Glyceryl palmitostearate

• BPGlycerol Distearate
• Ph. Eur.Glycerol Distearate
• USP–NFGlyceryl Distearate

Precirol ATO 5; glycerol palmitostearate; glyceryl distearate; glycerol distearate

Mixture of mono-, di- and triglycerides of palmitic (C16) and stearic (C18) acids, with diglycerides predominating · [8067-32-1]

Polymer, mixture or material of variable composition — no single molecular formula applies.

Lubricant

Typical concentrations: 1–3% lubricant · Dosage forms: Solid

Used in oral solid dosage forms as a tablet and capsule lubricant, as a lipophilic binder in melt granulation and as a hot-melt coating agent for taste masking or modified release. At higher levels it forms inert, non-swelling matrices for sustained release. It is also widely used to prepare solid lipid nanoparticles and nanostructured lipid carriers, and in topical products as a consistency agent.

A fine white powder or waxy solid with a faint odour. The fatty-acid fraction consists mainly of palmitic and stearic acids, and diacylglycerols form the largest part of the glyceride mixture.

Melting range

about 50–60 °C

HLB

≈ 2

Iodine value

low (saturated fatty acids)

Solubility

soluble in chloroform and dichloromethane; practically insoluble in water, ethanol and mineral oil

Chemically stable. After melting it may recrystallise in less stable polymorphic forms that change slowly on storage, which can alter drug release; a controlled curing (annealing) step is often used. Store in a tightly closed container in a cool place, protected from heat and light.

No major chemical incompatibilities have been reported. As a hydrophobic material, excessive amounts can slow disintegration and dissolution.

Made by esterifying glycerol with palmitic and stearic acids obtained from hydrogenated vegetable oils, followed by spray-cooling (atomisation) of the molten product to give a fine powder.

Used in oral and topical pharmaceutical products and in cosmetics, and regarded as essentially non-toxic and non-irritant.

Observe normal precautions for the quantity handled; eye protection and gloves are recommended, with a dust mask where dust is generated.

Included in the FDA Inactive Ingredient Database (oral capsules and tablets) and in non-parenteral medicines licensed in Europe.

Glyceryl behenate; glyceryl monostearate; hard fat; hydrogenated vegetable oil.

Its lower melting point compared with glyceryl behenate makes it convenient for melt processes at moderate temperatures. Release from lipid matrices and coatings depends on the solid-state form of the lipid, so stability studies should monitor dissolution after storage.