Chemical Properties
White Powder
Originator
Duphalac,Philips-Duphar,UK,1969
Uses
A keto analogue of lactose.
Uses
Lactulose is is a synthetic, non-digestible sugar used in the treatment of chronic constipation; laxative.
Uses
pharmaceutical excipient
Definition
ChEBI: A synthetic galactosylfructose disaccharide used in the treatment of constipation and hepatic encephalopathy.
Indications
Osmotic laxatives (e.g., lactulose, sorbitol) are poorly
absorbed or nonabsorbable compounds that draw additional
fluid into the GI tract. Lumen osmolality increases,
and fluid movement occurs secondary to osmotic
pressure. Lactulose is a synthetic disaccharide
that is poorly absorbed from the GI tract, since no
mammalian enzyme is capable of hydrolyzing it to its
monosaccharide components. It therefore reaches the
colon unchanged and is metabolized by colonic bacteria
to lactic acid and to small quantities of formic and acetic
acids.
Manufacturing Process
105 g of lactose monohydrate were dissolved in 500 ml of water. 48 g of
NaAlO2 was dissolved in 100 ml of water and was then added to the lactose
solution. The mixture was then diluted to one liter to provide a pH of 11.5.
The reactant concentrations of 48 g of sodium aluminate and 105 g of lactose
are equivalent to a mol ratio of two mols of aluminate to one mol of lactose.
The mixture was then heated to 50°C and 100 ml aliquots were removed at
periodic intervals to determine the level of conversion. The reaction was
terminated after three hours by adding sufficient 30% HCl to lower the pH to
4.2. The pH was then raised to neutrality, i.e., 6.5 to 7.0, with ammonium
hydroxide so as to completely precipitate insoluble aluminum hydroxide. The
precipitate was then removed by vacuum filtration and the filtrate was
analyzed for the presence of ketose sugar by chromatographic analysis. The
chromatographic analysis of the filtrate confirmed that the main component of
the filtrate was lactulose and not the monosaccharide ketose sugar, fructose.
Brand name
Cephulac (Sanofi
Aventis); Chronulac (Sanofi Aventis); Constulose (Acta-
vis); Duphalac (Solvay Pharmaceuticals); Enulose (Actavis); Evalose (Teva); Generlac (Morton Grove); Heptalac
(Teva); Laxilose (Technilab); Portalac (Solvay Pharma-
ceuticals).
Therapeutic Function
Laxative
Clinical Use
Lactulose is used in the
treatment of hepatic encephalopathy.
Side effects
Since lactulose does contain galactose, it is contraindicated
in patients who require a galactose-free
diet. Metabolism of lactulose by intestinal bacteria may
result in increased formation of intraluminal gas and
abdominal distention.
Veterinary Drugs and Treatments
The primary use of lactulose in veterinary medicine is to reduce
ammonia blood levels in the prevention and treatment of hepatic
encephalopathy (portal-systemic encephalopathy; PSE) in small
animals and pet birds. It is also used as a laxative in small animals.
Purification Methods
Crystallise lactulose from MeOH or 50% MeOH. It mutarotates from [] D 20 -11.9o to –50.7o (c 1, H2O). [Montgomery & Hudson J Am Chem Soc 32 2101, 2104 1930, Beilstein 17 III/IV 3094, 17/7 V 214.] NMR in Me2SO at 24o shows 0% -pyranose, 27% -pyranose, 20% -furanose and 52% -furanose fforms [Angyal Adv Carbohydr Chem 42 15 1984].
