Common Tablet Manufacturing Defects in Pharma | Part-2
Mottling
Uneven distribution of color or pigmentation on the tablet surface.
Causes of Mottling:
- Colorants are not thoroughly blended ( mixed ).
- Chemical interactions between components can cause color variations.
- Insufficient drying.
Remedies for Mottling:
- Use appropriate blending techniques.
- Compatibility of colorants with other ingredients.
- Perform proper drying.
Flashing
It presents as a thin, unwanted edge around the perimeter of a tablet.
Causes of Flashing:
- Excess amount of tablet material in the die cavity.
- The powder fails to uniformly occupy the entire die cavity.
- Upper and lower punches are misaligned.
Remedies for Flashing:
- Use reliable feeding systems.
- Proper alignment of punchs.
Chipping
Breakage of tablet edges, resulting in small chips or fragments.
Causes of Chipping:
- Lack sufficient hardness.
- Tablets with high friability tend to chip.
- Tablets with sharp edges or corners.
- Inadequate lubrication between powder and punches.
Remedies for Chipping”
- Optimize the compression force.
- Round the edges and corners.
- Adequate lubrication between powder and punches.
Cracking
Visible cracks or fissures on the tablet surface.
Causes of Cracking:
- Excessive compression force.
- Binder isn’t good for sufficient strength.
- Powder isn’t lubricated.
Remedies for Cracking:
- Adjust the compression force.
- Optimize the concentration and type of binder.
- Appropriate lubricant is used.
Double Impression
Presence of two or more imprints on a single tablet.
Causes of Double Impression:
- Punches are not properly aligned.
- Rotation of lower punches is not controlled.
Remedies for Double Impression:
- Punches should be aligned.
- Ensure correct assembly and positioning of the punches.
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