Novel Drug Delivery System (NDDS): Niosomes.

Abstract

Different carriers like liposomes, niosomes, microspheres, resealed erythrocytes, dendrimers, aquasomes, trasfersomes, ethosomes, phytosomes, nanoparticles etc. are used in novel drug delivery system. Vesicular systems are a novel means of drug delivery that can enhance bioavailability of encapsulated drug and provide therapeutic activity in a controlled manner for a prolonged period of time. Liposomes were the first such system but they suffer from a number of drawbacks including high cost and lack of stability at various pHs. Niosomes are non-ionic surfactant vesicles obtained on hydration of synthetic nonionic surfactants, with or without incorporation of cholesterol or other lipids. Niosomes are one of the best carriers for drug targeting. The basic method of preparation is the same as liposomes i.e. hydration of the lipid phase by aqueous phase which may be either a pure surfactant or a mixture of surfactant with cholesterol. Niosomes are promising vehicle for drug delivery and being non-ionic; it is less toxic and improves the therapeutic index of drug by restricting its action to target cells. Niosomal drug delivery is potentially applicable to many pharmacological agents for their action against various diseases. This review article deals with advantages, preparation, separation of unentrapped drug, factors affecting vesicles size, entrapment efficiency and release characteristics of niosomes, evaluation, applications and Marketed formulations of niosomes.
KEYWORDS: Niosomes, NDDS, Surfactant, Ether injection, Entrapment, Dialysis.