Liposomes as drug carrier systems. Preparation, classification and therapeutic advantages of liposomes]

Bangham et al. (1965) created first the concept of the liposome as a microparticulate lipoidal vesicle separated from its aqueous environment by one or more lipid bilayers. Later Gregoriadis and Ryman (1972) suggested to use liposomes as drug carrier systems. Nowadays liposomes are under extensive investigation for improving the delivery of therapeutic agents, enzymes, vaccines and genetic materials. Liposomes offer an excellent opportunity to selective targeting of drugs which is expected to optimize the pharmacokinetical parameters, the pharmacological effect and to reduce the toxicity of the encapsulated drugs. To understand the system it is important to know the basic properties of these lipoidal vesicles. Our aim was to focus on the lipid composition and the method of liposome preparation what determine the liposomal membrane fluidity, permeability, vesicle size, charge density, steric hindrance and stability of the liposomes as principle factors those influence the fate of liposomes, their interactions with the blood components and other tissues after systemic administration or local use.