Oesterle J, Franks F, Auffret T
Biopreservation Division, Pafra Ltd., Cambridge, United Kingdom.
Pharm Dev Technol. 1998 May;3(2):175-83. doi: 10.3109/10837459809028493.
The purpose of this work was to investigate the phase behavior of tertiary butanol (TBA) and volatile ammonium salts in frozen mixtures with some commonly used excipients and the efficacy of such volatile additives in accelerating the sublimation of ice from frozen solutions. Differential scanning calorimetry was employed to determine first-order phase transformations and glass transition temperatures in binary and ternary mixtures. Ice sublimation rates were studied by conventional freeze-drying and mass loss with time. A eutectic temperature (268 K) was identified for the anhydrous TBA-sucrose system. In frozen ternary water-excipient-TBA systems, the relative amplitudes of the glass and phase transitions, as measured during warming scans, were found to depend critically on the previous cooling rates. Glass transitions of all the freeze-concentrated mixtures used were determined. The sublimation studies indicated an ability of all volatile additives to accelerate ice sublimation from amorphous, freeze-concentrated solutions, but no clear ranking order, applicable to all systems studied, could be established.
本研究旨在探究叔丁醇（TBA）与挥发性铵盐在含有一些常用辅料的冷冻混合物中的相行为，以及此类挥发性添加剂在加速冷冻溶液中冰升华方面的效果。采用差示扫描量热法测定二元和三元混合物中的一级相变和玻璃化转变温度。通过常规冷冻干燥和随时间的质量损失来研究冰升华速率。确定了无水TBA - 蔗糖体系的共晶温度（268 K）。在冷冻的三元水 - 辅料 - TBA体系中，升温扫描过程中测得的玻璃化转变和相变的相对幅度被发现严重依赖于先前的冷却速率。测定了所有使用的冷冻浓缩混合物的玻璃化转变。升华研究表明，所有挥发性添加剂都有能力加速无定形冷冻浓缩溶液中的冰升华，但无法建立适用于所有研究体系的明确排序。
