Solid Oral Dosage Forms Flashcards
Define tablets
Compressed powders and/or granules
List 5 advantages of solid oral dosage forms
- Physical and Chemical stability
- Competitive unit production costs
- Palatability of administration
- Can accurately administer small and large drug doses
- Can modify release patterns if desired
List 3 limitations
- Swallowing Difficulties for children and unconsious parents
- Sense of bitter taste
- Drugs that have a low water solubility have difficulty forming compressed tablets
Define excipients
Inactive ingredients used as carriers to deliver the API in the correct way
Outline the role of a diluent (filler) and provide 2 common examples
- Provides sufficient bulk volume which makes it compressible
- Sugars (sucrose, mannitol, dextrose), microcrystalline cellulose
Outline the role of a binder and provide 3 common examples
- Holds the powder together to form granules
- Sugars
- Natural polymers (e.g. gums – tragacanth, acacia, gelatine)
- Synthetic polymers(e.g. PVP, cellulose, Eudragit, HPMC)
Outline the role of a super-disintegrant and provide 3 common examples with there MOA
Improves efficiency of disintegration in the GI
1.** Modified starches from potatoes**
- e.g. sodium carbomexthly starch
- MOA: rapid and extensive swelling straight after water absorption.
2. **cross-linked PVP **
- e.g. crospovidone
- MOA: water wicking and swelling
3. **Modified cellulose **
- Ac-di-sol, nymcel
- MOA: wicking and swelling and minimal gelling
Outline 2 pros and cons for super-disintegrants
Pros:
1. no lumps formed during disintegration
2. effective in lower concentrations
Cons:
1. more hydroscopic
2. some are anionic
Outline the role of lubricants and 2 examples
Reduce friction between granule and die wall during compression and ejection
1. Magnesium Stearate - a hydrophobic lubricant
- A decrease in disintegration time
- An increase in dissolution rate
2. Polyetheylene gycol -
Outline the role of glidants and provide 2 examples
Improves the flow of granules
1. Starch
2. Fumed silicon dioxide
Outline the mechanism of swelling, wicking/capillary action, deformation and release of gases - ways in which disintegrants break up tablets
- The disintegrant absorbs water,* enlarges omni-directionally, tablet matrix breaks apart, particles are released*
- Disintegrant absorbs water –> ruptures the interparticulate bonds –> tablet breaks apart
- Disintegrants absorb water and change shape
Outline the parameters that affect powder flow
- The particle size
- Small particles resist powder flow
- Large particles - not good
- optical size - slides over one another - Particle Size Distribution
- should have no more than 20% fine particles - Particle shape
- Spherical smooth structure is optimal - Density and Porosity
- Moisture of powder
- less moisture means less adhesion
Outline the direct compression method and list its pros and cons
Method: Ingredients mixed to form a uniform powder in a tubular mixer then the powder is compressed to form tablets
Pros:
- fewer steps involved
- no solvent or heat required
Cons:
- softer tablets produced
- expensive excipients
- Issues with powder flow
List the pros and cons for wet granulation method
Pros:
- Useful for low conc. of API
- drug is bound into granules = good homogeneity
- good tablet appearance
- reduced segregation during processing
Cons:
- more costly, several steps
- heat and solvent required
List the pros and cons for dry granulation
Pros:
- Works well for drugs that do not compress well with wet granulation
- No solvent or heat required
- Used for moisture-sensitive drugs
Cons:
- Possible segregation during processing
- Special equipment required
- Poorer appearance of tablets
