppermint, thyme) are considered from Labiatae

4. 3-Morphological • Drugs are divided into groups • 1- Organized drugs • Leaves, flowers, fruits, seeds, herbs entire organisms, woods, barks, rhizomes and roots. • 2- Un-organized drugs • Extracts, gums, resins, oils, fats and waxes.

5. 4-Therapeutic or pharmacological • R.Pratt and H.W.Youngken (1956) • Drugs are employed for their therapeutic effects, method of study called therapeutic classification. • e.g. senna, castor oil are considered because of their action on intestinal tract. • So this type of consideration forms the basis for science of pharmacology.

6. 5-Chemical or biogenetic • Constituents e.g alkaloids, glycosides, volatile oils etc. • Their biosynthetic pathway forms the basis of classification. • Some drugs contain constituents which are therapeutically active, some only chemically active. • Certain plant families exhibit definite type of chemical principles

7. Chemical classification • Solanaceae contain alkaloids (atropine, scopolamine) • Umbiliferae contains volatile oils • In a like manner, drugs containing volatile oils, or resins, or tannins, or glycosides can be classified in their perspective phytochemical groups.

8. Questions/Suggestions