The application of sorbitol powder in the pharmaceutical field

Medical applications

Laxative

As is the case with other sugar alcohols, foods containing sorbitol can cause gastrointestinal distress. Sorbitol can be used as a laxative when taken orally or as an enema.[6] Sorbitol works as a laxative by drawing water into the large intestine, stimulating bowel movements.[6][15] Sorbitol has been determined safe for use by the elderly, although it is not recommended without the advice of a physician.[6][16]

Sorbitol is commonly used orally as a one-time dose of 30–150 millilitres (1.1–5.3 imp fl oz; 1.0–5.1 US fl oz) 70% solution.[6] It may also be used as a one-time rectal enema.[6]

Other medical applications

Sorbitol is used in bacterial culture media to distinguish the pathogenic Escherichia coli O157:H7 from most other strains of E. coli, because it is usually unable to ferment sorbitol, unlike 93% of known E. coli strains.[17]

A treatment for hyperkalaemia (elevated blood potassium) uses sorbitol and the ion-exchange resin sodium polystyrene sulfonate (tradename Kayexalate).[18] The resin exchanges sodium ions for potassium ions in the bowel, while sorbitol helps to eliminate it. In 2010, the U.S. FDA issued a warning of increased risk for gastrointestinal necrosis with this combination.[19]

Sorbitol is also used in the manufacture of softgel capsules to store single doses of liquid medicines.[20]

Health care, food, and cosmetic uses

Sorbitol often is used in modern cosmetics as a humectant and thickener.[21] It is also used in mouthwash and toothpaste. Some transparent gels can be made only with sorbitol, because of its high refractive index.

Sorbitol is used as a cryoprotectant additive (mixed with sucrose and sodium polyphosphates) in the manufacture of surimi, a processed fish paste.[22] It is also used as a humectant in some cigarettes.[23]

Beyond its use as a sugar substitute in reduced-sugar foods, sorbitol is also used as a humectant in cookies and low-moisture foods like peanut butter and fruit preserves.[24] In baking, it is also valuable because it acts as a plasticizer, and slows down the staling process.[24]

Miscellaneous uses

A mixture of sorbitol and potassium nitrate has found some success as an amateur solid rocket fuel. It has similiar performance to sucrose-based rocket candy, but is easier to cast, less hygroscopic and does not caramelize.[25]

Sorbitol is identified as a potential key chemical intermediate[26] for production of fuels from biomass resources. Carbohydrate fractions in biomass such as cellulose undergo sequential hydrolysis and hydrogenation in the presence of metal catalysts to produce sorbitol.[27] Complete reduction of sorbitol opens the way to alkanes, such as hexane, which can be used as a biofuel. Hydrogen required for this reaction can be produced by aqueous phase catalytic reforming of sorbitol.[28]

19 C₆H₁₄O₆ → 13 C₆H₁₄ + 36 CO₂ + 42 H₂O

The above chemical reaction is exothermic, and 1.5 moles of sorbitol generate approximately 1 mole of hexane. When hydrogen is co-fed, no carbon dioxide is produced.

Sorbitol based polyols are used in the production of polyurethane foam for the construction industry.

It is also added after electroporation of yeasts in transformation protocols, allowing the cells to recover by raising the osmolarity of the medium.

Medical importance

Aldose reductase is the first enzyme in the sorbitol-aldose reductase pathway[29] responsible for the reduction of glucose to sorbitol, as well as the reduction of galactose to galactitol. Too much sorbitol trapped in retinal cells, the cells of the lens, and the Schwann cells that myelinate peripheral nerves, is a frequent result of long-term hyperglycemia that accompanies poorly controlled diabetes. This can damage these cells, leading to retinopathy, cataracts and peripheral neuropathy, respectively.