Department of Pharmaceutical Technology and Biopharmaceutics, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
Department of Pharmaceutics and Social Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
Eur J Pharm Biopharm. 2018 Jun;127:260-269. doi: 10.1016/j.ejpb.2018.02.037. Epub 2018 Mar 6.
Deficiency or altered composition of stratum corneum (SC) lipids such as ceramides (CERs), causing skin barrier dysfunction and skin dryness, have been associated with skin diseases such as atopic dermatitis and psoriasis, and ageing. Replenishing the depleted native CERs with exogenous CERs has also been shown to have beneficial effects in restoring the skin barrier. Phyto-derived CERs such as oat CERs were shown to be potential for skin barrier reinforcement. To effect this, however, the oat CERs should overcome the SC barrier and delivered deep into the lipid matrix using the various novel formulations. In an attempt to demonstrate the potential use of oat CERs, lecithin-based microemulsions (MEs) and starch-based nanoparticles (NPs) were formulated and characterized. Besides, ME gel and NP gel were also prepared using Carbopol®980 as a gelling agent. The in vitro release and penetration (using artificial four-layer membrane system) and ex vivo permeation (using excised human skin) of oat CERs from the various formulations were investigated. The results revealed ME enhanced the in vitro release and penetration oat CERs compared to the other formulations. On the other hand, the NPs retarded the release of oat CERs and small quantities of oat CERs incorporated into NP gel penetrated into the deeper layers of the multilayer membranes. The penetration-enhancing effect of ME was also observed in the ex vivo permeation studies where significant quantities of oat CERs were found in the acceptor compartment. Compared to the ME, the ME gel exhibited reduced depth and extent of oat CERs permeation. As compared to NP gel, ME gel enhanced the degree of permeation of oat CERs into the deeper layer of the skin. Generally the gel formulations were effective in concentrating oat CERs in the SC where they are needed to be.
角质层（SC）脂质（如神经酰胺，CERs）的缺乏或组成改变，导致皮肤屏障功能障碍和皮肤干燥，与特应性皮炎、银屑病和衰老等皮肤疾病有关。用外源性 CERs 补充耗尽的天然 CERs，也已被证明对恢复皮肤屏障具有有益作用。植物源性 CERs 如燕麦 CERs 被证明具有增强皮肤屏障的潜力。然而，为了实现这一目标，燕麦 CERs 应该克服 SC 屏障，并使用各种新型制剂输送到脂质基质深处。为了证明燕麦 CERs 的潜在用途，制备并表征了基于卵磷脂的微乳液（MEs）和基于淀粉的纳米颗粒（NPs）。此外，还使用 Carbopol®980 作为胶凝剂制备了 ME 凝胶和 NP 凝胶。研究了各种制剂中燕麦 CERs 的体外释放和渗透（使用人工四层膜系统）和体外渗透（使用离体人皮肤）。结果表明，与其他制剂相比，ME 增强了体外释放和渗透燕麦 CERs。另一方面，NPs 延迟了燕麦 CERs 的释放，并且少量的燕麦 CERs 掺入到 NP 凝胶中渗透到多层膜的较深层中。在离体渗透研究中也观察到 ME 的渗透增强作用，在接受器隔室中发现了大量的燕麦 CERs。与 ME 相比，ME 凝胶表现出减少的燕麦 CERs 渗透深度和程度。与 NP 凝胶相比，ME 凝胶增强了燕麦 CERs 渗透到皮肤较深层的程度。一般来说，凝胶制剂有效地将燕麦 CERs 浓缩在需要的 SC 中。
