In this study, oregano essential oil (OEO) has been encapsulated in chitosan nanoparticles by a two-step method, i.e., oil-in-water emulsion and ionic gelation of chitosan with sodium tripolyphosphate (TPP). The success of OEO encapsulation was confirmed by Fourier transform infrared (FT-IR) spectroscopy, UV-vis spectrophotometry, thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques. The obtained nanoparticles exhibited a regular distribution and spherical shape with size range of 40-80 nm as observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). As determined by TGA technique, the encapsulation efficiency (EE) and loading capacity (LC) of OEO-loaded chitosan nanoparticles were about 21-47% and 3-8%, respectively, when the initial OEO content was 0.1-0.8 g/g chitosan. In vitro release studies showed an initial burst effect and followed by a slow drug release.

中文翻译：

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牛至精油在壳聚糖纳米粒子中的包囊两步法：制备，表征和体外释放研究。

在这项研究中，牛至精油（OEO）已通过两步法封装在壳聚糖纳米颗粒中，即水包油乳液和壳聚糖与三聚磷酸钠（TPP）的离子凝胶化。傅立叶变换红外（FT-IR）光谱，紫外可见分光光度法，热重分析（TGA）和X射线衍射（XRD）技术证实了OEO封装的成功。通过扫描电子显微镜（SEM）和原子力显微镜（AFM）观察到，所获得的纳米颗粒表现出规则分布和球形，尺寸范围为40-80nm。通过TGA技术确定，当初始OEO含量为0.1-0.8 g / g时，载有OEO的壳聚糖纳米颗粒的包封效率（EE）和载量（LC）分别为约21-47％和3-8％。壳聚糖。