PCOG LEC2

• The most important natural sources of drugs

  • Higher plant
  • Microbes
  • Animals
  • Marine organisms
• Some useful products are obtained from minerals that are both organic and inorganic in nature
• In order to pursue the study of the individual drugs

  1. Adopt some particular sequence of arrangement

  2. This is referred to as a system of classification of drugs
• Method of classification


  • Should be simple, easy to use, free from confusion and ambiguities
• CLASSIFICATION OF CRUDE DRUGS

  • Alphabetical Classification
  • Taxonomical Classification
  • Morphological Classification
  • Pharmacological Classification
  • Chemical Classification
  • Chemotaxonomical Classification
  • Serotaxonomical Classification
• Alphabetical Classification


  Simplest way of classification, crude drugs are arranged in alphabetical order of Latin and English (common) or local language (vernacular) names
• Pharmacopoeias, dictionaries and reference books using Alphabetical Classification

  • Indian Pharmacopoeia
  • British Pharmacopoeia
  • British Herbal Pharmacopoeia
  • United States Pharmacopoeia and National Formulary
  • British Pharmaceutical Codex
  • European Pharmacopoeia
• Merits of Alphabetical Classification

  • Easy and quick to use
  • No repetition of entries and devoid of confusion
  • Easy location, tracing and addition of drug entries
• Demerits of Alphabetical Classification

  • No relationship between previous and successive drug entries
• Taxonomical Classification


  Drugs are classified according to kingdom, subkingdom, division, class, order, family, genus and species
• Merits of Taxonomical Classification


  • Helpful for studying evolutionary developments
• Demerits of Taxonomical Classification


  • Does not correlate the chemical constituents and biological activity of the drugs
• Organized drugs


  • Drugs obtained from direct plant parts containing cellular tissues
  • Roots
  • Rhizomes
  • Barks
  • Leaves
  • Stems
  • Fruits
  • Entire plants
  • Hairs
  • Fibers
• Unorganized drugs


  • Drugs prepared from plants by intermediate physical processes without cellular plant tissues
  • Aloe juice
  • Opium latex
  • Agar
  • Gambir
  • Gelatin
  • Tragacanth
  • Benzoin
  • Honey
  • Beeswax
  • Lemon grass oil
• Morphological Classification


  Drugs are arranged according to the morphological or external characters of the plant parts or animal parts