Pinnell S R, Yang H, Omar M, Monteiro-Riviere N, DeBuys H V, Walker L C, Wang Y, Levine M
Duke University Medical Center, Department of Medicine, Durham, North Carolina 27707, USA.
Dermatol Surg. 2001 Feb;27(2):137-42. doi: 10.1046/j.1524-4725.2001.00264.x.
Reactive oxygen species generated by ultraviolet light result in photocarcinogenic and photoaging changes in the skin. Antioxidants protect skin from these insults.
This study defines formulation characteristics for delivering L-ascorbic acid into the skin to supplement the skin's natural antioxidant reservoir.
L-ascorbic acid or its derivatives were applied to pig skin. Skin levels of L-ascorbic acid were measured to determine percutaneous delivery.
L-ascorbic acid must be formulated at pH levels less than 3.5 to enter the skin. Maximal concentration for optimal percutaneous absorption was 20%. Tissue levels were saturated after three daily applications; the half-life of tissue disappearance was about 4 days. Derivatives of ascorbic acid including magnesium ascorbyl phosphate, ascorbyl-6-palmitate, and dehydroascorbic acid did not increase skin levels of L-ascorbic acid.
Delivery of topical L-ascorbic acid into the skin is critically dependent on formulation characteristics.
紫外线产生的活性氧会导致皮肤发生光致癌和光老化变化。抗氧化剂可保护皮肤免受这些损伤。
本研究确定将L-抗坏血酸输送到皮肤中以补充皮肤天然抗氧化剂储备的配方特性。
将L-抗坏血酸或其衍生物应用于猪皮。测量皮肤中L-抗坏血酸的水平以确定经皮递送情况。
L-抗坏血酸必须在pH值低于3.5的条件下配制才能进入皮肤。最佳经皮吸收的最大浓度为20%。每日应用三次后组织水平达到饱和；组织消失的半衰期约为4天。抗坏血酸的衍生物，包括磷酸镁抗坏血酸酯、抗坏血酸-6-棕榈酸酯和脱氢抗坏血酸，并未提高皮肤中L-抗坏血酸的水平。
局部L-抗坏血酸向皮肤中的递送严重依赖于配方特性。
