LACTITOL

Absorption

In healthy subjects under fed conditions, oral administration of 20 grams of lactitol resulted in a mean Tmax of 3.6 ± 1.2 hours, Cmax of 776 ± 253 ng/mL, and a mean AUC of 6,019 ± 1,771 ng*hr/mL.

Toxicity

The LD50 is 23 g/kg in mice and >30 g/kg in rats.
Experience with acute overdosage is limited, but is likely to involve significant gastrointestinal upset and diarrhea consistent with the pharmacologic profile of lactitol. Overdosage should be managed with symptomatic and supportive measures, where necessary.

Description

Lactitol (4-o-(|3-D-Galactopyranosyl)-D-glucitol) is a disaccharide sugar alcohol derived from lactose by reduction of its glucose moiety. Lactitol has not been found in nature. It is about 0.4 times as sweet as sucrose.
In vitro studies with galactosidase-containing enzyme preparations have demonstrated that lactitol is hydrolyzed only very slowly. In incubations with human intestinal biopsies, it has been shown that the human intestinal mucosa does not exhibit any significant dis accharidase activity with lactitol as a substrate. The hydrolytic activities towards lactitol and isomalt were only 1.3% of those towards lactose and isomaltulose, respectively. Corresponding exper iments with intestinal preparations of germ-free pigs and convention ally kept minipigs gave similar results. These observations indicate that lactitol is the most slowly digested disaccharide sugar alcohol. However, in vitro investigations with intestinal enzyme prepara tions provide only relative figures on hydrolysis rates. Experiments with humans and 14C-labeled lactitol during jejunal perfusion indi cate that lactitol is virtually not assimilated by the human small intestine. After passage through the small intestine, ingested lac titol reaches the bacterially colonized segments of the gut where intensive fermentation takes place. Short-chain fatty acids (acetate, propionate, butyrate) are the major fermentation end products which are subsequently further metabolized by the host.
Lactitol is slowly fermented in growing cultures by some strepto cocci, actinomyces and lactobacilli. When fed at 25% of the diet to rats that had been inoculated with Streptococcus mutans, lactitol was about equally as cariogenic as sorbitol and significantly less cariogenic than sucrose. Test candies and chocolates sweetened by lactitol are hypoacidogenic in humans tested by plaque pH telemetry. Boiled sweets made with 100% lactitol are rough in texture owing to crystallization, and caused some gastrointestinal upsets in human volunteers. Since lactitol has only one-third the sweetness of sucrose, sweets need an additional sweetening agent for palatability.

Chemical properties

Lactitol occurs as white orthorhombic crystals. It is odorless with a sweet taste that imparts a cooling sensation. It is available in powdered form and in a range of crystal sizes. The directly compressible form is a water-granulated product of microcrystalline aggregates.

The Uses of LACTITOL

Lactitol is listed as an excipient in some prescription drugs, such as Adderall. Lactitol is a sugar alcohol used as a replacement bulk sweetener for low calorie foods. It is also used medically as a laxative.

Background

Lactitol, also known as 4-β-D-galactopyranosyl-D-glucitol, is a sugar alcohol synthesized from lactose. It is used in food manufacturing as a nutritive sweetener and is approximately 35% as sweet as table sugar (i.e. sucrose). Clinically, lactitol has been investigated for use as an osmotic laxative and, along with other non-absorbable disaccharides such as lactulose, in the treatment of hepatic encephalopathy in patients with cirrhosis.
Pizensy, an oral lactitol powder for solution, was approved by the FDA for use in chronic idiopathic constipation in February 2020.

Indications

Lactitol is indicated for the treatment of chronic idiopathic constipation in adults.

Production Methods

Lactitol is produced by the catalytic hydrogenation of lactose.

Definition

ChEBI: Lactitol is a glycosyl alditol consisting of beta-D-galactopyranose and D-glucitol joined by a 1->4 glycosidic bond. It is used as a laxative, as an excipient, and as replacement bulk sweetener in some low-calorie foods. It has a role as a laxative, an excipient and a cathartic.

Pharmaceutical Applications

Lactitol is used as a noncariogenic replacement for sucrose. It is also used as a diluent in solid dosage forms.(1) A direct-compression form is available,(2,3) as is a direct-compression blend of lactose and lactitol. Lactitol is also used therapeutically in the treatment of hepatic encephalopathy and as a laxative.

Pharmacokinetics

Lactitol helps to facilitate bowel movements by drawing water into the gastrointestinal tract. The oral administration of lactitol may reduce the absorption of concomitant medications - other oral medications should be administered at least 2 hours before or 2 hours after lactitol.

Safety

Lactitol is regarded as a nontoxic and nonirritant substance. It is not fermented significantly in the mouth, and is not cariogenic.It is not absorbed in the small intestine, but is broken down by microflora in the large intestine, and is metabolized independently of insulin. In large doses it has a laxative effect; therapeutically, 10–20 g daily in a single oral dose is administered for this purpose.
LD50 (mouse, oral): >23 g/kg
LD50 (rat, oral): 30 g/kg

Metabolism

As it undergoes little-to-no systemic absorption, lactitol is unlikely to undergo any significant degree of metabolism.

storage

Lactitol as the monohydrate is nonhygroscopic and is stable under humid conditions. It is stable to heat and does not take part in the Maillard reaction. In acidic solution, lactitol slowly hydrolyzes to sorbitol and galactose. Lactitol is very resistant to microbiological breakdown and fermentation. Store in a well-closed container. When the compound is stored in an unopened container at 25°C and 60% relative humidity, a shelf-life in excess of 3 years is appropriate.

Regulatory Status

GRAS listed. Accepted for use as a food additive in Europe. Included in the Canadian List of Acceptable Non-medicinal Ingredients.