Glyceryl monostearate

• BPGlyceryl Monostearate 40–55
• JPGlyceryl Monostearate
• Ph. Eur.Glycerol Monostearate 40–55
• USP–NFGlyceryl Monostearate

Capmul GMS-50; Cutina GMS; Geleol; glycerine monostearate; glyceryl stearate; GMS; Imwitor 491; Kessco GMS; monostearin; Tegin; E471

Octadecanoic acid, monoester with propane-1,2,3-triol (mixture with di- and triglycerides of stearic and palmitic acids) · [31566-31-1]

UNII 258491E1RZ · PubChem CID 24699

C21H42O4 · 358.56

Surfactant, emulsifier, Semi-solid base, emollient

Typical concentrations: — · Dosage forms: Semi-solid, Solid

A non-ionic emulsifier, stabiliser, emollient and consistency agent used in creams, lotions and ointments; self-emulsifying grades, which contain a small amount of soap or another anionic or non-ionic emulsifier, are used for oil-in-water creams. In oral solid dosage forms it serves as a lubricant, a hydrophobic matrix former for sustained release, a binder in melt granulation and a coating or taste-masking agent; it is also used in solid lipid nanoparticles. It is widely used in foods and cosmetics.

A white to cream-coloured, waxy solid supplied as beads, flakes or powder, waxy to the touch and with a slight fatty odour and taste. Ph. Eur. glycerol monostearate 40–55 contains 40–55% monoacylglycerols, mainly of stearic and palmitic acids; higher-monoester (distilled) grades are also available.

Melting range

about 55–60 °C (40–55 grade)

HLB

≈ 3.8 (non-self-emulsifying grades)

Polymorphism

occurs in α and β forms; the α form produced on rapid cooling slowly converts to the stable β form

Solubility

soluble in hot ethanol, chloroform, hot acetone, ether, mineral oil and fixed oils; practically insoluble in water but can be dispersed in hot water with a surfactant

If stored at warm temperatures its acid value rises because of ester hydrolysis, and polymorphic change can alter the consistency of creams and the release from matrices over time. Store in a tightly closed container in a cool, dry place, protected from light.

Self-emulsifying grades are incompatible with acidic substances, which neutralise the soap emulsifier.

Prepared by glycerolysis of hydrogenated fats or oils, or by direct esterification of glycerol with stearic acid; molecular distillation is used to obtain grades rich in monoglycerides.

Widely used in foods, cosmetics and oral and topical medicines, and regarded as non-toxic and non-irritant.

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

Mono- and diglycerides are GRAS listed and accepted as food additives in Europe (E471). Glyceryl monostearate is included in the FDA Inactive Ingredient Database (oral capsules and tablets; topical and vaginal preparations) and in non-parenteral medicines licensed in Europe.

Glyceryl behenate; glyceryl monooleate; glyceryl palmitostearate; self-emulsifying glyceryl monostearate; mono- and diglycerides.

The term covers materials with quite different monoglyceride contents, so the pharmacopoeial grade and supplier should be specified. Because the α-to-β transition is slow, products made with molten glyceryl monostearate should be checked on storage for changes in hardness, viscosity or drug release.