Chapter 10 - Solid lipid nanoparticles and nanostructured lipid carriers as novel carriers for cosmetic ingredients

Abstract

The stratum corneum, that consists of flat and cornified cells, is a major barrier that impedes the penetration of active ingredients of cosmetics/cosmeceuticals through the skin. Various types of penetration promoters, in which a small amount of active substance is closed, have been developed and applied to promote the effective transport of biologically active substances into the skin. Depending on their structure and composition, these chemical carriers have a different ability to penetrate and transmit the active ingredient to the target place, where the active substance is released. The most popular carriers, that also allow controlled release of active substances, which prolongs the period of its operation, include, for example, liposomes, nanosomes, cubosomes, forms of liquid crystals, transfersomes, or microcapsules. However, scientists have currently focused mostly on nanoparticle systems that are mainly based on lipids. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have attracted most attention of pharmacy and cosmetology industries. SLN are spherical particles composed of solid lipids at room temperature (e.g., triglycerides: tristearate, tripalmitate, some of glycerol monostearate, saturated fatty acids such as stearic and palmitic, steroids (cholesterol or waxes), cetyl palmitate). Then, these compounds, with the addition of emulsifier, are dissolved in the aqueous phase. NLCs are perfect complements to SLNs. They are carriers made from a mixture of solid lipids with oils. Both systems of lipid carriers can be widely used in the most modern moisturizing and antiaging preparations, conditioners, or sunscreens.