Development of agglomerated crystals of ascorbic acid by the spherical crystallization technique for direct tableting, and evaluation of their compactibilities

Abstract

Spherically agglomerated crystals of ascorbic acid for direct tableting were successfully prepared by the spherical crystallization technique. This agglomeration dramatically improved the micromeritic and compaction properties of the original ascorbic acid crystals. The dominating mechanisms that improved compaction properties of the spherically agglomerated crystals depended on their fragmentation and plastic deformation during compaction. Support for this mechanism existed because the compacted agglomerated crystals had higher stress relaxation and lower elastic recovery than the original crystals. Spherically agglomerated crystals were tableted directly without capping by using a single-punch tableting machine under dynamic compaction, although the tensile strength of tablets with spherically agglomerated crystals decreased when the compression speed increased.