Challenges in the modeling and prediction of coating of pharmaceutical dosage forms
Challenges in the modeling and prediction of coating of pharmaceutical dosage forms
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DOI：
10.1016/j.powtec.2006.12.006
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发表时间：
2008-02
影响因子：
5.2
通讯作者：
R. Turton
中科院分区：
文献类型：
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作者：
R. Turton
综述了流化床和转鼓设备中涂层质量均匀性的不同建模方法。为了预测涂层质量分布的变异系数（CV），模型必须包括非均匀颗粒运动和/或非均匀喷雾通量的物理特性。包衣过程的描述性模型包括基于更新理论、具有适当群体平衡的房室模型和Monte Carlo模拟的模型。这三种方法给出了合理的拟合实验数据。然而，它们需要调整某些模型参数以获得与实验结果的良好拟合，或者，必须使用广泛的实验程序来评估参数。虽然这些模型可以描述观察到的结果，但它们通常缺乏严谨性，无法在确定或调整参数的范围之外进行可靠的定量预测。然而，这些模型是有用的，使定性预测的影响，改变操作参数。此外，无论模型如何，它们表明CV随涂覆时间的平方根倒数而变化。更严格的DEM和CFD模型也被考虑。到目前为止，大多数工作都没有明确地集中在评估涂层质量均匀性上。然而，最近的研究表明，CV可以评估实验室规模的设备和非球形颗粒的影响，容器内部构件，以及由于应用涂层喷涂形成的液体桥都可以建模。
A review of different approaches to modeling the coating mass uniformity in fluidized bed and rotating drum (pans) equipment is presented. In order to predict the coefficient of variation (CV) of the coating mass distribution, the models must include the physics of non-uniform particle movement and/or non-uniform spray flux. Descriptive models for the coating process include those based on renewal theory, compartment models with appropriate population balances, and Monte Carlo simulation. These three approaches give reasonable fits to experimental data. However, they require certain model parameters to be adjusted to obtain a good fit with experimental results or, alternatively, parameters must be evaluated using an extensive experimental program. While such models can describe observed results, they generally lack the rigor to make reliable quantitative predictions outside the range for which the parameters were determined or adjusted. Nevertheless, these models are useful for making qualitative predictions about the effects of changing operating parameters. In addition, regardless of the model, they show that the CV changes with the inverse square root of coating time. More rigorous DEM and CFD models are also considered. Most work to date has not focused explicitly on evaluating the coating mass uniformity. However, recent studies show that CV can be evaluated for laboratory scale equipment and that the effects of non-spherical particles, vessel internals, and the formation of liquid bridges due to the application of coating spray can all be modeled.