Jeong Jong-Cheol, Lee Jaeyoung, Cho Kilwon
Department of Chemical Engineering, School of Environmental Engineering, Polymer Research Institute, Pohang University of Science and Technology, Pohang 790-784, South Korea.
J Control Release. 2003 Oct 30;92(3):249-58. doi: 10.1016/s0168-3659(03)00367-5.
This study investigates the release behavior of papaverine from poly(epsilon-caprolactone) (PCL) microparticles prepared by the oil/water solvent evaporation method. Microparticles were characterized in terms of crystalline morphology, size, drug loading, and encapsulation efficiency by using differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), scanning electron microscopy (SEM), and UV spectrometry. The release behavior of papaverine was governed by the microstructure of PCL microparticles, suggesting that the environment for diffusion changes according to processing conditions such as polymer solution concentration, thermal history, and polymer molecular weight. As the PCL solution concentration increased, the drug release behavior showed a more sustained pattern. This result indicates that the size of the PCL microparticles is a determining factor for drug release. And when higher PCL molecular weight is used for preparation of microparticles, it led to a rapid release. Furthermore, a more delayed pattern of drug release profile was obtained in the sample prepared with higher thermal treatment. These results suggest that the crystalline microstructure of PCL microparticles plays an important role in its drug release behavior.
本研究考察了通过油/水溶剂蒸发法制备的聚（ε-己内酯）（PCL）微粒中罂粟碱的释放行为。通过差示扫描量热法（DSC）、小角X射线散射（SAXS）、扫描电子显微镜（SEM）和紫外光谱法对微粒的晶体形态、尺寸、载药量和包封率进行了表征。罂粟碱的释放行为受PCL微粒微观结构的控制，这表明扩散环境会根据诸如聚合物溶液浓度、热历史和聚合物分子量等加工条件而变化。随着PCL溶液浓度的增加，药物释放行为呈现出更持久的模式。该结果表明PCL微粒的尺寸是药物释放的一个决定性因素。并且当使用更高分子量的PCL制备微粒时，会导致快速释放。此外，在经过更高热处理制备的样品中获得了更延迟的药物释放曲线模式。这些结果表明PCL微粒的晶体微观结构在其药物释放行为中起重要作用。
