Van Bockstal Pieter-Jan, De Meyer Laurens, Corver Jos, Vervaet Chris, De Beer Thomas
Laboratory of Pharmaceutical Process Analytical Technology, Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent 9000, Belgium.
Laboratory of Pharmaceutical Technology, Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Ghent University, Ghent 9000, Belgium.
J Pharm Sci. 2017 Jan;106(1):71-82. doi: 10.1016/j.xphs.2016.05.003. Epub 2016 Jun 16.
Recently, an innovative continuous freeze-drying concept for unit doses was proposed, based on spinning the vials during freezing. An efficient heat transfer during drying is essential to continuously process these spin frozen vials. Therefore, the applicability of noncontact infrared (IR) radiation was examined. The impact of several process and formulation variables on the mass of sublimed ice after 15 min of primary drying (i.e., sublimation rate) and the total drying time was examined. Two experimental designs were performed in which electrical power to the IR heaters, distance between the IR heaters and the spin frozen vial, chamber pressure, product layer thickness, and 5 model formulations were included as factors. A near-infrared spectroscopy method was developed to determine the end point of primary and secondary drying. The sublimation rate was mainly influenced by the electrical power to the IR heaters and the distance between the IR heaters and the vial. The layer thickness had the largest effect on total drying time. The chamber pressure and the 5 model formulations had no significant impact on sublimation rate and total drying time, respectively. This study shows that IR radiation is suitable to provide the energy during the continuous processing of spin frozen vials.
最近，基于在冷冻过程中旋转小瓶，提出了一种用于单位剂量的创新型连续冷冻干燥概念。干燥过程中的高效传热对于连续处理这些旋转冷冻的小瓶至关重要。因此，研究了非接触式红外（IR）辐射的适用性。考察了几个工艺和配方变量对一次干燥15分钟后升华冰的质量（即升华速率）和总干燥时间的影响。进行了两个实验设计，其中包括红外加热器的电功率、红外加热器与旋转冷冻小瓶之间的距离、腔室压力、产品层厚度以及5种模型配方作为因素。开发了一种近红外光谱法来确定一次干燥和二次干燥的终点。升华速率主要受红外加热器的电功率以及红外加热器与小瓶之间距离的影响。层厚度对总干燥时间影响最大。腔室压力和5种模型配方分别对升华速率和总干燥时间没有显著影响。这项研究表明，红外辐射适用于在连续处理旋转冷冻小瓶的过程中提供能量。
