Zhao Yue, Chen Wenna, Cai Qing, Wang Shenguo, Bo Jun, Wu Chi
The Open Laboratory of Bond-selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Macromol Biosci. 2004 Mar 15;4(3):308-13. doi: 10.1002/mabi.200300061.
The microphase inversion of water-insoluble poly(L-lactide), "poly[(L-lactide)-co-glycolide] and polylactide-block-poly(ethylene oxide)-block-polylactide from THF to water can result in narrowly distributed stable particles. Gliclazide, a commercial drug, can be encapsulated inside during the process. The formation and degradation of such particles was studied by laser light scattering. In comparison with the corrosion of a bulk material, the degradation of each particle is so fast that we only detect the decrease of the particle number, not the corrosion of individual particles. Therefore, the degradation is a "one-by-one" random process, just like the chemical reaction of molecules in solution. The disappearing rate of the particle number is nearly independent of time, ideal for the controlled release of drugs encapsulated inside. The amount of encapsulated gliclazide depends on the copolymer's hydrophobicity (composition), while the releasing rate mainly is, directly related to the disappearing rate of the particles. The correlation between the fluorescence intensity and the degradation was used to study the kinetics of gliclazide releasing. The releasing pattern is controllable with a proper choice of the drug loading, copolymer composition, pH and temperature.
水不溶性聚（L-丙交酯）、聚[（L-丙交酯）-共-乙交酯]以及聚丙交酯-嵌段-聚（环氧乙烷）-嵌段-聚丙交酯从四氢呋喃到水的微相转变可产生分布狭窄的稳定颗粒。商业药物格列齐特在该过程中可被包封在内部。通过激光散射研究了此类颗粒的形成与降解。与块状材料的腐蚀相比，每个颗粒的降解速度极快，以至于我们只能检测到颗粒数量的减少，而无法检测到单个颗粒的腐蚀。因此，降解是一个“逐个”的随机过程，就如同溶液中分子的化学反应。颗粒数量的消失速率几乎与时间无关，这对于包封在内部的药物的控释来说非常理想。包封的格列齐特的量取决于共聚物的疏水性（组成），而释放速率主要直接与颗粒的消失速率相关。利用荧光强度与降解之间的相关性来研究格列齐特释放的动力学。通过适当选择药物载量、共聚物组成、pH值和温度，释放模式是可控的。
