ABSTRACT
Solid lipid nanoparticles (SLNs) are an effective alternative to the conventional lipid-based nanomedicines, for example, liposomes. SLNs and nanostructured lipid carriers are useful for encapsulation of lipophilic drugs but rarely hydrophilic drugs. Stability of the SLNs is an issue especially when they are used as drug delivery systems. The preferred ways for storage of SLNs are spray drying and lyophilization. Adequate sterilization is a prerequisite, especially for parenteral administration of SLNs. SLNs, unlike liposomes, are known to demonstrate very high encapsulation efficiency. Like liposomes, SLNs can also be prepared in stealth varieties by decorating the surface with hydrophilic molecules, most commonly polyethylene glycol. The usual side effects of SLNs mimic that of liposomes. Fortunately, SLNs have demonstrated high biocompatibility in vivo. SLNs can also be produced by high-speed stirring or by the simple use of ultrasonicator present often in many labs.
