Tablets G Flashcards
(30 cards)
What are tablets made by?
Compressing a particulate solid between two punches in a die.
List three essential attributes of tablet formulation.
- Rapid flow into die, 2. Cohesion under pressure, 3. Easy removal from press.
Why is flowability important in tablet manufacture?
Ensures smooth movement from hopper to die, avoiding issues like arching or bridging.
What is granulation?
Process of enlarging particle size to improve flowability, compressibility, and bulk density.
What are the main types of tablet manufacturing?
Wet granulation, dry granulation, and direct compression.
What are diluents used for?
To add bulk to the formulation and ensure tablets are of reasonable size.
Give an example of a common diluent.
Lactose monohydrate – inexpensive, inert, widely used.
What are binders?
Adhesives that bind powder in granulation to give strength during compression.
What is friability?
The tendency of a tablet to crumble, indicating mechanical strength.
Name one common binder and its property.
PVP – soluble in water and organic solvents.
What are disintegrants used for?
To promote tablet breakup and improve drug dissolution.
How do disintegrants work?
By swelling and capillary action.
What are lubricants used for?
To prevent adherence to punches and dies during compression.
Why are magnesium stearate and sodium lauryl sulphate used together?
Magnesium stearate is hydrophobic; SLS adds wetting to improve disintegration.
What are glidants?
Substances that improve flow by reducing inter-particle friction.
Give an example of a glidant.
Colloidal silica – excellent glidant.
Advantages of wet granulation?
Improved flow, cohesion, reduced dust, better homogeneity.
Disadvantages of wet granulation?
Sensitive to drying time/temperature; not for hydrolysable/thermolabile drugs.
What is intergranular migration?
Solutes move between granules during drying, causing drug maldistribution.
What is intragranular migration?
Solutes move within granules to their periphery during drying.
Advantages of direct compression?
Simple, economical, fast, avoids water/heat exposure.
Disadvantages of direct compression?
Not suitable for low potency drugs, risk of segregation, expensive excipients.
What are DC diluents?
Physically modified excipients for direct compression with good flow and compressibility.
Example of a DC diluent and issue?
Spray-dried lactose – flows well but forms weak tablets.
