To overcome the constraints presented by the conventional hydrogel-based skin patch, including poor transdermal penetration activity and reluctant release of the encapsulated lipophilic drugs, a facile organogel constituted of amphiphilic hexamethylene diisocyanate (HDI)-based polyurethanes (PUs) was developed in 1,3-propanediol, and the amphiphilic components of poly (ethylene glycol) (PEG) and HDI allow for the formulation of distinctive segregated domains of PEG and HDI based on the inter- and intra-molecular interactions between HDI segments. Of note, a convenient cooling down process allows for the formulation of a stable and homogenous organogel. In addition, a functional host 2,6-dimethyl-β-cyclodextrin (CD) group, acting as a drug reservoir, was included in PEG-HDI, characterized by its gel to sol state transition in the range of 24–36 °C, for the encapsulation of a pharmaceutical compound (norfloxacin), consequently contributing to a minimal drug release profile at 4 °C but an accelerated rate of drug release at physiological temperature. The in vitro drug release and transdermal experimental results show that the organogel as a drug carrier was capable of releasing the drug efficiently, improving the transdermal delivery, and exhibiting bactericidal activity over 80% in vivo. Moreover, the introduced CD moieties could increase the solubility of lipophilic drugs and the dissociation rate in biological milieu, which appears to benefit the promoted drug release rate and transdermal efficiency as compared to a CD-free organogel.

中文翻译：

---

用于诺氟沙星递送的热敏聚氨酯有机凝胶†

为了克服传统的基于水凝胶的皮肤贴片所带来的限制，包括不良的透皮渗透活性和所包封的亲脂性药物的勉强释放，在1中开发了一种由两亲六亚甲基二异氰酸酯（HDI）基聚氨酯（PU）构成的简便有机凝胶。 3-丙二醇以及聚（乙二醇）（HPE）和HDI的两亲性组分可根据HDI链段之间的分子间和分子内相互作用来配制PEG和HDI的独特分隔结构域。值得注意的是，方便的冷却过程允许配制稳定且均质的有机凝胶。此外，PEG-HDI还包含一个功能性的宿主2,6-二甲基-β-环糊精（CD）基团，作为药物储库，其特征在于其在24-36°C范围内的凝胶态至溶胶态转变，用于包封药物化合物（诺氟沙星）的药物，因此有助于在4°C时产生最小的药物释放曲线，但在生理温度下可以加快药物释放速率。这体外药物释放和透皮实验结果表明，有机凝胶作为药物载体能够有效释放药物，改善透皮递送，并在体内具有超过80％的杀菌活性。而且，引入的CD部分可以增加亲脂性药物的溶解度和在生物环境中的解离速率，与不含CD的有机凝胶相比，这似乎有利于提高的药物释放速率和透皮效率。