Abstract

LIPOSOMES: A PROMISING VESICULAR CARRIER IN NOVEL DRUG DELIVERY SYSTEMS

Himanshu*, Usha Singh, Sameeksha and Yogesh Kumar

ABSTRACT

Lipid vesicles or more precisely liposome, is a term that is derived from two Greek words, ‘Lipos’ means fat and ‘Soma’ which means body. These spherical, self-contained structures have an inner core that is enclosed by one or more concentric lipid bilayers. Their size generally ranges from 20 nm to few microns and the thickness of lipid bilayer usually lies in nanoscale range. Since their inception in 1960s as conventional vesicles, they have witnessed tremendous technolgical development that has led to formation of ‘second generation liposomes which possess long circulating time in body. Liposomes exhibits superior properties like better solubility , enhanced bioavailability, lower dose size, biodegradable nature of lipid bilayer etc, over the conventional drug delivery systems. Different methods are being employed for liposomes preparation like ether injection, hydration method, sonication, microemulsification, reverse evaporation, freeze thawed technique etc. The method of preparation depends on various parameters like lipid bilayer composition, route of administration, disease in which liposomal formulation is required etc. Liposomes are generally characterized for shape, size, surface properties, lamellarity, phase behaviour and drug release profile etc. This article briefly summarises the classification, methods of preparation, characterization and application of liposomes.

Keywords: Nanoscale, Bioavailability, Biodegradable, Encapsulate, Self-enclosed.