LIPOSOMES: AN ADVANCE TOOLS FOR NOVEL DRUG DELIVERY SYSTEM

Abstract

Use of liposome‐encapsulated enzymes for delivery into cells was first reported in 1971. About the same time, a
specific receptor on hepatocytes was demonstrated to mediate clearance of ß‐galactose–terminated glycoproteins from circulation.
A mannoside‐specific receptor was recognized on the cell surface of the RES of rats (including the liver sinusiod and
macrophages). Liposomes are microscopic vesicles composed of a bilayer of phospholipids or any similar amphipathic lipids
They can encapsulate and effectively deliver both hydrophilic and lipophilic insoluble drug, because lipids are amphiphatic (both
hydrophilic and hydrophobic) in aqueous media, their thermodynamic phase properties and self assembling characteristics evoke
entropically driven sequestration of their hydrophobic regions into spherical bilayers are referred as lamellar. It provides
controlled drug delivery. It should be biodegradable, biocompatible, and flexible, non ionic, can carry both water and lipid soluble
drugs. Liposomes have been used to deliver anticancer agents in order to reduce the toxic effects of the drugs when given alone or
to increase the circulation time and effectiveness of the drugs.