Niosomes from 80s to present: the state of the art

Efficient and safe drug delivery has always been a challenge in medicine. The use of nanotechnology, such as the development of nanocarriers for drug delivery, has received great attention owing to the potential that nanocarriers can theoretically act as "magic bullets" and selectively target affected organs and cells while sparing normal tissues. During the last decades the formulation of surfactant vesicles, as a tool to improve drug delivery, brought an ever increasing interest among the scientists working in the area of drug delivery systems. Niosomes are self assembled vesicular nanocarriers obtained by hydration of synthetic surfactants and appropriate amounts of cholesterol or other amphiphilic molecules. Just like liposomes, niosomes can be unilamellar or multilamellar, are suitable as carriers of both hydrophilic and lipophilic drugs and are able to deliver drugs to the target site. Furthermore, niosomal vesicles, that are usually non-toxic, require less production costs and are stable over a longer period of time in different conditions, so overcoming some drawbacks of liposomes. The niosome properties are specifically dictated by size, shape, and surface chemistry which are able to modify the drug's intrinsic pharmacokinetics and eventual drug targeting to the areas of pathology. This up-to-date review deals with composition, preparation, characterization/evaluation, advantages, disadvantages and application of niosomes.