Description
Glyceryl monooleate (GMO), generally referred to as monoolein (MO), is FDA approved amphiphilic lipid that is widely used during the synthesis of cubosomes. Glyceryl monooleate is a waxy material, but its physical form is dependent on the content of di- and triglyceride. GMO is a polar unsaturated monoglyceride that can self-assemble in water into bicontinuous cubic structures. The amphiphilic chemical structure of GMO with hydrophilic polar head (hydroxyl groups) and hydrophobic chains in the tail facilitates H-bond formation with water. GMOs are classified as GRAS (generally recognized as safe) due to their biodegradability, biocompatibility, and minimal toxicity. The biodegradability was attributed to the lipolysis of GMOs in different tissues via esterase activity. The GMO-based systems, especially bicontinuous cubic and hexagonal LC phases, were highly reported as promising drug delivery. Thanks to their unique features, which include their minimal toxicity, prolonged release rate, and thermodynamic stability upon exposure to excess water.
Chemical Properties
Glyceryl monooleate is a polar lipid with a faint fatty odor. It is a mixture of glycerides, primarily consisting of monooleate, derived from oleic acid and other fatty acids. This compound is characterized by its ability to swell in water, forming several phases with varying rheological properties. It is composed mainly of monoacylglycerols, with monooleoylglycerol being the predominant form, along with varying amounts of di- and triacylglycerols. The composition is defined by the nominal content of monoacylglycerols and is typically obtained through partial glycerolysis of vegetable oils rich in triacylglycerols of oleic acid or by the esterification of glycerol with oleic acid, which can be sourced from either vegetable or animal origins. Glyceryl monooleates are often amber oily liquids that may be partially solid at room temperature and are known for their characteristic odor. An appropriate antioxidant may be added to the formulation.
Uses
Glycerol Monoleate is used to synthesize water soluble drugs in need of sustained-release for drug delivery.
Uses
93% 1-Oleoyl, 7% 2-oleoyl
Definition
An antifog agent and dispersant.
Production Methods
Glyceryl monooleate is prepared by the esterification of glycerol
with fatty acids, chiefly oleic acid. As the fatty acids are not pure
substances, but rather a mixture of fatty acids, the product obtained
from the esterification will contain a mixture of esters, including
stearic and palmitic. Di- and triesters may also be present. The
composition and, therefore, the physical properties of glyceryl
monooleate may thus vary considerably from manufacturer to
manufacturer; e.g. the melting point may vary from 10–35°C.
Pharmaceutical Applications
Glyceryl monooleate is a polar lipid that swells in water to give
several phases with different rheological properties. 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.
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.It is also the basis of mucoadhesive
drug delivery systems.
Glyceryl monooleate is reported to enhance transdermal and
buccal penetration.
Safety Profile
When heated to
decomposition it emits acrid smoke and irritating fumes.
Safety
Glyceryl monooleate is used in oral and topical pharmaceutical
formulations and is generally regarded as a relatively nonirritant
and nontoxic excipient.
storage
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.
Regulatory Status
GRAS listed. Included in the FDA Inactive Ingredients Database
(oral capsules, oral powder, oral tablets; creams, controlled-release
transdermal films). Included in nonparenteral medicines licensed in
the UK. Included in the Canadian List of Acceptable Non-medicinal
Ingredients.
