These free B.Pharm notes on powders cover chapter 9 of General Pharmacy, a first-semester subject. Read the key points below, then study the complete chapter PDF. You can browse every chapter in the General Pharmacy category.
Table of Contents
Read the following document for full information
Chapter overview
Powders are among the oldest solid dosage forms. This chapter covers their properties, the importance of uniform particle size, extemporaneous comminution methods (trituration, pulverisation by intervention and levigation), classification, advantages and disadvantages, and official preparations such as aspirin powder, calcium carbonate powder, activated charcoal powder and compound powders.
Key points on powders
- A powder is a mixture of finely divided drugs and excipients intended for internal or external use.
- Uniform particle size ensures content uniformity, good mixing and consistent dissolution.
- Trituration, pulverisation by intervention and levigation are the main small-scale size reduction methods.
- Powders are classified as divided powders, bulk powders, dusting powders and others.
- They are flexible in dose but can be unpalatable, hygroscopic and unsuitable for unstable drugs.
Relevance to pharmacy practice
Powders are still dispensed in hospitals and community pharmacies. A pharmacist must know how to mix, divide and pack them accurately, especially potent drugs.
Every chapter in this subject builds on the one before it, so do not skip topics that look simple. Definitions, classifications and official examples are the parts that examiners return to most often, and a clear understanding here will also make later subjects such as pharmaceutics and pharmacology much easier to follow in the coming semesters.
Frequently asked questions
What is levigation?
Levigation is wetting a powder with a liquid, in which it is insoluble, to reduce its particle size on an ointment slab.
What are divided powders?
They are powders divided into individual doses, each wrapped separately for the patient.
What are the disadvantages of powders?
Powders may taste bad, are not suitable for unstable or hygroscopic drugs, and are less convenient to carry than tablets.
Quick revision checklist
Use this self-test after reading the chapter on powders. If you can do all of the following without looking at your notes, you are ready for the exam.
- I can explain: properties of powders
- I can explain: methods of size reduction
- I can explain: classification of powders
- I can explain: advantages and disadvantages
- I can explain: official powder preparations
Study and exam tips
Start by reading the chapter once for the overall idea, then revise powders using headings, definitions, classifications and examples. Short-answer questions in the university exam usually ask for definitions, advantages, disadvantages and examples, so write these in your own words and practise drawing tables and flow charts where the chapter has them.
For wider reading, standard textbooks and open resources such as the NCBI Bookshelf help you confirm terms and see more worked examples. Revise powders again a day later and again a week later, because spaced revision improves long-term memory.
This page is part of the General Pharmacy 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.
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