Melt Emulsions: Influence of the Cooling Procedure on Crystallization and Recrystallization of Emulsion Droplets and their Influence on Dispersion Viscosity upon Storage

Solid lipid nanoparticles (SLN) are distinguishable from nanostructured lipid carriers (NLC) by the composition of the solid particle matrix. Both are an alternative carrier system to liposomes and emulsions. This review paper focuses on lipid nanoparticles for dermal application. Production of lipid nanoparticles and final products containing lipid nanoparticles is feasible by well-established production methods. SLN and NLC exhibit many features for dermal application of cosmetics and pharmaceutics, i.e. controlled release of actives, drug targeting, occlusion and associated with it penetration enhancement and increase of skin hydration. Due to the production of lipid nanoparticles from physiological and/or biodegradable lipids, this carrier system exhibits an excellent tolerability. The lipid nanoparticles are a "nanosafe" carrier. Furthermore, an overview of the cosmetic products currently on the market is given and the improvement of the benefit/risk ratio of the topical therapy is shown.

Poor aqueous solubility represents a major hurdle in achieving adequate oral bioavailability for a large percentage of drug compounds in drug development nowadays. Nanosizing refers to the reduction of the active pharmaceutical ingredient (API) particle size down to the sub-micron range, with the final particle size typically being 100-200 nm. The reduction of particle size leads to a significant increase in the dissolution rate of the API, which in turn can lead to substantial increases in bioavailability. This review describes the principles behind nanosizing, the production and characterization of nanoformulations as well as the current experience with utilization of such formulations in vivo.