What is the consequence of using worn punches during tableting?

Using worn punches during tableting can lead to whiskering, which refers to the phenomenon of cracking and chipping of the tablet edges or surfaces. This occurs because worn punches may not provide a uniform compaction and may apply uneven forces during the compression of the powder blend. As a result, the mechanical integrity of the tablets is compromised, leading to defects such as cracks or chips on the tablet surfaces.

When punches wear out, they can create inconsistencies in tablet shape and density, causing weak spots in the tablet that are more susceptible to fracture during ejection from the die and handling. Whiskering is particularly problematic because it not only affects the appearance of the tablets but can also impact their stability and dissolution properties, potentially affecting drug release and overall efficacy.

In contrast, capping generally occurs when there is insufficient binding or the presence of air entrapment, mottling relates to uneven color distribution, and plasticizing refers to a change in material properties that is more associated with moisture content or specific processing conditions rather than due to punch wear. Thus, whiskering is the most relevant consequence of using worn punches in tablet manufacturing.