本研究利用皮膚彈力(Elasticity)測定儀(Cutometer)以及UVA光照皮膚地形圖(Skin Topography)顯微攝影機(Visioscan),評估自製咖啡因(caffeine)緊實乳霜之抗老化(Anti-aging)有效性(Efficacy)。自製乳霜黏度為2272.7cP,屬於不油膩延展性霜體。六位受試者(20-22歲女性)每日兩次塗抹緊實乳霜於上臂內側皮膚,四週使用前後以彈力測定儀測得皮膚彈力參數(R2),有顯著差異(P<0.01),顯示咖啡因緊實霜有效改善皮膚彈性。由皮膚地形顯微影像計算皺紋度參數(Rm、Volume),發現緊實霜與安慰劑再塗抹四週前後皆無顯著差異(P<0.5)。顯示緊實乳霜並無明顯一致改善所有受試者皮膚皺紋度之效果。但單獨檢視個別受試者數據可發現,C受試者的皺紋參數(SEr),在使用緊實乳霜後改善率為49%,說明化妝品對不同個體的適用性有很大差異。可知以光電儀器評估產品有效性,對配方開發、功效驗證與市場行銷都具高度價值。擴大受試樣本數、要求受試者依指示使用樣品及降低環境變數,都能提升評估之代表性。
Effect on skin elasticity and roughness are important criteria during the development of novel antiaging cosmetic formulations. This study focuses on the in vivo performance of a self-made caffeine firming cream. Influences on skin properties were investigated with noninvasive validated devices (Cutometer Sem 575 and Visioscan VC 98). Six women aged 20-22 years participated in a placebo-controlled trial. After an application period of 4 weeks, statistically significant change in skin elasticity was detected, compared with placebo (p< 0.01). Skin roughness, as evaluated by three-dimensional micro-topography imaging, remained almost unchanged, which is attributed to the young age of the volunteers. A further improvement of their skin roughness would not be desirable. Older patient panel will be needed to visualize this effect in our further study.