Functional Category
Bioadhesive material; emollient; emulsifying agent; emulsion stabilizer; gelling agent; mucoadhesive; nonionic surfactant; sustained-release agent.
Applications in Pharmaceutical Formulation
Glyceryl monooleate is a polar lipid that swells in water to give several phases with different rheological properties.(1) It is available in both nonemulsifying (n/e) and self-emulsifying (s/e) grades, the self-emulsifying grade containing about 5% of an anionic surfactant. The nonemulsifying grade is used in topical formulations as an emollient and as an emulsifying agent for water-in-oil emulsions. It is also a stabilizer for oil-in-water emulsions. The self-emulsifying grade is used as a primary emulsifier for oil-in-water systems.(2) Glyceryl monooleate gels in excess water, forming a highly ordered cubic phase that can be used to sustain the release of various water-soluble drugs.(3–6) It is also the basis of mucoadhesive drug delivery systems.(7,8) Glyceryl monooleate is reported to enhance transdermal(9) and buccal penetration.
Description
The PhEur 6.3 describes glyceryl monooleate as being a mixture of monoacylglycerols, mainly monooleoylglycerol, together with variable quantities of di- and triacylglycerols. They are defined by the nominal content of monoacylglycerols (see Table I) and obtained by partial glycerolysis of vegetable oils mainly containing triacylglycerols of oleic acid or by esterification of glycerol by oleic acid, this fatty acid being of vegetable or animal origin. A suitable antioxidant may be added. Glyceryl monooleates occur as amber oily liquids, which may be partially solidified at room temperature and have a characteristic odor.
Stability and Storage Conditions
Glyceryl monooleate should be stored in an airtight container, protected from light in a cool, dry place.
Incompatibilities
Glyceryl monooleate is incompatible with strong oxidizing agents. The self-emulsifying grade is incompatible with cationic surfactants.
Safety
Glyceryl monooleate is used in oral and topical pharmaceutical formulations and is generally regarded as a relatively nonirritant and nontoxic excipient.