Greco Lecture 4: Excipients Flashcards
Define what powder means in dosage form?
A formulation in which a drug powder has been mixed with other powdered excipients to produce the final product
What can a powder form in dosage form as a precursor?
- Directly (powder compressed to form a tablet)
2. Indirectly (via granules)
What are granules used for in dosage form and as a precursor?
- Granules are powder particles that are aggregated to form a larger particle
- Granules are used as an intermediate for tablet manufacturing
What are the advantages of powders and granules against tablets, capsules, liquids preparations?
- More stable than liquid
- Convenient for large doses (1 to 5g)
- Higher dissolution rate than capsules or tablets
What are the disadvantages of powders and granules against tablets, capsules, liquids preparations?
- Less convenient to carry than tablets and capsules
- Difficult to mask unpleasant taste
- Not suitable for administration of potent drugs
- Not suitable for drugs inactivate in the stomach or that can cause stomach/irritation
How are powders used orally in pharmaceutical use?
- Bulk powders or granules for internal use
(effervescent health salts) - Divided powders or granules (single prep)
What are the other administration routes of powders and granules?
- Dusting powders for external use
- Insufflation (ear/nose/throat)
- Antibiotic syrups to be reconstituted before use
- Powders for reconstitution into injections
- Dry powder inhalers
How do you know when oral powders comply with uniformity of content? When do you know if it passes or fails the test?
- When you take a tablet and they are within the region of 85 to 115 percent of the average content
- If three tablets are outside the region of 85 to 115 percent then it fails the test
- If one tablet is outside the region of 75 to 125 percent then it fails.
Why are tablets the most suitable drug dose in terms of manufacturing?
- Easy to scale up
- Versatile machinery
- More stable than liquid
Why are tablets the most suitable drug dose in terms of patients?
- Accurate dosage
- Easy to carry
- Easy to use
- Depending on the pharmacological requirements depends on how much is release
What are excipients?
- Chemically inert compounds that are added to pharmaceutical dosages to improve their characteristics
- May affect bioavailability
What are fillers (diluents) ? And give an example of some?
- They provide the tablet with the necessary bulk so that it can be taken in.
- Water soluble: Lactose and Glucose
- Water insoluble: Cellulose
What are binders and give an example of some?
- They allow the individual components of the tablet to bind together so that it can handle any mechanical stress
- Essentially prevents the tablet from falling apart
- Solution binder: Starch, sucrose and gelatin
- Dry binder: microcrystalline cellulose
What are glidants and give an example of one?
- They help improve the flowability of a powder by reducing friction between particles
- Example: Colloidial silica (0.1 to 0.5% w/w)
What are lubricants and give an example of one?
- They reduce the friction between the tablet and the die (the equipment with a hole that has a pit)
- Example: Magnesium Sterate at a concentration of 1%
What can too much magnesium sterate do to a tablet?
- Increases the wetability of the tablet too much which increases it’s lipophilic properties
- Leads to water not being able to penetrate the tablet which leads to tablet not being able to be broken by the body
- Can also cause the tablet to crumble as it can interfere with particle to particle interactions
What is a disintegrate and how does it work?
- Used to allow the tablet to break up and be absorbed
2. Absorbs water which causes it to swell and break up into granules or aggregates
What do effervescent tablets have in them to work especially?
A disintegrate known as carbonate to break up and react with water
What are colourants, sorbents and flavouring used for as excipients?
- Colourants: colours the tablet in a different colour which can allow you to identify one from the other (helpful in contraceptive pills)
- Sorbents: powder that absorbs water and still remains as a powder
- Flavouring agents: Helps make the tablet taste better, important for chewable tablets
