ABSTRACT
Aqueous dispersions of smectic cholesterol ester nanoparticles can be prepared by high-pressure homogenization of a hot pre-emulsion at temperatures above the melting point of the respective matrix lipid in the presence of emulsifiers. High-pressure melt-homogenization yields dispersions of smectic nanoparticles with mean particle sizes between 100 and 200 nm, avoiding the use of organic solvents. The common feature of stabilizers resulting in smectic nanoparticles with a multiple crystallization pattern, and a comparatively high recrystallization tendency upon storage is the presence of an acyl chain in the molecule. Ibuprofen, miconazole, etomidate, and progesterone were used as poorly water-soluble model drugs for the preparation of drug-loaded smectic nanoparticles. Supercooled smectic cholesterol ester nanoparticles are a promising new carrier system for the delivery of lipophilic drugs. The lipidic nature and small particle size of supercooled smectic nanoparticles offer several interesting possibilities with virtually all ways of administration.
