Nonlamellar liquid crystalline nanostructured particles: advances in materials and structure determination

Analogous to the dispersion of lamellar phase-forming lipids to form liposomes, dispersion of lipids that form alternative liquid crystalline structures, such as cubic and hexagonal phase, forms particles termed cubosomes and hexosomes, respectively. Although these particles possess alternative structural forms and hence behavior, when compared to liposomes, they have received significantly less attention in the literature. While most studies have utilized glyceride lipids to prepare nonlamellar dispersions, recent advances in identifying new materials from which to prepare these particles has broadened the interest in this field. This review focuses on the materials used to form nonlamellar dispersions and the methods used to characterize their structure. Increased awareness of their structural characteristics and hence potential benefits in applications, such as drug delivery, is hoped to stimulate further studies that will ultimately see their uptake in commercial products.