These free B.Pharm notes on classification of crude drugs cover chapter 6 of Introduction to Pharmacognosy, a first-semester subject. Read the key points below, then study the complete chapter PDF. You can browse every chapter in the Introduction to Pharmacognosy category.
Table of Contents
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Overview of classification of crude drugs
This chapter explains crude drugs and their division into organized and unorganized drugs. It then describes seven methods of classification: alphabetical, taxonomical, morphological, pharmacological, chemical, chemotaxonomical and serotaxonomical, with examples and the advantages and disadvantages of each. It also lists the advantages and disadvantages of each method, so students can compare them and choose the right system for a given purpose.
Key points on classification of crude drugs
- Organized drugs have a definite cellular structure and come from plant parts such as roots, leaves and bark, while unorganized drugs have no cellular structure, like gums, resins and latex.
- The seven methods of classification are alphabetical, taxonomical, morphological, pharmacological, chemical, chemotaxonomical and serotaxonomical classification.
- Alphabetical classification arranges drugs by name and is used in pharmacopoeias, but it gives no information on source, chemical composition or pharmacological activity.
- Pharmacological classification groups drugs by their therapeutic action, such as cardiotonics, laxatives and anti-malarials, and it helps to select a substitute with similar action.
- Chemical classification groups drugs by constituents like alkaloids, glycosides, tannins and volatile oils, whatever their morphology or taxonomy, and is useful for standardisation.
Relevance to pharmacy practice
Classification helps a pharmacist find, compare and identify crude drugs quickly, and link them to their uses. Pharmacological and chemical classification are especially useful when a substitute drug with similar action is needed in practice.
Every chapter in this subject builds on the one before it, so do not skip topics that look simple. Definitions, classifications and examples are the parts that examiners return to most often, and a clear understanding here will also make later subjects easier to follow in the coming semesters.
Frequently asked questions on classification of crude drugs
What is the difference between organized and unorganized drugs?
Organized drugs have well-defined cellular structure and are studied by microscopy, like cinchona bark and senna leaves. Unorganized drugs lack cellular structure and are evaluated by physical and chemical properties, like gums and resins.
What are the methods of classification of crude drugs?
There are seven methods: alphabetical, taxonomical, morphological, pharmacological, chemical, chemotaxonomical and serotaxonomical classification. Different systems are used for different purposes because no single method meets all needs.
What is chemotaxonomical classification?
It classifies plants by their chemical constituents, combining taxonomy and phytochemistry. For example, Datura, Belladonna and Hyoscyamus of family Solanaceae all contain tropane alkaloids such as atropine.
Quick revision checklist
Use this self-test after reading the chapter on classification of crude drugs. If you can do all of the following without looking at your notes, you are ready for the exam.
- I can explain: organized and unorganized crude drugs
- I can explain: the seven methods of classification
- I can explain: alphabetical and taxonomical classification
- I can explain: morphological and pharmacological classification
- I can explain: chemical, chemotaxonomical and serotaxonomical classification
Study and exam tips
Start by reading the chapter once for the overall idea, then revise classification of crude drugs using headings, definitions, classifications and examples. Short-answer questions in the university exam usually ask for definitions, features, advantages, disadvantages and examples, so write these in your own words and practise drawing the tables and flow charts that the chapter has.
For wider reading, standard textbooks and open resources such as the NCBI Bookshelf help you confirm terms and see more examples. Revise classification of crude drugs again a day later and again a week later, because spaced revision improves long-term memory.
This page is part of the Introduction to Pharmacognosy series for first-semester B.Pharm students on B.Pharm Guru, where every chapter has a short summary and a full PDF. Bookmark this page and share it with classmates who are preparing for the same exam.
Related notes: 8. PLANT HORMONES AND APPLICATIONS IN MEDICINAL PLANT CULTIVATION, 9. POLYPLOIDY, MUTATION AND HYBRIDIZATION IN SECONDARY METABOLITES.
Next: 7. METHODS OF PLANT CULTIVATION AND GAP-GCP GUIDELINES. Back to the Introduction to Pharmacognosy category.
