| Summary: | 碩士 === 嘉南藥理科技大學 === 化妝品科技研究所 === 95 === In the past 20 years, the ozone of stratospheric’s content decrease progressively 1% each year, and the rate of decrease is increasing continuously.
The research shows that a 2% increase in ultraviolet due to a 1%
decrease ozone, carry the different skin diseases.
The hygiene and academic organization of countries appealed repeatedly to use sunscreens for reducing risk by the ultraviolet exposure, that the high effective sunscreens are rising day by day on the market. However, in order to get the high effectiveness of sunscreen, the manufacturer often adds too much
dosage, that is easy to cause skin allergic problems.
The study target is to seek for the better effectiveness of sunscreen which is based on lower sunscreens. The study method is to screen the form of emulsions,
the oil, and to study different sunscreens’ interaction by reducing the amount of feckless sunscreen to reach better effectiveness of sunscreens .
The formula includes 33 kinds of W/O sunscreens and 4 kinds of O/W sunscreens in the study, and the result shows that W/O emulsifier type has better effectiveness of sunscreens. For selecting the oil, the similar chemical structures with sunscreens which can improve the compatibility and dispersedness of
sunscreens. On the other hand, the inorganic powder select coating with the oil surface modified by silica or hydrogenated polyisobutene, hydrogenated castor oilmonohydroxystearate and polyoxypropylene cetyl ether phosphate. For example: Eusolex T-AVO®and COVASCREEN TI, they can reduce powder agglutinately with formula’s base to decrease effectiveness of
sunscreens, and obtain more efficiency by use TiO2 than ZnO .
The study also shows that Octinaxate increases as the SPF value risen linearly (its linear coefficient correlation r =0.9797 and r =0.9850 respectively). The result offers the estimation of SPF value when the product produces. The
research also study the stable of sunscreens by exposing ultraviolet of 67.2W/m² for 24 hours, and the result shows that the effectiveness of sunscreen is not
decrease.
The main contribution of the research is not only using lower
sunscreens to get higher SPF value, but also redusing costs and irritation on
human skin.
|
|---|
