Kinetic and thermodynamic modeling of the formation of polymeric microspheres using solvent extraction/evaporation method
Kinetic and thermodynamic modeling of the formation of polymeric microspheres using solvent extraction/evaporation method
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DOI：
10.1016/0168-3659(95)00077-1
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发表时间：
1995-12-01
影响因子：
10.8
通讯作者：
DeLuca, PP
中科院分区：
文献类型：
--
作者：
Li, WI;Anderson, KW;DeLuca, PP
采用溶剂萃取/挥发法制备肽的聚乳酸-乙交酯共聚物微球涉及到内变量，如溶剂-聚合物相互作用参数，外变量，如分散相/连续相比例，温度和分散相组成。通过引入这些变量，建立了基于传质的数学模型，并将该模型与相变状态相叠加，用于预测微球的性质。分散相内的传质基于扩散理论，是化学势梯度驱动力和传质参数的函数。溶剂去除过程包括溶剂从分散相扩散出来，然后在连续相/空气界面蒸发，这一过程可以通过强制对流来促进。在数学上，该过程可以通过耦合分散相传质方程和连续相一级蒸发方程来表示。用粘性界面和玻璃性界面两个相变来表示聚合物溶液中的相变。相变可以叠加在分散相的成分分布上，通过这种处理可以评价微球的固化情况。
The formation of polylactide-co-glycolide microspheres loaded with a peptide using solvent extraction/evaporation methods involves intrinsic variables, such as solvent-polymer interaction parameters, and extrinsic variables, such as dispersed phase/continuous phase ratio, temperature and dispersed phase composition. A mathematical model based on mass transfer was developed by incorporating these variables, and, by superimposing with the state of phase transition, the model was used to predict the microsphere properties. The mass transfer in the dispersed phase was based on diffusion theory and was a function of the driving force of chemical potential gradient and transport parameters. The solvent removal process involved solvent diffusion out of the dispersed phase followed by evaporation at the continuous phase/air interface, a process which can be facilitated by forced convective flow. Mathematically, the process can be expressed by coupling the equations for mass transfer in the dispersed phase and first order evaporation from the continuous phase. Two phase transitions, the viscous and glassy boundaries, were used to represent the phase transitions in the polymer solution. The phase transition can be superimposed on the composition profile in the dispersed phase; the solidification of microsphere can be evaluated from such a treatment.