Hexosomes based on cholesterol and phosphatidylcholine: a new drug delivery system for curcumin release

Hexosomes are lyotropic liquid crystalline systems with the ability to achieve a sustained release of the encapsulated drug, possess bio-adhesive properties, can solubilise both hydrophilic and lipophilic drugs. The LLC are complex systems with a thermodynamically stable morphology and with a wide range of sizes [1]; with the properties of both liquids (fluidity) and solids (organized crystalline structure and optical anisotropy) [2]. In the present study hexosomes were prepared and optimized using natural lipids, phosphatidylcholine and cholesterol. TEM analysis and Small angle X-ray diffraction profiles confirmed the presence of the hexagonal phase. Curcumin, the main biologically active component from the rhizome of Curcuma longa (Zingiberaceae), is a polyphenolic compound insoluble in water, having a low bioavailability [3]. 1, 5 and 10% w/w of curcumin was added to the hexosome formulation. TEM analysis showed that only 1% curcumin w/w was compatible with the hexagonal systems, while at higher concentrations a collapse of the system was evident. Addition of curcumin didn't change the size of the two populations (350 ± 6.6nm and 100 ± 4.5nm). Drug-entrapment efficiency was 51 ± 0.12%. Release studies conducted at pH 1.2 demonstrated that the developed hexosomes are able to achieve a "sustained release” of curcumin. The developed new hexosomes suggest a potential application not only limited as drug carriers, but also for food, dietary supplements and cosmetic formulations.