General Description
Synonyms: Capmul GMS-50; Cutina GMS; 2,3-dihydroxypropyl octadecanoate; Geleol; glycerine monostearate; glycerin monostearate; glycerol monostearate; glyceroli monostearas; glycerol stearate; glyceryl stearate; GMS; HallStar GMS; Imwitor 191; Imwitor 900; Kessco GMS; Lipo GMS; monoester with 1,2,3-propanetriol; monostearin; Myvaplex 600P; Myvatex; 1,2,3-propanetriol octadecanoate; Protachem GMS-450; Rita GMS; stearic acid, monoester with glycerol; stearic monoglyceride; Stepan GMS; Tegin; Tegin 503; Tegin 515; Tegin 4100; Tegin M; Unimate GMS.
Description: While the names glyceryl monostearate and mono- and diglycerides are used for a variety of esters of long-chain fatty acids, the esters fall into two distinct grades:
40–55 percent monoglycerides The PhEur 6.0 describes glyceryl monostearate 40–55 as a mixture of monoacylglycerols, mostly monostearoylglycerol, together with quantities of di- and triacylglycerols. It contains 40–55% of monoacylglycerols, 30–45% of diacylglycerols, and 5–15% of triacylglycerols. This PhEur grade corresponds to mono- and di-glycerides USP– NF, which has similar specifications (not less than 40% monoglycerides).
90 percent monoglycerides The USP32–NF27 describes glyceryl monostearate as consisting of not less than 90% of monoglycerides of saturated fatty acids, chiefly glyceryl monostearate (C21H42O4) and glyceryl monopalmitate (C19H38O4). The commercial products are mixtures of variable proportions of glyceryl monostearate and glyceryl monopalmitate. Glyceryl monostearate is a white to cream-colored, wax-like solid in the form of beads, flakes, or powder. It is waxy to the touch and has a slight fatty odor and taste.
Chemical Name: Octadecanoic acid, monoester with 1,2,3-propanetrio
Functions
Emollient; emulsifying agent; solubilizing agent; stabilizing agent; sustained-release agent; tablet and capsule lubricant.
Uses
The many varieties of glyceryl monostearate are used as nonionic emulsifiers, stabilizers, emollients, and plasticizers in a variety of food, pharmaceutical, and cosmetic applications.
It acts as an effective stabilizer, that is, as a mutual solvent for polar and nonpolar compounds that may form water-in-oil or oil-in-water emulsions.
These properties also make it useful as a dispersing agent for pigments in oils or solids in fats, or as a solvent for phospholipids, such as lecithin.
Glyceryl monostearate has also been used in a novel fluidized hot-melt granulation technique for the production of granules and tablets.
Glyceryl monostearate is a lubricant for tablet manufacturing and may be used to form sustained-release matrices for solid dosage G 290 Glyceryl Monostearate forms.
Sustained-release applications include the formulation of pellets for tablets or suppositories, and the preparation of a veterinary bolus.
Glyceryl monostearate has also been used as a matrix ingredient for a biodegradable, implantable, controlledrelease dosage form.
When using glyceryl monostearate in a formulation, the possibility of polymorph formation should be considered.
The aform is dispersible and foamy, useful as an emulsifying agent or preservative.
The denser, more stable, b-form is suitable for wax matrices.
This application has been used to mask the flavor of clarithromycin in a pediatric formulation
Incompatibilities
The self-emulsifying grades of glyceryl monostearate are incompatible with acidic substances.
Safety
Glyceryl monostearate is widely used in cosmetics, foods, and oral and topical pharmaceutical formulations, and is generally regarded as a nontoxic and nonirritant material.
Handling Precautions
Observe normal precautions appropriate to the circumstances and quantity of material handled
Related Substances
Glyceryl monooleate; glyceryl palmitostearate; self-emulsifying glyceryl monostearate