INTRODUCTION Targeted delivery of a drug molecule to specific organ sites is one of the most challenging research areas in pharmaceutical sciences. By developing colloidal delivery systems such as liposomes, micelles and nanoparticles, new frontiers have opened for improving drug delivery. Nanotechnology and nanoscience are widely seen as having a great potential to bring benefits to many areas of research and applications. Nanomaterials differ significantly from other materials due to the following two major principal factors: the increased ABSTRACT Solid lipid nanoparticles are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery, clinical medicine and research as well as in other varied sciences.SLNs introduced in the beginning of the 1990s represent an alternative carrier system to traditional colloidal carrier systems. This review presents various production techniques for SLNs including their advantages and disadvantages, methods of characterizations, formulation variables, drug incorporation models and factors effecting loading capacity. Aspects of SLN route of administration and their applications in various fields are discussed.