The Importance Of Tablet Density Uniformity

Many common tableting problems, like poor friability and capping, stem from density variation within the finished tablet. Achieving uniform density is key, which means understanding the stages of powder compaction—from particle rearrangement and de-aeration to deformation and bonding—are critical.

Tablet proportions and design play a major role in density uniformity. For instance, a tablet that is too thin can restrict de-aeration, trapping air and leading to a soft center and over-compressed, hard edges, a condition that can cause lamination. Similarly, the cup profile and overall tablet size affect air dissipation. Larger tablets require more dwell time to expel air, which scales cubically with volume. Utilizing techniques like pre-compression and optimizing tip clearances can help. Finally, modern methods like CT scanning offer a non-destructive way to visualize a tablet's internal structure, identifying voids, cracks, delamination, and density inconsistencies to diagnose and fix tableting failures.

To learn more about how to optimize tablet and tool design to avoid these issues, access the full article.