Caprylocaproyl polyoxylglycerides

• BPCaprylocaproyl Macrogolglycerides
• Ph. Eur.Caprylocaproyl Macrogolglycerides
• USP–NFCaprylocaproyl Polyoxylglycerides

Labrasol; Labrasol ALF; Acconon MC8-2; caprylocaproyl macrogol-8 glycerides; macrogolglyceridorum caprylocaprates; PEG-8 caprylic/capric glycerides

Mixture of mono-, di- and triglycerides and of mono- and di-fatty acid esters of macrogols, the fatty acids being mainly caprylic (C8) and capric (C10) acids · [—]

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

Solubilising agent, Surfactant, emulsifier

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

Used as a solubiliser, surfactant and co-surfactant in lipid-based oral formulations, particularly self-emulsifying and self-microemulsifying drug delivery systems (SEDDS/SMEDDS) filled into capsules, to improve the solubility and absorption of poorly water-soluble drugs. It is also used as a penetration enhancer and solubiliser in topical preparations.

A pale-yellow, oily liquid with a faint odour. It is a mixture of medium-chain glycerides and polyethylene glycol (macrogol) esters, typically based on macrogol 400.

HLB

≈ 12 (macrogol 400 grade)

Fatty-acid composition

caprylic acid 50–80% and capric acid 20–50% (Ph. Eur.)

Physical form

pale-yellow oily liquid at room temperature

Solubility

dispersible in water, forming a fine (micro)emulsion; soluble in ethanol and methylene chloride; practically insoluble in mineral oil

Stable when stored in an airtight container protected from light and moisture. The macrogol component can form peroxides on prolonged exposure to air.

Incompatible with strong oxidising agents. Peroxide and aldehyde impurities from the macrogol chains may degrade oxidation-sensitive drugs, and the liquid can interact with gelatin capsule shells, so compatibility of fill and shell should be checked.

Prepared by partial alcoholysis of medium-chain triglycerides with macrogol, or by esterification of glycerol and macrogol with caprylic and capric acids.

Used in marketed oral and topical products and generally regarded as of low toxicity. High oral doses may cause gastrointestinal irritation or diarrhoea, and the material can be mildly irritant to skin and eyes.

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

Included in the FDA Inactive Ingredient Database (oral preparations) and in medicines licensed in Europe.

Lauroyl polyoxylglycerides; linoleoyl polyoxylglycerides; oleoyl polyoxylglycerides; stearoyl polyoxylglycerides; medium-chain triglycerides.

It is usually combined with an oil and a co-solvent such as diethylene glycol monoethyl ether in lipid formulations; the performance of such systems should be checked by dispersion and in-vitro lipolysis tests rather than by solubility alone.