Polymer Engineering Department, The University of Akron, Akron, OH, 44325, USA.
Chemistry Department, Polymer Research Center, Boğaziçi University, 34342, Bebek, Istanbul, Turkey.
Adv Healthc Mater. 2017 Feb;6(3). doi: 10.1002/adhm.201600775. Epub 2016 Nov 7.
A novel approach to zero-order constant-rate drug delivery from contact lenses is presented. Quasi-Case II non-Fickian transport is achieved by nonuniform drug and diffusivity distributions within three-layer bimodal amphiphilic conetworks (β-APCNs). The center layer is a highly oxygen permeable β-APCN matrix, which contains the drug and exhibits a high drug diffusivity. The outer β-APCN layers contain no-drug and are loaded with vitamin E, which slows diffusion. In contrast to single-layer neat-polymer and vitamin E-loaded films that display first-order "burst" kinetics, it is demonstrated experimentally and by modeling that the combined effect of nonuniform distribution of drug loading and diffusion constants within the three-layer lens maintains low local drug concentration at the lens-fluid interface and yields zero-order drug delivery. The release rates of topical antibiotics provide constant-rate therapeutic-level delivery with appropriate oxygen permeability for at least 30 h, at which time ≈25% of the drug was released.
本文提出了一种从接触镜中实现零级恒速药物释放的新方法。通过在三层双模式两亲性共网络（β-APCNs）内实现非均匀药物和扩散率分布，实现了准案例 II 型非菲克扩散。中心层是一种高透氧性的β-APCN 基质，其中包含药物并具有较高的药物扩散率。外层β-APCN 层不含药物，并且负载有维生素 E，可减缓扩散。与仅含药物的单层纯聚合物和负载有维生素 E 的薄膜相比，实验和模型表明，药物负载和扩散常数在三层透镜内的非均匀分布的综合作用可保持在透镜-液界面处的低局部药物浓度，并实现零级药物释放。局部抗生素的释放速率可提供至少 30 h 的恒定速率治疗水平的药物输送，同时具有适当的氧气透过率，此时约有 25%的药物被释放。
