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Copyright @ Pol J Cosmetol
Pol J Cosmetol 2022, 25(2): 97-102pl,en  Influence of carboxylic acids on the lipophilicity and skin permeation of zinc saltsJacek Arct 1/, Anna Frydrych 2/, Katarzyna Pytkowska 3/, Krzysztof Kasiura 4/ 1/ Fundacja dr Seidla w Warszawie 2/ Bielenda Kosmetyki Naturalne sp. z o.o. w Krakowie 3/ Uczelnia Medyczna im. Marii Skłodowskiej Curie w Warszawie 4/ Wyższa Szkoła Zawodowa Kosmetyki i Pielęgnacji Zdrowia w Warszawie Summary Introduction. Zinc compounds are popular ingredients in cosmetic preparations. They are introduced as additives improving the physical and chemical properties of the formula, as pigments and in decorative cosmetics. In addition, some zinc compounds are used as active ingredients that can influence the physiological processes in the skin. Aim. It is generally accepted that the counterion is a crucial factor in metal ion penetration through the stratum corneum. Due to the broad spectrum of action in the skin and low toxicity, zinc is one of the metals most commonly used in cosmetics. Therefore, all research on the cosmetic bioavailability of zinc is of great importance. Materials and methods. The research was carried out using the shake flask method and in Flynn and Franz diffusion cells, using model membranes imitating the lipid membrane of the stratum corneum. An acid solutions in a buffered aqueous zinc acetate solutions were used as donor systems. Typical analytical methods were used to perform the analyzes. Results. It was found that the transfer of zinc ions is related to the lipophilicity of the carboxylic acid expressed as the zinc partition coefficient in the octanol/water system. The maximum permeation coefficient was obtained in the presence of pentanoic and hexanoic acids. A further increase in the carboxylic acid chain length or its concentration resulted in a decrease in zinc ions´ transfer coefficients. Conclusions. The addition of carboxylic acids may affect the bioavailability of zinc ions, which should be taken into account when developing recipes. Key words: zinc, logP, lipophilicity, permeation, carboxylic acids |