Solid lipid nanoparticles for drug delivery

Solid lipid nanoparticles (SLN) are an improvement to well known nanoemulsions and liposomes. Compared to these systems, they offer the possibility of a sustained release due to their solid matrix. In this review, the physicochemical properties and the consequences on pharmacokinetics are discussed. The pharmacokinetics of drugs incorporated in SLN differ from those of drugs administered as solution or drug suspension. In many cases, bioavailability can be increased, especially for drugs with poor solubility. Furthermore, particulate systems can alter the biodistribution of drugs and offer the possibility of drug targeting to tumors, the brain and the liver, since the surface of SLN can easily be modified. These biopharmaceutical features are reviewed as well.