Liposomes are simply vesicles or ‘bags’ in which an aqueous volume is entirely enclosed by a membrane composed of lipid (fat) molecules, usually phospholipids.

                                                                                 
These spontaneously form when lipids are dispersed in water.

How are Liposomes Used?

Liposomes can be used to entrap materials such as drugs both within the central aqueous compartment if they are water soluble, or within the membrane if they are oil soluble.

Current Applications of Liposomes

Current applications of liposomes include:

• As vehicles to deliver drugs to specific parts of the body e.g. Ambiosome®, an antifungal drug (liposomal amphotericin B)
• To allow much smaller doses of drug to be used to reduce side effects
• Currently being studied for use in drug delivery therapies
• To effectively target various bacteria and enhance the inhibition of bacterial growth compared to equal concentrations of the free drug e.g. in toothpaste

What Determines the Behaviour of Liposomes in the Human Body?

The behaviour of liposomes in vivo is determined by:

• Physical size
• Chemical composition
• Membrane permeability
• Quantity of entrapped solutes

Source: “Biotechnology: The Characterisation and Use of Liposomes”