Monoolein and Phytantriol Main Building Blocks of Lipids Mesophases

1 Monoolein and Phytantriol Main Building Blocks of Lipids Mesophases 

Only a few synthetic amphiphiles can mimic the behavior of biological lipids and form inverted mesophases. The unsaturated monoglycerides (monoolein and monolinolein) belong to this category [10, 64]. GMO is the preferred amphiphile for formulating LC phases for scientific research and drug delivery. This is a nontoxic, biocompatible, and biodegradable lipid, which possesses low water solubility, but swells and forms several LC phases in excess water. 

Another lipid, phytantriol, was also recently shown to form cubic LC. Phytantriol is commonly used as an ingredient in the cosmetics industry for improving moisture retention [11, 65]. Its phase behavior as a function of water concentration and temperature is very similar to that of GMO, although structurally they are very different [11, 66] (Fig. 12.2). 

The cubic and hexagonal phases based on GMO/water and GMO/oleic acid/ water, respectively, are well studied and were shown to have the ability to sustain the release of incorporated compounds [59, 67, 68]. Moreover, each component constructing either the cubic or the hexagonal phase is a penetration enhancer by itself. GMO is known to promote ceramide extraction and enhancement of lipid fluidity in the stratum corneum, and oleic acid is considered to increase epidermal permeability via a mechanism involving perturbation of the stratum corneum lipid bilayers and lacunae formation [69]. 

2 Hexagonal and Cubic Mesophases and Their Dispersions as Carriers of Hydrophilic Drugs Cubosomes, Hexosomes and Micellosomes 

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