Excipients for immediate-release tablets Flashcards
What is an IR tablet?
Uncoated (mostly) / uncoated tablet, with a purpose to have the a rapid rate of disintegration
What is the time for dissolution that complies with the BP?
75% in 45 minutes
Which excipients are in an IR tablet that influence the tablet formation?
Filler Binder Lubricant Anti-adherent Glidant
Which excipients in IR influence the drug release & absorption?
Disintegrant
Dissolution enhancer
Absorption enhancer
Which excipients influence organoleptic enhancement?
Coating
Colourant
Flavouring
What are the acceptance criterias for IR tablets?
Must past Stage 1/2/3
What is the function of the filler/dilutent?
Makes tablets more than 50mg easier for handling
What is the function of the binder?
Adhesive
Increases compactability and mechanical strength
What is the function of a disintegrant?
Breaks the tablet up into smaller particles (when it enters the body)
What is the function of a lubricant?
Reduces friction
What is the function of an anti-adherent?
Prevents adhesion to punches (during compaction process)
What is the function of the glidant?
Improves powder flowability
What is the function of the coating?
Masks taste
Improves ease of swallowing
Reduces friability
Improves stability
What is the function of the colourant?
Tablet identification
In tablet core or coating
Printing ink
What is the function of flavouring?
Enhance test
Not usually used for tablets that are swallowed
What is the common lubricant used in paracetamol?
Stearic acid which can function as anti-adherent and glidant. (hydrophobic)
What is the common binder used in paracetamol?
Polyvinyl pyrrolidone (PVP)
What is a caplet?
An elongated tablet
What binder is obtained from animals?
Gelatin
What are some properties of gelatin?
semi-synthetic, odourless, soluble in water
What are the two types of disintergants?
Traditional and superdisintegrants
What is a traditional disintegrant?
Polymers swell in 2D upon hydration
What is a superdisintegrant?
Cross-linked polymers swell in 3D upon hydration,much more effective for this matter
What is the purpose of disintegrant?
Increase the surface area
The larger the surface area, the ….. the dissolution.
Quicker
What are the mechanism of disintegration (6)?
1) Swelling
2) Wicking
3) Strain recovery
4) Heat of interaction (wetting)
5) Interruption of bonding forces
6) Repulsion
What is wicking?
Hydrophillic polymers create hydrophillic conduits
*water diffuses through pores, creates a hydrophillic passage causing water to come through, therein starting the swelling process
What is wicking?
Hydrophillic polymers create hydrophillic conduits
*water diffuses through pores, creates a hydrophillic passage causing water to come through, therein starting the swelling process
What is strain recovery?
Particles deform elastically during tablet formation and become interlocked with potential energy.
Water infiltration into tablet causes particles to regain original shape.
What is heat of interaction? (wetting)
Heat released during particle interaction with water
What is the interruption of bonding forces?
Interlocking particles, solid bridges, bonds weakened in aqueous environment (Bridge washed away by water)
What is repulsion?
Electrostatic repulsion pushes particles apart
What is the in vitro disintegration time for Paracetamol effervescent tablets?
<5
What is effervescent disintegration? (Sodium hydrogen carbonate)
Gas generation, of CO2 when put in water, gas forces the tablets to break
What is the point of IR?
to increase rate of dsintegration
