EFFECT OF TEMPERATURE ON MECHANISMS OF DRUG-RELEASE AND MATRIX DEGRADATION OF POLY(D,L-LACTIDE) MICROSPHERES
EFFECT OF TEMPERATURE ON MECHANISMS OF DRUG-RELEASE AND MATRIX DEGRADATION OF POLY(D,L-LACTIDE) MICROSPHERES
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DOI：
10.1016/0168-3659(94)90248-8
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发表时间：
1994-08-01
影响因子：
10.8
通讯作者：
TERAO, T
中科院分区：
文献类型：
--
作者：
ASO, Y;YOSHIOKA, S;TERAO, T
研究了不同玻璃化转变温度（Tg）的聚（D，L-乳酸）微球在不同温度下的药物释放和基质降解，以阐明温度对药物释放和基质降解机制的影响。当温度高于Tg时，聚合物的平均分子量在药物释放过程中显著降低。孕酮的释放速度快于微球的重量损失，并且可以拟合Higuchi方程。这些结果表明，在高于T-g的温度下，从基质本体的扩散有助于药物释放。相比之下，在低于微球的Tg的温度下，聚合物的平均分子量在整个实验期间没有变化，并且基质降解仅限于基质表面。孕酮的释放主要是由于表面侵蚀。这些结果表明，即使在聚丙交酯的情况下，药物释放只能通过表面侵蚀来控制。
Drug release and matrix degradation of poly (D,L-lactide) microspheres with different glass transition temperatures (T-g) were investigated at various temperatures in order to clarify the effect of temperature on mechanisms of drug release and matrix degradation. At temperatures above T-g, the average molecular weight of the polymer decreased markedly during drug release. Progesterone release was faster than microsphere weight loss, and could be fitted to the Higuchi equation. These results suggest that diffusion from the bulk of the matrix contributed to drug release at temperatures above T-g. In contrast, at temperatures below the T-g of the microspheres, the average molecular weight of the polymer did not change throughout the experimental period and matrix degradation was restricted to the matrix surface. Release of progesterone was due mainly to surface erosion. These results suggest that, even in the case of polylactide, drug release can be controlled only by surface erosion.