| Summary: | 碩士 === 嘉南藥理大學 === 化粧品應用與管理系 === 102 === People need the sunlight for living but it will cause wrinkling, premature aging of the skin, hyperpigmentation macules and even skin cancer after overexposing. It is very important for us to protect their skin by avoiding overexposure to sunlight during the daytime. The use of Sunscreen products with broadspectrum UV-absorption is recommended in order to counteract against all kind of UV-induced skin damage. A great number of sunscreen products with different UV filters are available in the commercial market. However, some of them can cause degradation under extreme conditions such as UV radiation and evolved temperature, others may have storage instability. The occurrence of degradation or instability will result in the disadvantage changes in physical properties and the lower efficacy.
The purpose of this study was to evaluate the influence of single filter and different filter combinations on the storage stability and the sunburn protection of sunscreen products. In order to formulate sunscreen products, three chemical UV filters, Butyl methoxydibenzoylmethane（BMDBM, Parsol® 1789）、Octyl Methoxycinnamate(OMC, Parsol® MCX) and Diethylamino Hydroxybenzoyl Hexyl Benzoate(DHHB, Uvinul® A Plus) were selected. GMS( Glyceryl Monostearate) is the emulsifier and the emulsification is performed using different mixers（stirrer and homogenizer）. And then the obtained sunscreens were characterized by physicochemical properties including viscosity, rheological behavior during accelerated test. In addition, the amounts of UV filter were determined using HPLC-PDAD method to realize their degradation during accelerated test. Finally, products’ efficacy with time was tested by Labsphere UV-1000s transmittance analyzer (according to Food and Drug administration method).
In relating to physicochemical properties, the results showed that all the obtained sunscreens with single UV filters or different UV filter combinations have an esthetic appearance and good storage stability when homogenizer is used to disperse the oil and water phase. In addition, Sunscreen products including Uvinul A Plus have a better physicochemical properties and efficacy. Labsphere UV-1000S and HPLC-PDAD method show both the efficacy of products and the amounts of the UV filters were decreased with time.
Based on these findings, a desired sunscreen product was obtained. having high SPF but lower viscosity, good stability at 45℃testing for 90 days, good photostability, esthetic appearance, and good skin feel, it is composed of GMS1.6%、Mineral oil 12.00%、Parsol®MCX10.00%、Uvinul® A Plus5.00%、Carbopol®1342 0.104%、Amphisol K 0.64%、D.W 69.92%、Germaben Ⅱ0.64%、TEA 0.10%。
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