Recent patents on nonlamellar liquid crystalline lipid phases in drug delivery.

Lipid aggregates, mainly liposomes, have been used as drug carriers for quite some time. Recently, nonlamellar liquid crystalline lipid systems, such as inverted bicontinuous cubic, hexagonal and sponge mesophases, attract attention as possible drug-delivery vehicles because of their unique microstructure and physicochemical properties. Various bioactive molecules can be solubilized and protected from hydrolysis or oxidation in either the aqueous or the oil lipid phase. Nonlamellar liquid crystalline lipid aggregates have demonstrated high encapsulating capacity and ability for controlled release of drugs. Valuable properties such as a wide solubilization spectrum, high drug payloads, effective encapsulation, stabilization and protection of sensitive drug substances, define the nonlamellar lipid aggregates as promising pharmaceutical carriers. This review summarizes the recent patents on new formulations based on nonlamellar liquid crystalline lipid phases and their efficiency as drug carriers.