Capping in Tablet Production: Causes, Prevention, and Production Optimization

Tablet manufacturing demands precision, expertise, and the right technology. Solids Development is here to support you in optimizing your tableting processes.

A common issue encountered in tablet production is known as „capping.“

What is Capping?

Capping occurs when a breakage appears at the top of the tablet, causing the top part to separate from the rest of the tablet. This is a critical quality issue and can lead to the loss of whole production batches, especially when it comes to coating.

Causes of Capping

– Entrapped Air: Air can become trapped within the tablet during the compression phase, resulting in capping.

-Over compression: too high forces causing too high elastic deformation

-lack of bonding capacity in the power combined with too low bulk density

– Too high tableting speeds leading to short rearrangement times for the particles of the powder

– Fine Particle Agglomeration: Accumulation of fine particles within the powder can also lead to this defect.

Strategies to Prevent Capping

  1. Adjusting Press Speed: Reducing speed can help minimize entrapped air.
  2. use and or adjust pre compaction force, or even add a 3rd compaction.
  3. change the press zone / immersion depth of the upper punch
  4. Increased Dwell Time: This allows the tablet more time to form and solidify properly.
  5. Formulation Review: The right mix and consistency of the powder are crucial. Optimization of the granulation process can also have an big impact on tablet properties.


Capping can have several root causes, sometimes these are also combined and is challenging to solve. Profound experience and expertise are needed to find a lasting solution.

At Solids Development Consult, we provide comprehensive solutions to optimize your tableting processes. With the right strategies and technologies, you can ensure the quality of your tablets and minimize production losses.