Introduction 최근 서구식 생활방식이나 실내외 환경변화 등으로 자신의 피 부가 민감성 피부(sensitive skin)라고 생각하는 소비자가 많고 이에 대한 연구가 꾸준히 증가하는 추세이다. 한 연구에서 20-40세 피험자 50명을 대상으로 민감성 피부군 20명, 비민감성 피부군 30명을 구분하고 피부장벽기능 및 세라 마이드 함량을 분석한 결과, 민감성 피부군은 측정한 모든 부위 에서 경표피 수분손실량(transepidermal water loss, TEWL)의 차이가 없는 것으로 나타났으나 세라마이드 함량을 분석한 결과 에서는 모든 측정 부위에서 세라마이드가 감소되어 있음을 보였 다. 특히 얼굴 부위에서의 차이는 통계적으로도 유의하거나 뚜렷 하게 나타났다(Cho et al., 2012). 또한 다양한 피부염에서의 세라마이드 함량을 확인한 결과, 겨 울건조증, 접촉피부염, 아토피피부염 등 여러 피부염에서 세라마 이드 총 함량이 감소되어 있음이 보고된바 있다(Coderch

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... t al., Abstract Purpose: We assessed the in vivo efficacy of a cosmetic formulation comprising a transdermal delivery system of model bile acid nanoparticles after the development of a phytosphingosine-1-phosphate (PhS1P)/phytosterol (PS) carrier based on chemically modified lecithin with sodium deoxycholate, using cholesterol as a hydrophobic component. Methods: PhS1P/PS was loaded into a bile acidconjugated nanoparticle (PhS1P/PS-MBA nanoparticle) model via sonication. Franz diffusion cell experiment was performed to evaluate the skin penetration efficacy of the prepared nanoparticles and to comprehend the feasibility of applying the raw material. The nanoparticles were confirmed using a particle size analyzer, scanning electron microscope, and high-performance liquid chromatography system. In order to understand the effectiveness of the nanoparticles on the skin, we performed an in vivo test in human volunteers using the finished product. The elasticity, thickness, and dermal density of the applied skin were examined by using Cutometer (Courage+Khazaka electronic GmbH, Germany). Results: We confirmed through our tests that the nanoparticles could be successfully prepared with 85% yield and were approximately 120.3 nm in diameter. The product showed more efficient skin permeation than the control, thereby suggesting an easier uptake within the cells and a concomitant fast release of cleaved PhS1P/PS into the human skin. Safety assessment, elasticity, thickness, and dermal density of the nanoparticles on the human skin were examined to test the possible applicability of the nanoparticles to cosmetics. No adverse symptoms were observed. Conclusion: It is therefore recommended that cosmetic products should use PhS1P/PS-MBA nanoparticles in their formulation for easier absorbability into the skin. Our experiment confirms that this new material may have valuable influences on the human skin.