Proniosomes are non-ionic surfactant based vesicles that can be hydrated to yield an aqueous niosomal dispersion. The evolution of proniosomes has been motivated by development of niosomes to minimise the stability problems of niosomes and liposomes. Moreover, proniosomes can encapsulate both hydrophilic and lipophilic drugs. They are effective in enhancing skin penetration for transdermal delivery. This article describes key compositions of a proniosomal system, types of proniosomes, preparation techniques, and their characteristic properties including particle size, morphology, flow ability, entrapment efficiency, drug release, and permeability performance. The advantages of proniosomes, the mechanism of action in skin penetration, and the toxicity of proniosomes are discussed. Several categories of drugs formulated for a proniosomal system and topical or transdermal delivery are also reviewed.
