New paper from Ghent university. 

External lubrication is a highly valuable alternative lubrication method as it minimizes the negative impact on tablet properties encountered when using internal lubrication. In current study, experiments were performed with automated external lubrication systems implemented in a compaction simulator and rotary tablet press using three lubricants (magnesium stearate (MgSt), sodium stearyl fumarate (SSF) and glyceryl dibehenate (DBHG)).

In conclusion, the potential of external lubrication for implementation on production scale tableting equipment and during scale-up was demonstrated for multiple lubricants.

More information in the papers section.

You can also find related papers on externa lubrication:

•    Screening of lubricants towards their applicability for external lubrication
• ·  Effect of binder type and lubrication method on the binder efficacy for direct compression
• ·  Evaluation of an external lubrication system implemented in a compaction simulator

Lubricants are often required to minimize friction between a tablet surface and the die walls during the ejection phase of the compression cycle. In turn the reduced friction minimizes the wear of punches and dies and avoid that tablets are stressed and damaged when ejected from the die cavity. Besides decreasing the friction that has often been described as the true role of a lubricant, lubricants can also serve as anti-adherent and glidant.

To specifically solve sticking and flowability issues, other excipients should be used, such as talc and colloidal silicon dioxide, respectively. Lubricants are a key excipient category in solid formulations but they can also lead to loss of tablet breaking force as well as slow down of dissolution. In order to maintain ejections forces as low as possible while minimizing the negative impact on tablet hardness and dissol...