Department of Pharmaceutical Sciences, University of Pisa, Pisa, Italy.
Eur J Pharm Biopharm. 2010 Nov;76(3):443-9. doi: 10.1016/j.ejpb.2010.08.004. Epub 2010 Sep 9.
In this investigation two vitamin C-based -6-O-ascorbic acid esters (ASC₁₂ and ASC₁₆), able to form liquid-crystal structures (coagels) was evaluated for their potential usefulness to promote the permeation and distribution of ibuprofen (IBU). Two coagel formulations and the same coagels added of polyethylene glycol (PEG-400) were assayed in comparison with a commercial product (Arfen®) by using hairless rat skin as model. The ASC₁₆ and ASC₁₂ derivatives gave rise to stable supramolecular assemblies in water and in water/PEG mixtures (coagels), allowing the solubilization of IBU (0.85%) and producing a IBU controlled release systems, as evidenced by the dynamic dialyse test: the n values were near 1.0, indicative of a linear kinetic, for all coagel formulations, except for the ASC₁₂PEG/C formulation (n=1.51). Our results evidenced the enhancement activity of coagels and the synergic effect of the combination with PEG: all coagels showed a higher amount of IBU permeated through the skin compared to commercial Arfen® with an enhancement factor of 52.94 and 21.53 for ASC₁₂PEG/C and ASC₁₆/C respectively. Otherwise, coagels formulations appeared to produce a low IBU depot in the skin and in the same order of magnitude in epidermis and derma, in spite of significant increase of IBU cutaneous permeation. The positive synergic effect of the coagel-PEG mixtures was demonstrated by the high amount of IBU accumulated in the upper skin layers. The effect of the coagels on the IBU skin permeation and distribution depending on their hydro-lipophilic character could allow a rational design and an optimization of topical formulations.
在这项研究中,评估了两种基于维生素 C 的 -6-O-抗坏血酸酯(ASC₁₂ 和 ASC₁₆)作为潜在的有用物质,以促进布洛芬(IBU)的渗透和分布。将两种凝聚胶体制剂和相同的凝聚胶体制剂添加聚乙二醇(PEG-400)与商业产品(Arfen®)进行比较,使用无毛大鼠皮肤作为模型。ASC₁₆和 ASC₁₂ 衍生物在水中和水/PEG 混合物(凝聚胶)中产生稳定的超分子组装,允许 IBU(0.85%)溶解,并产生 IBU 控制释放系统,这可以通过动态透析试验证明:对于所有凝聚胶制剂,n 值接近 1.0,表明是线性动力学,除了 ASC₁₂PEG/C 制剂(n=1.51)。我们的结果表明凝聚胶的增强活性和与 PEG 结合的协同效应:与商业 Arfen®相比,所有凝聚胶都显示出更多的 IBU 渗透穿过皮肤,增强因子分别为 52.94 和 21.53,对于 ASC₁₂PEG/C 和 ASC₁₆/C 制剂。然而,尽管 IBU 皮肤渗透显著增加,凝聚胶制剂似乎在皮肤中产生了低 IBU 库,在表皮和真皮中也处于相同的数量级。凝聚胶-PEG 混合物的正协同效应通过在上层皮肤中积累的大量 IBU 得到证明。凝聚胶对 IBU 皮肤渗透和分布的影响取决于其亲水亲脂特性,可以允许对局部制剂进行合理设计和优化。