Selective crystallization of vitamin D3for the preparation of novel conformational polymorphs with distinctive chemical stability

A new conformational polymorph of VD3 containing a pure α conformer was prepared and fully characterized. Chemical stability and hygroscopicity are compared with the marketed solid-state form (form A, two conformers α/β, 1 : 1). The results indicate that crystallization of VD3 needs to be controlled to avoid the unstable polymorph.