COMPARISON OF EMULSIONS IN THE CARE OF DEMANDING AND ATOPIC SKINS 419 The basic ingredients of balm (B5) water phase were glycerol and water (Table II). The oil phase consisted of, among others, evening primrose oil, palm oil, caprylic/capric triglyc- eride, and mineral oil. The lotion contained two amino acids: arginine and glycine. The former is responsible for effective epidermis moisture. The latter stimulates synthesis of collagen (33). According to the authors (34), synthetic ethoxylated polyethylene glycol and ethoxylated stearic acid in atopic skin care preparations may adversely affect the skin’s structure, caus- ing dryness and irritation. The presence of a mixture of lauric acid esters and ethoxylated sorbitan found in the preparation may be responsible for skin interactions (35). This component is used as an emulsifi er and stabilizer (36). Taking into account the aforementioned, there are synthetic compounds in most of the presented preparations. Because of the requirements and needs of atopic skin, the intro- duction of these compounds differs in function and purpose. Generally, this kind of skin requires proper hydration, nourishment, and protection against excessive water loss (37). Creating a formulation composition with a minimum amount of components, which are nonirritating, preventive, and caregiving, while also offering long shelf life, that is, high physical and antimicrobial stability, is extremely diffi cult. The study proposes a model emulsion system based on natural skin-related ingredients, without fragrances or irritants. A comparison was performed of its properties with the commercial products for atopic skin available in the market. ANALYSIS OF THE AUTHORS’ OWN FORMULATION COMPOSITION In the study, an emulsion was prepared on the basis of chemically interesterifi ed mutton tallow with sesame oil. The choice of fats was dictated by compatibility of the ingredients with human skin and by the ability to minimize unfavorable skin effects on application of the preparation. The proposed fat blend contained 75% of solid fat (mutton tallow) and 25% of liquid fat (sesame oil). Mutton tallow was selected because of its conditioning, greasing, and moisturizing properties, whereas the use of sesame oil was intended to en- rich the fat blend with the following fatty acids, important to atopic skin: oleic, linoleic, palmitic, and stearic acids, as well as phospholipids and natural antioxidant—lignan sesame (38). Other advantageous components used in our own preparation were natural emulsifi ers—soy lecithin and aloe vera leaf pulp. According to the authors (39,40), aloe vera leaf pulp contains the following: monosaccharides and polysaccharides, 13 vitamins (including B2, B6, and C), NMF such as amino acids, EFAs (essential fatty acids), and mineral compounds of organic origin. The use of this ingredient was also associated with its anti-infl ammatory, soothing, healing properties, and NMF effect on the skin rebuild- ing and improvement of lipid barrier function (39). DROPLETS’ SIZE AND THEIR DISTRIBUTION Figure 1 shows the presence of only one fraction. The range of droplet sizes for this emulsion was 0.58–11 μm and 95% of the present droplets had a diameter below 7.7 μm. The aver- age droplet size was 4.63 μm. Because of the fact that the range of droplets in emulsions is of 0.1–100 μm (41), it can be considered that the obtained result indicates the presence of small droplets in the emulsion, which demonstrates proper homogenization and hence

JOURNAL OF COSMETIC SCIENCE 420 good dispersion stability. Time, temperature, and other storage conditions can affect changes in the system, thus maintaining the proper stability. TURBISCAN TEST Analyzing the results of the Turbiscan test, it was found that the samples A—stored in a refrigerator—and C—stored at room temperature—were characterized by the highest stability. On the other hand, signifi cant destabilization changes were observed for the sample B—stored in the heater. Backscattered light intensity values decreased in the bot- tom and the top of the measuring cell. This profi le suggests occurrence of the creaming process. Moreover, variance of BS light intensity in the middle of the sample was observed, which indicates variation in emulsion droplet size (Figure 2B). In the case of emulsions stored at room temperature and in the refrigerator, the changes of BS light intensity curves were slight. The curves overlapped in the middle of the measuring cell thus the emul- sions showed no change due to coagulation and resizing of the droplets (Figure 2A and C). SKIN HYDRATION ANALYSIS The longest hydration effect after application was observed for cream (C5) among the fi ve tested commercial creams for AD (C1–C5). The hydration level was signifi cantly differ- ent from that of the remaining products after 30 min from application as well as after 60 and 120 min. The highest value was obtained after 30 min—74.6%. The value decreased over the successive test points: 99.3% was noted after 60 min, and after 120 min— 84.1%. These results indicate a high protection and appropriate atopic skin care. The lowest increase in skin hydration was observed after the application of cream (C4), after 30 min—27.3%, after 60 min—30.9%, and after 120 min—26.2% (Table III). In case of the analyzed balms, balm (B5) proved the most benefi cial for the skin. The increase in skin hydration was 68.4%, 72.8%, and 64.2%, respectively. The effect of the remain- ing balms was weaker, although without signifi cant variations. Figure 1. Droplets’ size and their distribution in own formulation.