Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, 69 N. Eagleville Rd., Storrs, Connecticut 06269, USA.
J Pharm Sci. 2010 Jul;99(7):3188-204. doi: 10.1002/jps.22086.
This study is aimed at characterizing and understanding different modes of heat and mass transfer in glass syringes to develop a robust freeze-drying process. Two different holder systems were used to freeze-dry in syringes: an aluminum (Al) block and a plexiglass holder. The syringe heat transfer coefficient was characterized by a sublimation test using pure water. Mannitol and sucrose (5% w/v) were also freeze-dried, as model systems, in both the assemblies. Dry layer resistance was determined from manometric temperature measurement (MTM) and product temperature was measured using thermocouples, and was also determined from MTM. Further, freeze-drying process was also designed using Smart freeze-dryer to assess its application for freeze-drying in novel container systems. Heat and mass transfer in syringes were compared against the traditional container system (i.e., glass tubing vial). In the Al block, the heat transfer was via three modes: contact conduction, gas conduction, and radiation with gas conduction being the dominant mode of heat transfer. In the plexiglass holder, the heat transfer was mostly via radiation; convection was not involved. Also, MTM/Smart freeze-drying did work reasonably well for freeze-drying in syringes. When compared to tubing vials, product temperature decreases and hence drying time increases in syringes.
本研究旨在描述和理解玻璃注射器中不同的热质传递模式，以开发稳健的冷冻干燥工艺。使用两种不同的支架系统在注射器中进行冷冻干燥：铝块和有机玻璃支架。通过使用纯水的升华测试来表征注射器的传热系数。甘露醇和蔗糖（5%w/v）也在两种组件中作为模型体系进行冷冻干燥。通过压力计温度测量（MTM）确定干燥层阻力，并使用热电偶测量产品温度，也可以通过 MTM 确定。此外，还使用 Smart freeze-dryer 设计了冷冻干燥过程，以评估其在新型容器系统中的冷冻干燥应用。将注射器中的热质传递与传统容器系统（即玻璃管瓶）进行了比较。在铝块中，传热通过三种方式进行：接触传导、气体传导和辐射，其中气体传导是传热的主要方式。在有机玻璃支架中，传热主要通过辐射进行；不涉及对流。此外，MTM/Smart freeze-dryer 对于注射器中的冷冻干燥效果相当好。与管瓶相比，产品温度下降，因此注射器中的干燥时间增加。
