Q1. What is disintegration, and why is it important in tablet evaluation?
A:
Disintegration is the process by which a tablet breaks down into smaller fragments in a liquid medium to release its active ingredients. It is important because proper disintegration is a prerequisite for drug dissolution, absorption, and therapeutic effectiveness.

Q2. What is the standard apparatus used to test tablet disintegration?
A:
The USP Disintegration Apparatus is used, which consists of a basket rack assembly containing six open-ended tubes with a wire mesh at the bottom, immersed in a medium such as water or simulated gastric fluid.

Q3. What are the standard conditions for a disintegration test?
A:
For uncoated tablets, the test is conducted in water at 37 ± 2°C with a time limit of 15 minutes (varies depending on pharmacopoeial requirements). Coated tablets may have different limits based on the coating type.

Q4. How does disintegration differ from dissolution?
A:

• Disintegration: The process of breaking down a tablet into fragments.
• Dissolution: The process of dissolving the active ingredient into the surrounding medium after disintegration.

Q5. What is friability, and why is it tested in tablets?
A:
Friability measures the tendency of a tablet to break or crumble under mechanical stress. It ensures tablets can withstand handling during manufacturing, packaging, and transportation without significant damage.

Q6. What equipment is used to measure friability?
A:
The Roche Friabilator is used, where tablets are rotated at 25 rpm for 4 minutes (100 rotations) in a drum with baffles, and the weight loss is measured.

Q7. How is friability calculated, and what is the acceptance limit?
A:
Friability (%) is calculated as:

% friability = initial weight of tablets – final weight of tablets / initial weight of tablets multiplied by 100

Acceptance limit: Friability should be less than 1.0% for most tablets.

Q8. What factors can affect the friability of tablets?
A:

• Poor compression force during tableting.
• Inadequate binder in the formulation.
• High moisture content in granules.
• Rough handling during production or packaging.

Q9. How does coating influence disintegration and friability?
A:

• Disintegration: Film-coated tablets may take longer to disintegrate due to the barrier layer. Enteric-coated tablets disintegrate only in the intestinal fluid.
• Friability: Coating can improve friability by providing a protective layer, reducing the risk of chipping or cracking.

Q10. What is the difference between hardness and friability?
A:

• Hardness: Refers to the mechanical strength of a tablet to resist breaking under pressure.
• Friability: Measures the ability of a tablet to resist crumbling or chipping during handling.

Q11. What is the significance of disintegration time in immediate-release tablets?
A:
Disintegration time ensures that the drug is quickly available for absorption, providing a rapid onset of action, which is essential for immediate-release dosage forms.

Q12. Why are friability tests not conducted on all tablets?
A:
Friability tests are not typically conducted on lozenges or chewable tablets, as these dosage forms are designed to be deliberately broken apart during use.

Q13. How can friability be reduced during tablet manufacturing?
A:

• Increase compression force.
• Optimize the binder concentration in the formulation.
• Improve granule size and distribution.
• Ensure proper drying of granules to avoid excessive moisture.

Q14. What is the role of binders in disintegration and friability?
A:
Binders help improve tablet cohesion, reducing friability. However, excessive binder concentration may delay disintegration and reduce drug release rates.

Q15. What are some common disintegrants used in tablet formulations?
A:

• Starch: Acts by swelling in contact with water.
• Croscarmellose Sodium: Cross-linked polymer that swells rapidly.
• Sodium Starch Glycolate: Effective at low concentrations for rapid disintegration.