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.
