The document discusses niosomes, which are vesicles composed of nonionic surfactants and cholesterol. Niosomes can encapsulate drugs and deliver them to target sites in the body, providing advantages over other drug delivery systems. The document outlines the general characteristics, advantages, disadvantages, structure, preparation methods, and applications of niosomes. It also compares niosomes to liposomes and discusses factors that affect the physicochemical properties of niosomes.