Electrospun nanofibers are promising drug delivery systems for transdermal applications with a release rate of the drug depending on the host polymer used. However, it is still a challenge to control (i.e., reduce) the release rate for hydrophilic drugs in order to provide long-term sustained release. In this study, we aimed to produce controlled release nanofibers to achieve long term drug release for transdermal applications. Pramipexole, which requires multiple doses per day, was selected as a hydrophilic model drug molecule and was electrospun with hydrophobic polycaprolactone polymer. To prevent burst release of the drug and provide a long-term release profile, nanofibers were coated with Parylene C or N using a chemical vapor deposition process. The effective thickness of nanofibers increased with the amount of Parylene coating. Parylene coating also enhanced the mechanical properties and hydrophobicity but decreased the bioadhesion values. Drug release and diffusion studies showed that Parylene coating successfully prevents drug burst release. Uncoated nanofibers completely released pramipexole within 12 h. A relatively low amount of Parylene N and C coating provided 81% and 52% drug release over 10 days, while increased Parylene N and C coating resulted in 27% and 12.6% drug release over a 30-day period, respectively. Parylene coating process offers the possibility of long-term controlled release kinetics including hydrophilic drugs.

电纺纳米纤维是用于透皮应用的有前途的药物输送系统，其药物的释放速率取决于所用的宿主聚合物。但是，控制仍然是一个挑战（即（降低）亲水性药物的释放速率，以提供长期的持续释放。在这项研究中，我们旨在生产控释纳米纤维，以实现透皮应用的长期药物释放。每天需要多次剂量的普拉克索被选作亲水模型药物分子，并与疏水性聚己内酯聚合物进行静电纺丝。为了防止药物的突然释放并提供长期释放特性，使用化学气相沉积工艺将纳米纤维用聚对二甲苯C或N包覆。纳米纤维的有效厚度随聚对二甲苯涂层的量而增加。聚对二甲苯涂层还增强了机械性能和疏水性，但降低了生物粘附值。药物释放和扩散研究表明，聚对二甲苯涂层成功地阻止了药物的突然释放。未涂覆的纳米纤维在12小时内完全释放出普拉克索。相对较低的聚对二甲苯N和C涂层在10天内可释放81％和52％的药物，而增加的聚对二甲苯N和C涂层可在30天内释放27％和12.6％的药物。聚对二甲苯涂层工艺提供了包括亲水性药物在内的长期控释动力学的可能性。