X-ray Computed Tomography for Evaluation of Density Gradient Formation during the Compaction of Spray-Dried Granules

X‐ray computed tomography was used to quantify the internal structure of compacts made from poly(vinyl alcohol)‐containing spray‐dried agglomerates at specific levels of humidity. High humidities increased the average density but decreased the uniformity of the density distribution. Lower levels of humidity generally produced more diffuse high density zones. Internal uniformity is superior at lower humidities where agglomerate fracture is more common than gradual agglomerate deformation. SEM has been used to determine zone‐specific agglomerate behavior at 0% and 98% relative humidity. These results can be used to connect gradient development to compaction curve behavior.