Shampoos are cosmetic hair products in which various surfactants are incorporated in order to remove dirt from the hair and scalp. They also affect foam stability and formulation viscosity. In addition to surfactants, proteins and peptides are also incorporated into hair cosmetic products. Whey, which is rich in protein, is becoming increasingly important and shows the ability to bind water and thus maintains the proper integrity of the skin. Cocamide diethanolamine is a widely used surfactant on the market. Compounds with cocamide diethanolamine are potentially carcinogenic, therefore manufacturers want to replace it with other, safer surfactants. Mixtures of several surfactants are known, such as STEPAN-MILD LSB, LATHANOL LAL POWDER, ALPHA-STEP PC-48, AMPHOSOL HCG and STEPAN-MILD GCC. In this thesis, we prepared 8 formulations of shampoos with the mentioned surfactants. We selected the 5 most optimal in terms of organoleptic characteristics and viscosity. We evaluated the influence of formulations with and without incorporated whey on transepidermal water loss. It is typical for surfactants to be irritating to the skin in excessively high concentrations and because of that we also tested solutions of surfactants in such concentrations as were included in the formulations. We also tested the influence of whey itself. Transepidermal water loss was measured using the Tewameter TM 300 device on a pig skin model in vitro, which was embedded in a Franz cell. We concluded that whey-based shampoo C was the most irritating to the skin, potentially because it contains 30% LSB, which we have measured to be the most irritating surfactant and therefore should be included in cosmetic products at a lower concentration. All the other shampoos showed a non-irritating effect on the skin, but whey-based shampoo A takes the lead, with the most moisturizing effect on the skin. Out of all the surfactant solutions tested, the 1 percent GCC solution showed the most beneficial effect on the skin barrier, whereas it has reduced transepidermal water loss the most. Whey itself has also improved the skin barrier, and by incorporating it, we have contributed to a better effect of the formulations on the skin. The results of testing solutions of surfactants and shampoos containing them allow to conclude that they represent an alternative to a potentially carcinogenic surfactant, cocamide diethanolamine.
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