Selective crystallization of vitamin D3 for the preparation of novel conformational polymorphs with distinctive chemical stability

Abstract

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.