Three polymorphs, a-, b- and d-mannitol, and mannitol hemi-hydrate, a pseudo-polymorphic form formed during freeze-drying, have been described in literature (Burger et al., 2000). Burger et al. (2000) evaluated the compaction properties of these three polymorphs since the crystallographic and thermodynamic properties of polymorphs vary which can affect their compaction behavior. They reported on superior compressibility and tablet-ability of the d-polymorph in comparison to the a- and b-polymorphs of mannitol. More recently, Wagner et al. (2015) confirmed this result as they found an improved tabletability of d-mannitol granules after roller compaction.