| Abstract: | Three types of crystalline lactose hydrates having melting points (MP) of 218°C, 195°C and 169°C were crystallised from 680 ml litre?1 ethanol solution with a lactose to solvent ratio of 1:14-1:24 at three pH values, ～ 4, 2.5 and 1.3. The three types were characterised on the basis of their optical rotation, phase transition and X-ray powder diffraction pattern. The samples with high and low MP were α-lactose hydrates whereas that with the intermediate MP (195°C) was a hydrated lactose containing both α- and β-forms. |
