Université Paris-Sud, Laboratoire Matériaux et Santé, EA 401, Faculté de pharmacie, 5 rue Jean-Baptiste Clément, 92290 Chatenay-Malabry Cedex, France.
Int J Pharm. 2013 Sep 10;453(2):389-94. doi: 10.1016/j.ijpharm.2013.05.038. Epub 2013 Jun 6.
This work studies the influence of visco-elastic behavior in the finite element method (FEM) modeling of die compaction of pharmaceutical products and how such a visco-elastic behavior may improve the agreement between experimental and simulated compression curves. The modeling of the process was conducted on a pharmaceutical excipient, microcrystalline cellulose (MCC), by using Drucker-Prager cap model coupled with creep behavior in Abaqus(®) software. The experimental data were obtained on a compaction simulator (STYLCAM 200R). The elastic deformation of the press was determined by performing experimental tests on a calibration disk and was introduced in the simulation. Numerical optimization was performed to characterize creep parameters. The use of creep behavior in the simulations clearly improved the agreement between the numerical and experimental compression curves (stresses, thickness), mainly during the unloading part of the compaction cycle. For the first time, it was possible to reproduce numerically the fact that the minimum tablet thickness is not obtained at the maximum compression stress. This study proves that creep behavior must be taken into account when modeling the compaction of pharmaceutical products using FEM methods.
本工作研究了粘弹性行为对药物制剂模压过程有限元方法（FEM）建模的影响，以及这种粘弹性行为如何改善实验和模拟压缩曲线之间的一致性。通过使用 Drucker-Prager 帽模型结合 Abaqus（®）软件中的蠕变行为，对药物赋形剂微晶纤维素（MCC）进行了过程建模。实验数据是在压片机（STYLCAM 200R）上获得的。通过在校准盘上进行实验测试确定了压片机的弹性变形，并将其引入模拟中。进行数值优化以表征蠕变参数。在模拟中使用蠕变行为可明显提高数值和实验压缩曲线（应力、厚度）之间的一致性，尤其是在压缩周期的卸载部分。首次可以数值再现这样一个事实，即片剂的最小厚度不是在最大压缩应力处获得的。这项研究证明，在使用 FEM 方法对药物制剂的压缩进行建模时，必须考虑蠕变行为。
