Abstract/Summary

A new crystalline form of αβ-D-lactose (C12H22O11, Z' = 2) has been prepared by rapid drying of an approximately 40 % w/v syrup of D-lactose. Initially identified from its novel powder X-ray diffraction pattern, the monoclinic crystal structure was solved from a microcrystal recovered from the generally polycrystalline, mixed-phase residue obtained at the end of the drying step. This is the second crystalline form of αβ-D-lactose to be identified and it has a high degree of structural 3D similarity to the previously identified triclinic form.