Tablet Defects PDF

# **CONTENTS** - Introduction - Defects in Tablets - Capping and Lamination - Capping - Lamination - Causes and Corrective Actions - Air entrapment - Excessive pressure - Too rapid expansion of tablet upon ejection - Poor gr...

# **CONTENTS** - Introduction - Defects in Tablets - Capping and Lamination - Capping - Lamination - Causes and Corrective Actions - Air entrapment - Excessive pressure - Too rapid expansion of tablet upon ejection - Poor granulation - Punch cavity too deep - Punch tips worn - Lower punch set too low at tablet take-off - Tablet take-off bar set too high - Picking and Sticking - Causes and Corrective Actions - Excessive moisture - Presence of low-melting-point substances - Insufficient compaction force - Inadequate lubrication of granulation - Punch face condition - Poor embossing design - Mottling - Causes and Corrective Actions - High moisture content of granulation - Oversized granulation particles - Contamination of granulation - Double Impression - Causes and Corrective Actions - Rotation of punches - Dirt in Product (Black Specks) - Causes and Corrective Actions - Dust, dirt, or press lubrication in the granulation - Excessive or wrong press lubrication - Rubbing of feeder components - Chipping or Splitting - Causes and Corrective Actions - Poor surface finish on punch tips; worn punches and dies - Poor tooling design (e.g., sharp embossing or bisect lines) - Defects in sugar coated tablets - Defects in film coated tablets - Conclusion - References # **Introduction** - In the normal process of developing formulations and in the routine manufacture of tablets, various defects are observed. - Sometimes, the source of the problem or the defect is the formulation, the compression equipment, or a combination of the two. - Some defects are noticed immediately during manufacturing but others may be noticed during storage. # **Defects in Tablets** ## **Capping and Lamination** - **Capping** is defined as the partial or complete separation of the top or bottom crowns of a tablet from the main body of the tablet. - **Lamination** is the separation of a tablet into two or more distinct layers. - These processing problems are readily apparent immediately after compression or may occur hours or even days later. - Subjecting tablets to the friability test is the quickest way of revealing such problems. ## **Causes and Corrective Actions** - **Air entrapment** - Reduce press speed - Precompress granulation - Reduce quantity of fine particles in the granulation - Taper dies - Ensure that punch-to-die clearance is correct - **Excessive pressure** - Reduce tablet weight and/or increase its thickness within allowable tolerances - Adjust pressure - **Too rapid expansion of tablet upon ejection** - Taper dies - **Poor granulation** - Increase quantity of binder; use strong binder - **Excessively dry granulation** - Increase lubricant - **Excessive lubrication of granulation** - Decrease lubricant; blend all ingredients before adding lubricant - **Punch cavity too deep** - Use punches with less concave depth - **Punch tips worn** - Refurbish or replace punches - **Lower punch set too low at tablet take-off** - Set lower punch tip flush with top of die - **Tablet take-off bar set too high** - Adjust take-off bar ## **Picking and Sticking** - **Picking** refers to a tablet material being removed from the tablets surface by a punch. - It is of particular concern when punch tips have engraving or embossing. - Tablet materials adhering to punches can accumulate to the point of obliterating the tip design. - **Sticking** refers to a tablet material adhering to the die wall. - It results in the build up of material on punch faces. ## **Causes and Corrective Actions** - **Excessive moisture** - Check moisture content of granulation; drying - Check room humidity - **Presence of low-melting-point substances** - Dilution with higher-melting-point materials - **Insufficient compaction force** - Reduce tablet weight and/or increase its thickness within allowable tolerances - **Inadequate lubrication of granulation** - Check and/or adjust level of lubricant used - **Punch face condition: pits on punch faces and/or improper draft on embossing** - Try repolishing punch faces - Try chrome-plating of punch faces - **Poor embossing design** - Redesign embossing per TSM guidelines, or consult tooling supplier ## **Mottling** - Unequal distribution of color on a tablet, with light or dark areas standing out in an otherwise uniform surface. ## **Causes and Corrective Actions** - Drug whose color differs from the tablet excipients or a drug whose degradation products are colored. - Use of colorants - Migration of dyes to the surface of granulation during drying - Change the solvent system - Reduce the drying temperature - Grind to a small particle size - **High moisture content of granulation** - Dry granulation - **Oversized granulation particles** - Reduce particle size - **Contamination of granulation, usually by grease or oil** - Check oil seals on upper punch guides - Fit oil/dust caps to upper punches - Reduce lubrication of upper punches to an acceptable level - **Contamination of granulation from chutes or feed hoppers** - Clean and reset components correctly ## **Double Impression** - This problem is encountered with punches that have a monogram or other engraving on them. ## **Causes and Corrective Actions** - **Rotation of punches** - Adjust antiturning devices - Use keyed punches ## **Dirt in Product (Black Specks)** ## **Causes and Corrective Actions** - **Dust, dirt, or press lubrication in the granulation** - Clean press more frequently - **Excessive or wrong press lubrication** - Use proper punch dust caps - **Rubbing of feeder components** ## **Chipping or Splitting** ## **Causes and Corrective Actions** - **Poor surface finish on punch tips; worn punches and dies** - **Poor tooling design (e.g., sharp embossing or bisect lines)** - Polish punch tips; replace punches and dies # **Defects in sugar coated tablets** # **Defects in film coated tablets** # **Conclusion** # **References**