Solid lipid nanoparticles (SLNs)

Solid lipid nanoparticles (SLNs) are generally spherical in shape and consist of a solid lipid core stabilized by the surfactant interfacial region. SLNs combine the advantages of lipid emulsion systems and polymeric nanoparticle systems. This new colloidal drug carrier system enables a variety of routes of administration such as oral, topical, parenteral, ophthalmic and rectal routes. Compared to other colloidal systems, SLNs have many advantages, such as the possibility of large-scale manufacture and enhanced absorption of various drugs (hydrophilic or lipophilic), where in the absorption of nanoparticles (NPs) occurs through several mechanisms, For example, nanoparticles can be absorbed by the Peyer’s patches either in the intracellular or paracellular pathway. Moreover, drug delivery via SLNs largely avoids hepatic first-pass effects due to absorption into the lymphatic circulation, which bypasses the liver.

Due to the solid nature of the lipid matrix, SLNs can be lyophilized and transformed into the conventional oral solid dosage forms such as tablets and capsules. SLNs can be prepared by several methods: high-pressure homogenization (hot and cold homogenization), solvent evaporation, solvent emulsification–diffusion, microemulsion, double emulsion, and high-shear homogenization followed by ultrasonication. In the homogenization/ultrasonication method, the main parameters affecting the particle size of the SLN formulation are the type of lipid, the type of emulsifier, the concentrations of lipid, and the homogenization and sonication time.

Learn more: Solid Lipid Tablets