Fujimori Junya, Yonemochi Etsuo, Fukuoka Eihei, Terada Katsuhide
Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Chiba, Japan.
Chem Pharm Bull (Tokyo). 2002 Mar;50(3):408-12. doi: 10.1248/cpb.50.408.
In order to develop the polymer materials having temperature-sensitive and high biological safety, Eudragit RS-PO and polyethylene glycol 400 (PEG 400) blend polymers (EPG) were prepared. The EPGs that have the glass transition temperature (Tg) at around the body temperature were prepared by the addition of 5--13% PEG 400 to Eudragit RS. As glassy polymers are not in thermodynamic equilibrium below their Tg, the effects of isothermal aging on the T(g)s of Eudragit RS and EPG containing 10% PEG 400 (10% EPG) were also studied at various aging temperatures. The Tg values of Eudragit RS increased with the aging time and after 30 d of aging, they apparently reached constant values which markedly differed depending on the aging temperatures. On the other hand, the Tg values of 10% EPG were almost independent of the aging temperature and reached around 33 degrees C at 30 d after aging. The ability as thermo-sensitive polymer of EPG was evaluated by the dissolution test of the acetaminophen (AAP) matrix tablets prepared with EPG. The AAP release rate from the EPG matrix tablets slightly changed below the Tg of tablets, and then, it markedly increased above the Tg. Considering high biological safety of Eudragit RS and PEG 400, EPG might be available to develop the novel thermo-sensitive drug delivery systems.
为了开发具有温度敏感性和高生物安全性的聚合物材料，制备了聚丙烯酸树脂RS-PO与聚乙二醇400（PEG 400）的共混聚合物（EPG）。通过向聚丙烯酸树脂RS中添加5%-13%的PEG 400，制备出玻璃化转变温度（Tg）在体温附近的EPG。由于玻璃态聚合物在其Tg以下处于非热力学平衡状态，因此还研究了在不同老化温度下等温老化对聚丙烯酸树脂RS和含10% PEG 400的EPG（10% EPG）的Tg的影响。聚丙烯酸树脂RS的Tg值随老化时间增加，老化30天后，它们明显达到恒定值，且这些值因老化温度的不同而有显著差异。另一方面，10% EPG的Tg值几乎与老化温度无关，老化30天后达到约33℃。通过对用EPG制备的对乙酰氨基酚（AAP）骨架片进行溶出试验，评估了EPG作为热敏聚合物的性能。AAP从EPG骨架片中的释放速率在片剂Tg以下略有变化，然后在Tg以上显著增加。考虑到聚丙烯酸树脂RS和PEG 400具有较高的生物安全性，EPG可能可用于开发新型热敏药物递送系统。
