壳聚糖-明胶体系的温敏凝胶及其药物缓释性能

Thermosensitive hydrogel based on chitosan-gelatin and used for sustained drug release in vitro

用试管倒置法研究在甘油磷酸钠存在下,壳聚糖-明胶体系的温敏凝胶化性能。体系3组分的体积比V(壳聚糖)∶V(G)∶V(甘油磷酸钠)从10∶0.5∶1～10∶0.5∶2.5(体系pH值6.8),37℃下凝胶化时间由(1200±60)s降至150s;V(壳聚糖)∶V(G)∶V(甘油磷酸钠)体积比从10∶0.25∶2～10∶1.25∶2(体系pH值6.8),37℃下凝胶化时间从(300±10)s增至(690±30)s。固定三者体积配比,明胶浓度增大,37℃下凝胶化时间延长。pH值在6.8～7.2范围适合于体系凝胶化。调节体积配比及合适的pH值,可实现壳聚糖/明胶/甘油磷酸钠体系在37℃下快速凝胶化。以布洛芬为模型药物,24h载药温敏凝胶累积释放度为(79.28±2.0)%,而24h布洛芬原药累积释放度为(97.04±2.5)%,表明载药凝胶对药物具有缓释作用。

Using the method of inversion of test tube, temperature sensitivity of chitosan/gelatin/glycerphosphate hydrogel was studied under different ratio of chitosan and gelatin and glycerphosphate （V/V/V） at various pH of the mixture solutions. The gelation time （GT） of chitosan/gelatin/glycerphosphate hydrogel was decreased from （1200±60）s to 150s at the condition of 37℃ and pH6 . 8 when the ratio in volume of chitosan/gelatin/glycerphosphate from 10 ： 0. 5 ： 1 to 10 ： 0.5 ： 2.5. The GT was increased from （300±10）s to 690s when the volume ratio of chitosan/gelatin/glycerphosphate was changed from 10 ： 0.25 ： 2 to 10 ： 1.25 ： 2 at the condition of 37℃ and pH 6.8. Fixed volume ratio, high concentration of gelatin result to longer gelation time at 37℃. The suitable pH to gelate for chitosan/gelatin/glycerphosphate system was at 6.8-7.2. This system could rapidly be gelated at 37 ℃ under the appropriate volume ratio of chitosan/gelatin/glyeerphosphate and pH. Ibu- profen as model drugs loaded in the thermosensitive hydrogel, the in vitro dissolution showed that the cumulative release at 24h of ibuprofen loaded in chitosan/gelatin/glycerphosphate hydrogel was （79. 28 ± 2. 0） %, which was significantly lower than that of raw ibuprofen for （97.04±2. 5）%. Thermosensitive hydrogel incorporating drug showed more significant sustained release, and can be a good potential drug carrier for temperature sensitive and sustained drug delivery system.