Solid lipid nanoparticles (SLNs) introduced at the beginning of the 1990s represents an alternative carrier system to traditional colloidal carriers, such as emulsions, liposomes and polymeric micro and nanoparticles. A number of admi nistration routes such as topical, oral, parenteral, nasal and pulmonary have been proposed for the delivery of SLNs. This paper reviews various production techniques for SLNs incl uding their advantages and disadvantages, drug incorporation, loading capacity with the facto rs affecting drug incorporation and loading capacity and drug release, especially emphasizing o n mechanism drug release.