Institute of Pharmaceutics and Biopharmaceutics, Heinrich-Heine-University, Universitaetsstr. 1, 40225, Duesseldorf, Germany.
AAPS PharmSciTech. 2013 Mar;14(1):402-11. doi: 10.1208/s12249-013-9925-5. Epub 2013 Jan 25.
Coating of solid dosage forms is an important unit operation in the pharmaceutical industry. In recent years, numerical simulations of drug manufacturing processes have been gaining interest as process analytical technology tools. The discrete element method (DEM) in particular is suitable to model tablet-coating processes. For the development of accurate simulations, information on the material properties of the tablets is required. In this study, the mechanical parameters Young's modulus, coefficient of restitution (CoR), and coefficients of friction (CoF) of gastrointestinal therapeutic systems (GITS) and of active-coated GITS were measured experimentally. The dynamic angle of repose of these tablets in a drum coater was investigated to revise the CoF. The resulting values were used as input data in DEM simulations to compare simulation and experiment. A mean value of Young's modulus of 31.9 MPa was determined by the uniaxial compression test. The CoR was found to be 0.78. For both tablet-steel and tablet-tablet friction, active-coated GITS showed a higher CoF compared with GITS. According to the values of the dynamic angle of repose, the CoF was adjusted to obtain consistent tablet motion in the simulation and in the experiment. On the basis of this experimental characterization, mechanical parameters are integrated into DEM simulation programs to perform numerical analysis of coating processes.
固体制剂包衣是制药行业中的一个重要单元操作。近年来，作为过程分析技术工具，药物制造过程的数值模拟越来越受到关注。离散元法（DEM）特别适合于模拟片剂包衣过程。为了进行准确的模拟，需要了解片剂的材料特性信息。在这项研究中，我们通过实验测量了胃肠道治疗系统（GITS）和活性包衣 GITS 的机械参数，包括杨氏模量、恢复系数（CoR）和摩擦系数（CoF）。我们还研究了这些片剂在鼓式包衣机中的动态安息角，以修正 CoF。所得值被用作 DEM 模拟的输入数据，以比较模拟和实验。单轴压缩试验确定杨氏模量的平均值为 31.9 MPa。CoR 为 0.78。对于片剂-钢和片剂-片剂之间的摩擦，活性包衣 GITS 的 CoF 均高于 GITS。根据动态安息角的值，我们调整了 CoF，以在模拟和实验中获得一致的片剂运动。在此实验特性化的基础上，我们将机械参数集成到 DEM 模拟程序中，以对包衣过程进行数值分析。
