1. What are the common problems in tablet compression?
Tablet compression issues include capping, lamination, sticking, picking, weight variation, hardness variation, chipping, double impression, and mottling. These issues arise due to formulation, machine, or process parameters.
2. What is capping in tablet compression?
Capping occurs when the top or bottom of a tablet separates due to excessive air entrapment, over-compression, or unsuitable binder levels.
Remedy: Adjust compression force, optimize binder levels, and ensure proper granulation.
3. What is lamination in tablet compression?
Lamination is the separation of a tablet into layers due to improper bonding or air entrapment.
Remedy: Optimize the compression force and drying process.
4. What is sticking in tablet compression?
Sticking refers to powder or granules adhering to the punch faces.
Remedy: Use anti-adherents like talc and magnesium stearate or improve granule lubrication.
5. What is picking in tablet compression?
Picking involves material sticking to the punches’ engraving, causing surface defects.
Remedy: Polish punches and use suitable anti-adherent agents.
6. What causes weight variation in tablets?
Weight variation stems from inconsistent powder flow or granule size.
Remedy: Optimize flow properties and maintain consistent feed frame levels.
7. What is the solution for hardness variation?
Hardness variation occurs due to uneven granule distribution or inconsistent compression force.
Remedy: Calibrate compression machines and maintain uniform granule distribution.
8. How do you prevent chipping?
Chipping results from brittle formulations or incorrect punch alignment.
Remedy: Modify formulation to enhance elasticity and align punches properly.
9. What is double impression in tablet manufacturing?
Double impression happens when punches shift during rotation.
Remedy: Use non-rotating upper punches and adjust punch tightness.
10. What is mottling, and how is it fixed?
Mottling refers to uneven color distribution.
Remedy: Use uniform particle sizes and avoid dye migration.
11. What causes binding in tablet compression?
Binding occurs when excessive heat or pressure damages punches or dies.
Remedy: Adjust tooling and reduce operating temperatures.
12. How to avoid powder segregation during compression?
Segregation happens due to density differences.
Remedy: Use glidants and maintain uniform mixing.
13. What is friability, and how is it controlled?
Friability is the tablet's tendency to break under stress.
Remedy: Optimize binder concentration and ensure proper compaction.
14. Why does tablet sticking increase with moisture?
Moisture softens granules, causing them to adhere to punches.
Remedy: Use drying methods and moisture-resistant coatings.
15. What role does granule size play in compression?
Uneven granule size affects flow, weight uniformity, and hardness.
Remedy: Sieve granules to ensure uniformity.
16. How do you fix poor tablet dissolution?
Poor dissolution occurs due to improper formulation.
Remedy: Adjust disintegrants and optimize compression.
17. What causes tablet friability failures in tests?
Friability failure arises from low binder levels or over-lubrication.
Remedy: Adjust binder content and monitor lubrication.
18. What is the effect of over-lubrication on tablets?
Over-lubrication reduces binding efficiency.
Remedy: Minimize lubricant quantities.
19. How can punch wear affect compression?
Worn punches lead to defects like capping and picking.
Remedy: Regularly inspect and replace punches.
20. What role does machine speed play in defects?
High speed causes poor die filling or air entrapment.
Remedy: Reduce machine speed to improve process control.
21. What causes excessive heat during compression?
Friction between punches and dies generates heat.
Remedy: Lubricate tools and use temperature-resistant materials.
22. Why does tablet hardness fail under low compression?
Low compression produces weak bonds between particles.
Remedy: Increase compression force within limits.
23. What is the effect of improper punch alignment?
Misaligned punches cause chipping and double impression.
Remedy: Ensure alignment using precise calibration tools.
24. How do you troubleshoot uneven coating defects?
Uneven coating results from poor tablet surface or improper application.
Remedy: Improve surface finish and optimize coating parameters.
25. What are the key steps in resolving tablet defects?
Key steps include:
- Identifying root causes (formulation, equipment, or process).
- Adjusting formulation (binder, lubricant, or granule size).
- Optimizing machine parameters (speed, compression force).
- Regular maintenance of equipment.
