THE PHYSICAL MODIFICATION OF LACTOSE AND ITS THERMOANALYTICAL IDENTIFICATION

Using DSC, at least 6 different types of lactose may be distinguished. In addition to the known alpha- and beta-modifications, there are different dehydrated forms. Rapid dehydration yields the probably partly amorphous alpha(H)-type which can reversibly sorb water from the vapour phase. Amorphous lactose can be detected by its characteristic recrystallization peak. Due to the mutarotational state of lyophilized lactose solutions, powders of amorphous lactose with different glass transition temperatures and different recrystallization behaviour may be produced.