• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.3
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• pp.237-254
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• 2019

This study is focused on the effect of sodium stearate, which is a hydrophilic gelling agent affecting on the hardness of O/W solid sunscreen cosmetic. The sunscreen of the O/W (oil in water) type is stable, good in use, and relatively easier to stabilize than the sunscreen of the W/O (water in oil) type. Methods for increasing the stability by using emulsifiers, electrolytes, and wax or oil have been studied for solid sunscreen. This study was intended to develop a solid sunscreen stabilized by increasing the hardness using sodium stearate as an O/W type containing more than 40% moisture. Response surface methodology (RSM) was used to analyze the factors affecting the hardness of cosmetics, and sodium stearate, polyol and oil were used for each factor. The hardness and the reaction value was measured using a rheometer. As a result, sodium stearate showed a meaningful value (p < 0.05) among the three factors affecting hardness. In addition, the use of sodium stearate as a hydrophilic gelling agent increased the usability and stability of the solid sunscreen.

• Economic and Environmental Geology
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• v.48 no.3
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• pp.247-253
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• 2015

Natural halloysite is mostly found in the form of a tubular structure with a 15-125 nm internal lumen. This kaolin clay can be used for encapsulating a liquid ingredient of cosmetics and for immobilizing an inorganic solid-phase ingredient. In this paper, the encapsulation and immobilization procedures are introduced and two example applications are reviewed to demonstrate the usefulness of halloysite as a cosmetics substrate. It may help attract more interest in cosmetic applications of halloysite and thus spur more research on the utilization of natural clays.

• Journal of Environmental Health Sciences
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• v.39 no.6
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• pp.505-512
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• 2013

Objectives: Ultraviolet (UV) radiation may cause skin cancer, photo-ageing, erythema, and sunburn. Benzophenone (BP) is commonly used to protect skin from UV radiation. In Korea, sunscreen, sunblock, socalled 'blemish balm' (BB) and 'color correcting' (CC) creams, and foundation may contain from 0.5 to 5% benzophenone in order to protect skin from UV radiation. The purpose of this study is to understand the levels of benzophenone derivatives in urine among a group of university students and identify the contribution of cosmetics use. Methods: Forty volunteers (20 women and 20 men) were asked about skin type, frequency of use of cosmetics, and recognition of related health effects, etc. in a survey. Subjects were divided into several subgroups and were compared for concentration of benzophenone-1 (BP-1) and benzophenone-3 (BP-3). Their urine was pretreated with enzyme hydrolysis and solid phase extraction. Determinations of BP-1 and BP-3 in the urine were made with LC-MS/MS. Results: Among the study subjects, 82.5% used basic cosmetics at least once per day, and 77.5% used sunscreens at least once per day. The concentrations of BP-1 and BP-3 of the males were 4.36 ng/mL and 9.16 ng/mL, respectively. Those of the females were 3.98 ng/mL and 5.07 ng/mL, respectively. The use of cosmetics was positively related to urinary benzophenone levels. Conclusions: BP-1 and BP-3 were widely detected among the university students. Cosmetic use was identified as a potential source. Implications of such exposure deserve further investigation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.1
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• pp.47-55
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• 2010

UV-screening agents have some adverse effects that raise consumers' concern. The organic agents often cause irritation and may penetrate into human body while the inorganic agents raise aesthetic issues because they often turn opaque. Organic agents with high molecular weights and nano-sized inorganic agents have been developed respectively to minimize transdermal intrusion into human body and suppress turning opaque. Recently, we reported preparation of powdery UV-screening agents made of polysilsesquioxane, an organic-inorganic hybrid material. Powders would not penetrate into epidermis and organic-inorganic hybrid nature would suppress the opaqueness problem. In this study, we continued our research on this powdery polysilsesquioxane UV-screening agent, SESQUV, regarding its chemical composition, its synergic UV-screening effects when mixed with other organic agents, and its applicability in practical formulation. Results showed SESQUV was promising UV-screening agents useful in sunscreen formulation.