Abstract: The invention relates to a process for the separation of lactulose from a mixture of lactulose and lactose in the presence of a weak acid capable of reversibly forming a complex with lactulose, by using an electrodialysis equipment including an anode and a cathode compartment separated by a plurality of parallel compartments comprising alternating diluate and concentrate compartments, wherein adjacent compartments are separated from each other by permselective membranes; which process is characterized by:(a) continuously passing an alkaline aqueous solution of lactulose, lactose and said complex forming weak acid through the diluate compartments, each diluate compartment being bound by a bipolar membrane at its lateral side facing the cathode and at its opposite lateral side by an anion exchange membrane, separating said compartment from its adjacent concentrate compartment;(b) continuously passing a carrier fluid through the concentrate compartments, each concentrate compartment being bound at its lateral si

Abstract: The invention relates to a method of preparing solid forms of administration of lactulose by evaporating lactulose syrup to a water content of at most 10%, preferably 2 to 6%, cooling the thick, evaporated syrup, grinding and sieving, or breaking the solid product.

Abstract: The invention relates to a new method of preparing lactulose by basic isomerization of lactose. According to the invention the reaction mixture is treated with hydrogen peroxide or sodium chlorite to obtain lactulose of an acceptable color for a pharmaceutical product.Preferably 0.5-5 g of hydrogen peroxide are used per kg of lactose.1H.sub.2 O.