There are a lot of common tablet problems arise during compression and coating. Some of them discuss below-
Mottling
Definition: 'Mottling' is a tablet problem where unequal distribution of color occurs on a tablet, with light or dark spots standing out in an otherwise uniform surface.
Reasons:
- A colored drug used along with colorless or white-colored excipients.
- A dye migrates to the surface of granulation while drying.
- Improper mixing of dye, especially during 'Direct Compression'.
- Improper mixing of a colored binder solution.
Remedies:
- Use appropriate colorants.
- Use a smaller particle size of API and Excipients.
- Mix properly and reduce size if it is of a larger size to prevent segregation.
Color Variation during coating
Color variation is also a tablet problem usually arise during coating.
Reasons:
- Improper mixing
- Uneven spray pattern
- Insufficient coating
Remedies:
- Proper mixing
- Uniform spray
- Optimize coating formulation
Orange Peel
A tablet problem which result a bumpy or orange peel effect on coating before drying.
Reasons:
- Impaired spreading by rapid rate of drying
- High viscosity of solution
Remedies:
- Thinning of coating solution