Solid Lipid Nanoparticles (SLNs): Advances in Modern Formulation Strategies for Drug Delivery – A Review

Abstract

Targeted delivery strategies are essentially designed for drugs with hydrophobic properties and deficient pharmacokinetic parameters. These systems provide a protective vehicle that stabilizes the drug during systemic circulation and facilitates its accumulation in target organs, effectively overcoming the inherent physiological limitations of the free drug. Bioavailability is influenced by several factors, including solubility and administration route. In the field of nanomedicine, solid lipid nanoparticles are distinguished from inorganic carriers by their excellent biocompatibility. Because they are composed of lipids that remain solid at body temperature, they provide a stable yet degradable vehicle that the body can break down safely, thereby minimizing the risk of systemic toxicity or organ accumulation. The design and performance of SLNs can be optimized through careful selection of lipid matrices, emulsifiers, active compounds or antioxidants, production methods, and specific therapeutic applications. SLN formulation typically requires the selection of appropriate lipid matrices and surfactants, with high-shear homogenization and ultrasonication representing the most commonly applied techniques because of their ease of implementation and consistent results. This review further highlights recent research and experimental data regarding different preparation methods and additives employed in the development of SLNs in recent years.