Sorbitan monolaurate (Span 20)

• BPSorbitan Laurate
• Ph. Eur.Sorbitan Laurate
• USP–NFSorbitan Monolaurate

Sorbitan laurate; sorbitani lauras; Span 20; Arlacel 20; Crill 1; E493

Sorbitan monododecanoate (partial esters of sorbitol and its mono- and dianhydrides with lauric acid) · [1338-39-2]

UNII 6W9PS8B71J · PubChem CID 11046239

C18H34O6 · 346.5

Surfactant, emulsifier

Typical concentrations: — · Dosage forms: Semi-solid

A lipophilic nonionic surfactant used as an emulsifier, solubiliser and wetting agent in creams, emulsions and ointments for topical use, and in oral and other preparations. Of the sorbitan esters it is the most hydrophilic and is often combined with polysorbates to obtain the required HLB. Typical concentrations: emulsifier used alone in water-in-oil emulsions 1–15%; in combination with hydrophilic emulsifiers in oil-in-water emulsions 1–10%; to increase the water-holding capacity of ointments 1–10%; solubiliser for poorly soluble actives in lipophilic bases 1–10%; wetting agent for insoluble actives in lipophilic bases 0.1–3%.

A yellow to amber, viscous oily liquid with a faint characteristic odour and a bland taste. It is a mixture of esters of lauric acid with sorbitol anhydrides, the main component being sorbitan monolaurate.

HLB

8.6

Physical form

viscous liquid at room temperature

Solubility

insoluble but dispersible in water; soluble or dispersible in mineral and vegetable oils and in ethanol

Density

about 1.0 g/cm³

Gradual soap formation occurs with strong acids or bases; the esters are stable in weak acids and bases. Store in a well-closed container in a cool, dry place.

Incompatible with strong oxidising agents. Like other nonionic surfactants, it may reduce the activity of some preservatives such as parabens.

Prepared by dehydration of sorbitol to sorbitan (a mixture of cyclic anhydrides) followed by esterification with lauric acid, or by a one-step reaction of sorbitol and lauric acid at high temperature with a catalyst.

Sorbitan esters are widely used in cosmetics, foods and oral and topical pharmaceuticals and are generally regarded as non-toxic and non-irritant, although hypersensitivity skin reactions have occasionally been reported after topical use.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended.

Accepted as a food additive in Europe (E493). Included in the FDA Inactive Ingredient Database (oral and topical preparations) and in non-parenteral medicines licensed in Europe.

Polysorbate 20; sorbitan monooleate (Span 80); sorbitan monostearate (Span 60); sorbitan trioleate.

Blending a sorbitan ester with its corresponding polysorbate allows the HLB to be matched to the oil phase; for example, mixtures of Span 20 and polysorbate 20 cover an HLB range of about 8.6–16.7. Commercial products vary in fatty-acid and ester distribution, so specify the grade.