J. Cosmet. Sci., 69, 411–428 (November/December 2018) 411 A Comparison of Physicochemical Properties of an Emulsion Containing Chemically Interesterifi ed Fat for Demanding Skin with Commercial Formulations for Atopic Skin MALGORZATA KOWALSKA, MAGDALENA WOŹNIAK, SLAWOMIR JANAS, and DIANA MRÓZ, Faculty of Material Science, Technology and Design, Kazimierz Pulaski University of Technology and Humanities, Radom 26-600, Poland (M.K., M.W., D.M.), Faculty of Economics and Legal Sciences, Kazimierz Pulaski University of Technology and Humanities, Radom 26-600, Poland (M.W., S.J.) Accepted for publication October 19, 2018. Synopsis The aim of the work was to evaluate and analyze the functional properties of a new emulsion product made according to our recipe containing interesterifi ed fat with the properties of selected popular preparations used in the care of atopic skin. Also, the composition of all tested preparations was analyzed for active substances contained in these preparations. Skin hydration level and transepidermal water loss (TEWL) after application of commercial formulations as well as of our own preparation on the basis of interesterifi ed fat were assessed. Determination of droplets’ size and their distribution was performed for our own preparation using dynamic laser diffraction technique. Stability of the prepared emulsion in different storage conditions was evaluated by the Turbiscan test. The highest average skin hydration increase was observed after the application of cream C5, which contained a unique component—evening primrose oil. The highest decrease in TEWL was obtained after the application of our own formulation. Sensory analysis showed that the highest scores were obtained for creams. Respondents evaluated our own preparation as not fully satisfying. The obtained results showed the possibility of producing an emulsion with interesterifi ed fat application as a formulation for atopic skin care. Its physical characteristics showed stability of the dispersion. However, parameters such as color, smoothing, cushion effect, and absorption should be improved. INTRODUCTION Atopic dermatitis (AD) is one of the skin diseases characterized by chronic infl ammation (1,2). Recently, increasing incidence of this disorder has been observed (3). On the basis of a World Health Organization survey, it can be concluded that this genetically contributed disease has a great impact on the quality of patients’ lives (4,5) by causing mental and Address all correspondence to Malgorzata Kowalska at email@example.com.
JOURNAL OF COSMETIC SCIENCE 412 physical discomfort. The symptoms of AD are dry skin, pruritus, and numerous defects in the skin structure—which can often be accompanied by asthma and allergic rhinitis (4). A whole range of these factors reduces the natural immune response of the skin, which causes problems with its regeneration. The clinical symptoms of AD consist in a disorder in the normal functioning of the skin barrier manifested by dry skin and excessive transepidermal water loss (TEWL). It occurs because of the damage of the epidermis and abnormalities in its structure. Reconstruction of the skin barrier is said to be the most important factor in preventing recurrence and progression of infl ammatory processes (6,7). A factor that has a signifi cant effect on epidermal barrier defect is the genetic disorder of structural proteins and stearic proteases and their inhibitors. It has been found that by the mutation of the fi laggrin gene, the defi ciency of these proteins in the skin is observed. Their defi ciency causes abnormalities in the shape of corneocytes, while simultaneously affect- ing the degeneration of lipid grouping. The consequence of these mutations is not only the natural moisturizing factor (NMF) defi ciency and reduced hydration of the stratum corneum but also increased TEWL. Moreover, the mutation results in an increased skin pH because of the heightened stearic protease activity and impairment of enzymes affect- ing lipid metabolism (6,8). Another determinant of the epidermal defect is a total lipids reduction in the epidermis, both in altered and unchanged skin. One of the abnormalities of lipid barrier composi- tion is the reduction in polyunsaturated fatty acids in the epidermis and increase in monounsaturated fatty acids. Oleic acid adversely affects the proper functioning of the epidermis. In the atopic skin, there are also higher cholesterol levels with regard to the concentration of this component in the unaltered skin (9). Defects in individual components of the lipid barrier include a reduced amount of ceramides (mainly one and three) in the epidermis, resulting in the incorrect production of laminar lamellas. In effect, excessive skin dryness and increase in TEWL are observed. Defi ciency of these compounds minimizes the con- tent of sphingosine, the key metabolite of ceramides (9). Both moisturizing substances and emollients are used to improve the atopic skin’s comfort. These compounds help to alleviate symptoms, restore normal epidermal barrier function, and replenish ceramide defects and valuable unsaturated fatty acids in the skin. The aim of the study was to propose a new emulsion product composition containing inter- esterifi ed fat for atopic skin care. The assumption was to obtain a model system based on interesterifi ed fat containing a minimum amount of the remaining components respon- sible for the system stability. Properties of own formulation and common commercial prod- ucts for atopic skin care were compared. MATERIAL During chemical interesterifi cation, the following chemicals were used: sodium methoxide (Merck, Darmstadt, Germany), diethyl ether (Chempur, Piekary Śląskie, Poland), phosphoric acid (Chempur), and magnesium sulfate (Chempur). The emulsion (own formulation) was prepared using the following components: distilled water, sesame oil (Oleofarm, Wroclaw, Poland), Mutton Tallow (Meat-Farm,
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