ABSTRACT
This chapter explains the preparation, characterisation and potential of Nanosized colloidal systems for cosmetic applications. Colloidal lipid aggregates such as liposomes were developed as vesicular carrier systems in cosmetics, too. Many cosmetic sunscreen formulations contain nanoparticles of titanium dioxide and zinc oxide as physical light filters. In comparison to microemulsions (ME), nanoemulsions are not thermodynamically stable. Nanocrystals are produced using two approaches: bottom-up and top-down technologies. The top-down technologies cover milling procedures such as pearl milling, high-pressure homogenization and combination technologies. MEs were developed for extremely lipophilic cosmetic actives which were in the past not able to penetrate into the skin or whose penetration into the skin had to be improved significantly by incorporation into MEs. MEs containing several peptides are in the late development stage. Furthermore, MEs with a hydrophilic model active were stabilized using carrageenan.
