Tablets Flashcards
What are the requirements of the tablet machine?
Uniform flow of powder No segregation Die cavity uniformly filled Powder compressibility Lubricants
What is granulation and the 7 benefits
Build up of small particles into larger aggregates with aid of bonding agent or mechanical force
- spherical and free flowing particles
- uniformed size distribution
- Improved flow
- reduced segregation
- volume dispensing
- improved compression
- binder introduction
What are the 3 stages of wet granulation?
Perpendicular - liquid bridges
Funicular- bridges with localised areas of void space
Capillary - interstitial pores completely filled with binder medium
What are the advantages of spray granulation?
One step procedure
Equipment applicable for different unit operations
What are the disadvantages of wet granulation?
Processing conditions derived from trial and error
Multi stage process (expensive)
Incompatibilities with drug
What are the uses of dry granulation?
Moisture sensitive material
Heat sensitive material
Needs less equipment
What are the disadvantages of dry granulation?
Granules with low porosity
Dust
Special equipment required
What requirements do direct compression excipients require?
Good flow Compression properties Particle size distribution similar to drug High bulk density Physically and chemically stable Chemically inert
What are the advantages and disadvantages of direct compression?
Ad
Least handling of material
Eliminates heat and moisture
Economical
Disad
Can’t be applied to low or high dose tablets
Poser segregation
Dose uniformity problems
What are the advantages of tablets?
Accuracy in dosing
Convenient administration and patient compliance
Stability
Ease of manufacture
What are fillers? Give examples of soluble and insoluble ones
Bulk of tablet they make tablet weight practical for patient
Soluble - sucrose, lactose, dextrose
Insoluble - calcium sulphate, phosphate and carbonate, starch, microcrystalline cellulose
What are binders and give examples?
Provide cohesiveness so uniformity, compression and hardness of tablet achieved
Sucrose, methycellulose and ethyl cellulose
What are lubricants and give examples?
Reduce friction between powder particles and die during compression and ejection
Examples: magnesium stearate, sodium stearate, PEG6000
What are glidants?
Improve flow of powder
What are disintegrants and how do they work?
De aggregation of compacted tablets
Swell, hydrate and change volume this disrupts intra particle cohesive forces that hold tablet together
