ELASTIC RECOVERY

Are your formulations or APIs prone to capping?

For most materials, tablet dimensions change between the tablet being compressed and it being ejected. Occasionally, contraction of the tablet is observed but typically expansion occurs. This is termed elastic recovery. Excessive elastic recovery is associated with manufacturing defects, particularly capping. Such defects require the slowing of tablet presses which can have a massive impact on productivity. Checking for elastic recovery during development and manufacture can help identify materials or formulations at risk capping and other defects. We can minimise elastic recovery by selecting the right excipients.

Elastic Recovery Cap - Excessive elastic recovery is associated with manufacturing defects, particularly capping
Elastic Recovery Cap - Excessive elastic recovery is associated with manufacturing defects, particularly capping

ELASTIC RECOVERY AND CAPPING

During ejection, the tablet is pushed out of the die. As the tablet emerges, the section of the tablet outside the die undergoes elastic recovery and expands. The section of the tablet still within the die remains constrained and unable to expand. As a result, shear stress can build up in the tablet leading to capping and lamination. Choosing the right excipients will help strengthen inter-particulate bonds allowing a formulation to withstand elastic expansion.

Diagram of Radial Expansion

THE GAMLEN DASHBOARD

The Gamlen Dashboard software automatically calculates elastic recovery for each tablet and allows the user to compare the elastic recovery profiles of different formulations. Using the Gamlen D-series analysis suite all measurements and calculations are automated, so the profiles are generated with minimal user input.

Elastic Recover Profile Graph - showing three quarters in yellow and one quarter in green
Software Graphs Key - showing good in green, borderline in yellow and poor in red