The present study investigates simultaneous release of two hydrophobic contraceptive steroids from core-shell fibers made by coaxial electrospinning. The contraceptive steroids levonorgestrel (LNG) and ethinylestradiol (EE) were incorporated in gelatin/poly(ε-caprolactone) (PCL) core-shell fibers. The influence of shell concentration and core feed/flow rate (ml/h) on the physical, chemical, mechanical and release properties of drug incorporated coaxial fibers were evaluated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, universal testing machine (UTM) and highperformance liquid chromatography (HPLC). SEM results revealed the influence of feed/flow rate on pore size (in the range 586–1036 nm) and fiber diameter (i.e. 621–1650 nm) of the coaxial fibers. TEM analysis confirmed the presence of core-shell morphology. DSC results conferred that drugs were in an amorphous form within core-shell fibers. The FT-IR spectra established the drug encapsulation by the electrospinning process. Swelling studies demonstrate that increasing the shell (PCL) concentration i.e. 4–10% w/v decreases the swelling ratio (295–140%). The drugs release kinetics satisfactorily described by first-order (R²>0.95) model and Korsmeyer-Peppas model (R²≥0.95) for all the prepared core-shell formulations. These formulations were found to follow anomalous non-Fickian transport, which suggests that the drug release is controlled by both diffusion and erosion of polymer matrix. These results clearly demonstrate that it is possible to control the release rate for the two hydrophobic (contraceptive) drugs through coaxial electrospinning process for the first time to the best of our knowledge.

本研究研究了从同轴电纺丝制成的核壳纤维中同时释放两种疏水性避孕类固醇。将避孕药甾体左炔诺孕酮（LNG）和炔雌醇（EE）掺入明胶/聚（ε-己内酯）（PCL）核-壳纤维中。壳浓度和堆芯进料/流速（ml）的影响/ h），使用扫描电子显微镜（SEM），透射电子显微镜（TEM），差示扫描量热法（DSC），傅里叶变换红外（FT-IR）对掺入药物的同轴纤维的物理，化学，机械和释放性能进行评估光谱学，通用测试机（UTM）和高效液相色谱（HPLC）。SEM结果表明进料/流速对同轴纤维的孔径（在586-1036 nm范围内）和纤维直径（即621-1650 nm）的影响。TEM分析证实了核-壳形态的存在。DSC结果表明药物在核-壳纤维内呈无定形形式。FT-IR光谱通过电纺丝过程建立了药物包封。溶胀研究表明，增加壳（PCL）浓度即 w / v的4–10％降低了溶胀率（295–140％）。药物释放动力学令人满意地由一阶（R² > 0.95）模型和Korsmeyer-Peppas模型（R ²为所有的制备的芯-壳制剂≥0.95）。发现这些制剂遵循非Fickian异常运输，这表明药物释放受聚合物基质的扩散和侵蚀控制。这些结果清楚地表明，就我们所知，这是第一次可以通过同轴电纺丝工艺控制两种疏水性（避孕）药物的释放速率。