Joung Yoon Ki, Choi Jong Hoon, Park Kyung Min, Park Ki Dong
Department of Molecular Science and Technology, Ajou University, 5 Wonchon, Yeoungtong, Suwon 443-749, Korea.
Biomed Mater. 2007 Dec;2(4):269-73. doi: 10.1088/1748-6041/2/4/010. Epub 2007 Nov 2.
The release profile of a hydrophobic drug, indomethacin (IMC), from poly(lactic-co-glycolic acid) (PLGA) particles embedded in a chitosan-Pluronic (CP) hydrogel matrix was investigated. The PLGA particles were prepared by an oil-in-water (O/W) emulsion method, and were mixed with IMC. The average diameter of the prepared PLGA particles was determined as 41.6 +/- 35.8 microm by dynamic light scattering (DLS). The loading amount and loading efficiency were 0.023 +/- 0.01 mg/mg and 14.8 +/- 0.67%, respectively. The CP solution (16 wt%) was transformed into a thermosensitive hydrogel under increasing temperature above a lower critical solution temperature (LCST). In this process, the IMC-loaded PLGA particles were mixed and uniformly dispersed in the solution phase, following thermosensitive gelation. SEM observation revealed that the added IMC-loaded PLGA particles were uniformly dispersed in a three-dimensional matrix of the CP hydrogel, observed by SEM. The PLGA particles embedded in the CP hydrogel released about 30% of loaded IMC for 25 days, showing a significantly sustained release as compared with the PLGA particles only (approximately 50% for the same period). Therefore, it is assumed that this sustained release of IMC results from the retardation effect of the CP hydrogel matrix on the degradation and release of the PLGA particles.
研究了包埋于壳聚糖-普朗尼克（CP）水凝胶基质中的聚乳酸-乙醇酸共聚物（PLGA）颗粒对疏水性药物吲哚美辛（IMC）的释放特性。采用水包油（O/W）乳液法制备PLGA颗粒，并将其与IMC混合。通过动态光散射（DLS）测定所制备PLGA颗粒的平均直径为41.6±35.8微米。载药量和载药效率分别为0.023±0.01毫克/毫克和14.8±0.67%。在温度升高至低于临界溶液温度（LCST）以上时，CP溶液（16重量%）转变为热敏水凝胶。在此过程中，载IMC的PLGA颗粒在溶液相中混合并均匀分散，随后发生热敏凝胶化。扫描电子显微镜（SEM）观察显示，通过SEM观察到添加的载IMC的PLGA颗粒均匀分散在CP水凝胶的三维基质中。包埋于CP水凝胶中的PLGA颗粒在25天内释放了约30%的载药量IMC，与仅PLGA颗粒相比（同期约为50%）显示出显著的缓释效果。因此，推测IMC的这种缓释是由于CP水凝胶基质对PLGA颗粒降解和释放的阻滞作用所致。
