Twinning
It is a tablet coating defect, where 2 or 3 tablets stick together like twin baby.
Causes
- High spray rate
- Large droplet
- Low pan speed
- Inappropriate table shape
- Improper drying
Remedies
- Reduce spray rate
- High atomization
- Increase pan speed
- Select correct table shape
- Proper drying
Blistering
Blistering of a coating surface occurs when the film becomes detached from the tablet’s substrate.
Causes
- High temperature during spraying and drying
Remedies
- Operate at mild drying conditions
Picking
Picking is a coating problem where a part of the film sticks to the pan resulting to some of the tablet pieces being detached from the core.
Causes
- High spray rate
- Low pan speed
- Inadequate drying
- Over-wetting of tablets
Remedies
- Proper drying process
- Low spray rate
- Optimum pan speed
- Increase viscosity of coating solution
