Therapeutics Research Centre, School of Medicine, Princess Alexandra Hospital, University of Queensland, Woolloongabba, Qld 4102, Australia.
Int J Cosmet Sci. 2012 Dec;34(6):525-35. doi: 10.1111/ics.12001. Epub 2012 Oct 11.
Twenty products, containing a radiolabelled form of each active in typical cosmetic formulations, were made and applied to female human epidermal membranes mounted in Franz diffusion cells for 48 h under 'in use' conditions. The products consisted of combinations of five formulations (a hydro-alcoholic gel, an oil in water emulsion, a water in oil emulsion, a microemulsion and an oil) with four model drug actives (testosterone, hydrocortisone, 5-fluorouracil and ketoconazole). Steady-state flux appeared to be reached by 8 h and maintained for all products, other than for the microemulsions, consistent with the actives being present in the residual formulation on the skin at saturation. The recovery for each active at the end of the 48-h study (from a series of stratum corneum tape strips, the remaining skin, cumulative amount penetrating into the receptor solution, product washed from the skin and on the donor chamber cap) ranged from 86.5% to 100.6%. The rank order of the fluxes for the actives from the hydro-alcoholic gel is consistent with the known active molecular size and polarity determinants for maximum epidermal flux. Actives with similar steady-state (maximum) fluxes from a range of formulations had retention in the stratum corneum and similar transport rate constants through the stratum corneum. The microemulsion formulation significantly enhanced both the stratum corneum steady-state flux and transport rate constant for 5-fluorouracil, hydrocortisone and testosterone. The penetration flux of each active could be related to its size and polarity and appeared maximal when the actives in the different cosmetic formulations applied to the skin under 'in use' conditions were likely to remain in the residual product on the skin as a saturated solution after solvent evaporation. Enhanced penetration fluxes can be achieved by formulation selection and an appropriate choice/mix of emollients/adjuvants. The principles described here provide a framework for understanding the delivery of cosmetic ingredients from various formulations.
二十种产品，每种产品都包含一种放射性标记的活性成分，以典型的化妆品配方制成，并应用于贴附在 Franz 扩散细胞中的女性人类表皮膜，在“使用中”条件下进行 48 小时的实验。这些产品由五种配方（水醇凝胶、水包油乳剂、油包水乳剂、微乳液和油）与四种模型药物活性成分（睾酮、氢化可的松、5-氟尿嘧啶和酮康唑）组成。稳态通量似乎在 8 小时内达到，并在所有产品中保持稳定，除了微乳液外，这与活性成分在皮肤的残留配方中达到饱和时一致。在 48 小时研究结束时，每种活性成分的回收率（从一系列角质层胶带、剩余皮肤、渗透到受体溶液中的累积量、从皮肤和供体室盖上洗掉的产品）在 86.5%至 100.6%之间。从水醇凝胶中，活性成分的通量顺序与已知的活性分子大小和极性决定因素一致，这些因素决定了最大的表皮通量。从一系列配方中获得相似稳态（最大）通量的活性成分，在角质层中的保留率和通过角质层的相似传输速率常数。微乳液配方显著增强了 5-氟尿嘧啶、氢化可的松和睾酮的角质层稳态通量和传输速率常数。每种活性成分的渗透通量与其大小和极性有关，当在“使用中”条件下应用于皮肤的不同化妆品配方中的活性成分在溶剂蒸发后可能作为残留产品在皮肤中保持饱和溶液时，其渗透通量似乎最大。通过配方选择和适当选择/混合赋形剂/助剂，可以实现增强的渗透通量。这里描述的原理为理解各种配方中化妆品成分的输送提供了一个框架。
