THE INFLUENCE OF POLYMER GLASS-TRANSITION TEMPERATURE AND MOLECULAR-WEIGHT ON DRUG RELEASE FROM TABLETS CONTAINING POLY(DL-LACTIC ACID)
THE INFLUENCE OF POLYMER GLASS-TRANSITION TEMPERATURE AND MOLECULAR-WEIGHT ON DRUG RELEASE FROM TABLETS CONTAINING POLY(DL-LACTIC ACID)
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DOI：
10.1023/a:1018967424392
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发表时间：
1992-01-01
影响因子：
3.7
通讯作者：
MCGINITY, JW
中科院分区：
文献类型：
--
作者：
OMELCZUK, MO;MCGINITY, JW
使用凝胶渗透色谱、差示扫描量热法和粘度测定法对五种分子量等级的聚（DL-乳酸）进行表征，以确定分子量对玻璃化转变温度和特性粘度的影响。 此外，动态机械热分析通过检测宽温度范围内的运动和结构转变来评估聚合物样品的动态储能模量和阻尼因子。 发现分子量和这些聚合物性能之间存在显着关系。 五个等级的聚（DL-乳酸）也作为粘合剂掺入含有模型药物茶碱和微晶纤维素的骨架片剂配方中。 溶出度研究表明聚合物的性质与片剂的基质释放曲线之间存在显着相关性。 随着聚合物分子量的增加，茶碱的释放逐渐减慢。 当分子量增加到 138,000 时，释放差异变得不那么显着并达到极限渐近值。 此外，利用片剂指数测试来确定聚合物颗粒的压实特性。 尽管与 PLA 的分子量没有相关性，但脆性断裂指数测试表明所有测试颗粒的脆性都非常低。 然而，粘合指数的测定与聚合物的物理机械性能和药物释放曲线密切相关。
Five molecular weight grades of poly(DL-lactic acid) were characterized using gel permeation chromatography, differential scanning calorimetry, and viscometry to determine the effect of molecular weight on the glass transition temperature and the intrinsic viscosity. In addition, dynamic mechanical thermal analysis was used to assess the dynamic storage modulus and the damping factor of the polymer samples by detecting motional and structural transitions over a wide temperature range. Significant relationships were found between the molecular weight and these polymer properties. The five grades of poly(DL-lactic acid) were also incorporated as binders into matrix tablet formulations containing the model drug theophylline and microcrystalline cellulose. Dissolution studies showed significant correlations between the properties of the polymer and the matrix release profiles of the tablets. The release of theophylline slowed down progressively as the polymer molecular weight increased. The differences in release became less significant and reached a limiting asymptotic value as the molecular weight increased to 138,000. Further, tablet index testing was utilized to determine the compaction properties of the polymer granulations. Although there was no correlation with the molecular weight of PLA, brittle fracture index testing indicated very low brittleness for all granulations tested. However, bonding index determinations correlated very well with both the physical-mechanical properties of the polymer and drug release profiles.