| Summary: | 碩士 === 嘉南藥理科技大學 === 化妝品科技研究所 === 95 === For decades, people have been in photodamage, primary due to the severely broken ozone layer in the atmosphere. During the day, most people apply suncreams on their skin for protecting them from photodamage such as spots, freckle, wrinkle, pigmentation, photoaging, skin disease, and even skin cancer. The needs for counteracting against the UV-induced skin damage and increasing skin protection agains UV rays lead to the development of suncreams with high effectiveness- or high SPF. However, it is well known that the higher the SPF of
suncreams, the greater the stimulating on skin. So it is important to search for the ways to improve SPF without increasing the level of sunscreen actives. A great number of such sunscreams have been commercialized. Indeed their quality, safety and effectiveness are not guaranteed. Moreover, most of the reports on these suncreams have been published in patent, it is really hard to obtain these suncream''s information including the know-how about production technique and commercialized secret. Hence, this study is designed to investigate the development of elegant suncreams with high safe and effectiveness. For the study, four of approved sunscreens are selected as active
agents against UV rays. Different compositions including sunscreen alone
and combinations of sunscreens are incorporated and various emulsification processes are performed. But in the presence of sunscreen, suncreams easily exhibit a tendency to have instability. Thus, their changes in physicochemical properties such as droplet size, conductivity, rheological behavior need to be realized to optimize sunscreen formulations. On the other hand, the efficacy of these suncreams is determined instrumentally by in vitro SPF method. From the results, we found that the instability of sun products will significantly impact on the efficacy. This will result in different SPF value in every part of a sun product. Fortunately, sunscreen formulations with good storage stability for storage are obtained when compared to the commercialized suncreams. Moreover, the suncreams with combinations exhibited higher SPF than those with sunscreen alone. Based on these findings, a desired formulations has been obtained . With high SPF of 60 and reasonable stability , it is composed of Covacream 3g, Squlane 3g, C.C.T. 3g, Finsolv TN 3g, MOS 70 6g. Parsol MCX 5g, Parsol 1789 2g、Benzophen-3 1g, TiO2 4g, Germaben II 0.8g, Carbopol 940 0.3g、P.G. 5g,
and deioned water to 100g.
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