Lactose: a definitive guide to polymorph determination

Lactose is a well-known molecule capable of forming a number of different polymorphs with varied chemical and physical properties. To date, no definitive guide for distinguishing between polymorphs using simple analytical techniques has been available. The information presented in this article aims to provide a conclusive guide for identifying the polymorphs of lactose and to successfully unravel years of contradictory research. Data have been collected on single phase polymorphs, prepared from an identical source, adopting the use of in situ and ex situ powder X-ray diffraction, CCD-Raman, FT-IR and (13)C-(1)H cross-polarisation magic angle spinning NMR (CP-MASNMR) spectroscopy, in order to provide simple methods to discriminate between the polymorphs.