A review on Solid Lipid Nanoparticles (SLN) for controlled and targeted delivery of medicinal agents

Solid lipid nanoparticles (SLN) were introduced as alternative carrier system to traditional colloidal carriers, such as emulsions, liposomes and polymeric micro- and nanoparticles. SLN combine advantages of the traditional systems but avoid some of their major disadvantages. Nanoparticles are sub-nanosized colloidal structures composed of synthetic or semi synthetic polymer. The colloidal carriers based on biodegradable and biocompatible polymeric system have largely influenced the controlled and targeted drug delivery concept. Nanoparticle loaded bioactive could not only deliver drug to specific organ within the body but delivery rate in addition could be controlled as being bystanders, burst, controlled pulsatile or modulated. This paper reviews the present methods and techniques regarding production of SLN, drug incorporation, loading capacity and drug release, especially focusing on drug release mechanisms. Relevant issues for the introduction of SLN to the pharmaceutical market, such as status of excipient, toxicity/tolerability aspects and sterilization and long-term stability including industrial large scale production are also discussed. The potential of SLN to be exploited for the different administration routes is highlighted.