Cholesterol

• BPCholesterol
• JPCholesterol
• Ph. Eur.Cholesterol
• USP–NFCholesterol

cholesterin; cholesterolum; cholest-5-en-3β-ol

Cholest-5-en-3β-ol · [57-88-5]

UNII 97C5T2UQ7J · PubChem CID 5997

C27H46O · 386.65

Surfactant, emulsifier, Semi-solid base, emollient

Typical concentrations: — · Dosage forms: Semi-solid, Sterile (parenteral/ophthalmic)

Used as an emulsifying agent and emollient in topical creams and ointments, typically at about 0.3–5.0%, where it gives water-in-oil emulsions and increases the water-absorbing capacity of ointment bases. It is an essential membrane component of liposomes (commonly about 30–50 mol% of total lipid), where it reduces bilayer permeability and improves stability, and of lipid nanoparticles for nucleic acid delivery, which typically contain about 40 mol%.

White or faintly yellow, almost odourless pearly leaflets, needles, powder or granules. On prolonged exposure to light and air it gradually becomes yellow to tan.

Melting point

147–150 °C

Specific rotation

−34° to −38° (in dioxane)

Solubility

practically insoluble in water; sparingly soluble in acetone and ethanol; soluble in chloroform, ether and vegetable oils

Water absorption

greatly increases the water-absorbing capacity of hydrocarbon ointment bases

Stable, but slowly oxidised by light and air, forming oxysterols. Store in a well-closed container protected from light; material for parenteral use is often stored under inert gas at low temperature.

Precipitated by digitonin. Incompatible with strong oxidising agents.

Traditionally extracted from wool fat (lanolin) or from the spinal cord and brain of cattle, and purified by repeated crystallisation. Plant-derived and synthetic cholesterol, free of animal-derived material, is now available for parenteral and lipid nanoparticle products.

Cholesterol is present in all animal cells and is regarded as non-toxic and non-irritant at the levels used as an excipient. Material of bovine origin must comply with requirements to minimise the risk of transmitting spongiform encephalopathies.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended, and dust generation should be avoided.

Included in the FDA Inactive Ingredient Database (injectable liposomal products and topical and vaginal preparations, among others) and in parenteral and non-parenteral medicines licensed in Europe, including lipid nanoparticle vaccines.

Lanolin; lanolin alcohols; phytosterols; cholesterol for parenteral use.

The Ph. Eur. includes a separate monograph for cholesterol for parenteral use with tighter limits on related sterols and impurities. In liposomes and lipid nanoparticles, the source and purity of cholesterol (including oxidation products) should be controlled because they affect particle stability and performance.