Does the punch shape used to characterise compaction behaviour have to match that used in production?

At Gamlen we are often asked whether the compaction data from our instruments is useful for predicting the behaviour of formulations that are compacted with different shaped punches in production. This fascinating publication from some of our valued customers at Sawai Pharmaceuticals investigates this exact question. Which is why we’ve selected it as our first ever Paper of the Month.

  • The aim was to examine the usefulness of Gamlen data when developing commercial scale drug formulations.
  • Four formulations with different levels of lubricant were prepared.
  • Tableting properties measured on the Gamlen were compared with those of tablets produced on an industrial tableting machine (Fette)
  • Punches of various shapes were used on the Fette while only flat-faced cylindrical tablets were produced on the Gamlen.
  • Ejection stress values measured on the Gamlen were found to predict the likelihood of sticking at full scale.
  • Tensile fracture stress (TFS) measurements from the Gamlen paralleled those from the rotary tablet press.


“The GAMLEN correctly predicted the actual tableting results for all punch shapes. With punches that were more likely to cause tableting failure, our system predicted the effects of lubricant quantity in the tablet formulation and the occurrence of sticking in the rotary tableting machine.”

Mode Template Graph to show TFS and Ejection Stress