Introduction : Liposomes were discovered in the early 1960 by Bangham and colleagues (Bangham et al., 1965 ) and subsequently became the most extensively explored drug delivery system. Liposomes are concentric bilayered vesicle in which an aqueous volume is entirely enclosed by a membranous lipid bilayer mainly composed of natural or synthetic phospholipids. A liposome can be formed at a variety of sizes as uni-lamellar or multi-lamellar construction, and its name relates to its structural building blocks, phospholipids, and not to its size. Liposomes are artificially prepared vesicles made of lipid bilayer. The name liposome is derived from two Greek words: 'Lipos' meaning fat and 'Soma' meaning body. A liposome does not necessarily have lipophobic contents, such as water, although it usually does. Liposomes can be filled with drugs, and used to deliver drugs for cancer and other diseases. Liposomes can be prepared by disrupting biological membranes, for example by sonication. Liposomes are micro particulate or colloidal carriers, usually 0.05- 5.0 μm in diameter which form spontaneously when certain lipid are hydrated in aqueous media. Liposomes are composed of relatively biocompatible and biodegradable material, and they consist of an aqueous …show more content…
The hydrophobic tail is composed of two fatty acid chains containing 10-24 carbon atoms and 0-6 double bonds in each chain. The polar end of the molecules is mainly phosphoric acid bound to a water-soluble molecule. The hydrophilic and hydrophobic domains/segments within the molecular geometry of amphiphilic lipids orient and self organize in ordered supramolecular structure when confronted with solvents. The macroscopic structures most often formed include lamellar, hexagonal or cubic phases dispersed as colloidal nanostructures referred to as liposomes, hexasomes or cubosomes,