Preparation and characterization of nanoemulsion formulations containing soy extract for hyperpigmentation problem

Pigmenter disorders are common dermatological disorders. It is related to endogenous and exogenous factors. These disorders are difficult to treat, hence, the need for skin lightening agents including cosmeceuticals. Due to the potential side effects of current treatments, there is a rising trend towards the development of effective and safe formulations containing naturally derived extracts for hyperpigmentation. Soy (Glycine soja) has evidenced to be both powerful and safe. A number of skin care products containing soy are available to improve hyperpigmentation. It has been proven by scientific studies that soy has positive effects on hyperpigmentation. In this thesis study, it is aimed to develop a cosmetic nanoemulsion with natural content, which coluld be an alternative to other products on the markets, effective on hyperpigmentation containing soy extract. Various nanoemulsions containing soy extract were prepared by using ultrasonicaton method. Then accelerated stability tests such as centrifuge and thermal tests were applied. pH value, viscosity, droplet size and polydispersity index of the formulations remaining stable were measured and organoleptic assessment was conducted. Each formulation that passed centrifuge and thermal tests was kept in ambient condition, in a refrigerator and in a climate chamber at 45°C, for two months. Measurement of pH value, viscosity, droplet size, polydispersity index and zeta potential and organoleptic assessment were conducted at predetermined time points. In addition, TPA (texture profile analysis) measurements of the formulations were made on the first day. As a result of all the tests mentioned, it was concluded that the F6P2 coded formulation containing %5 soy extract and 1% HPC as the best formulation could be beneficial in treatment of hyperpigmentation. Key words: Hyperpigmentation, soy extract, skin lightening herbs, ultrasonication, nanoemulsion