An ideal drug delivery system should be biodegradable and biocompatible and should incorporate the active pharmaceutical ingredient without losing or altering its activity. To optimize the drug’s therapeutic time window, the system should provide an efficient and controlled release mechanism for a drug at a specific location in vivo. Lipidic mesophases, a special class of materials belonging to the lyotropic-liquid-crystal family, meet those criteria. They thus share characteristics of both crystals and liquid materials: Like crystals, their molecules have short-range positional order, and like liquids, they lack long-range positional order. Lipidic mesophases exhibit distinct structures based on their composition, and they constitute an attractive alternative drug delivery system, capable of incorporating molecules of different polarity and size and protecting them from chemical and physical degradation.
As figure 1 depicts, when lipid molecules are hydrated, they can self-assemble in different arrangements that correspond to the lamellar, hexagonal, cubic, and micellar...
