An Investigation of the Relationship between Glass Transition Temperatures and the Crystallinity of Spray-Dried Powders
An Investigation of the Relationship between Glass Transition Temperatures and the Crystallinity of Spray-Dried Powders
复制标题
喷雾干燥粉末玻璃化转变温度与结晶度关系的研究
DOI：
10.1080/07373931003641586
复制
发表时间：
2010
影响因子：
3.3
通讯作者：
T. Langrish
中科院分区：
文献类型：
--
作者：
M. I. Islam;R. Sherrell;T. Langrish
研究了乳糖、蔗糖和抗坏血酸溶液在Buchi B-290喷雾干燥机中的玻璃化转变温度与喷雾干燥粉末结晶度之间的关系。采用吸水率测试和调制差示扫描量热仪(MDSC)对其结晶度进行了表征。玻璃化转变温度最低的抗坏血酸在几乎所有的喷雾干燥条件下几乎都是完全结晶的，而玻璃化转变温度最高的乳糖在不同的喷雾干燥条件下都是部分无定形和部分结晶的。对于乳糖，将入口空气温度从134°C改变到210°C会使结晶度变化约10%。对于蔗糖，类似的温度变化会更大程度地改变结晶度，从高温下几乎完全结晶到较低温度下非常无定形。这些结果与Williams-Landel-Ferry方程和材料温度与玻璃化转变温度之差越大的结晶速率理论是一致的。对蔗糖和抗坏血酸的测定表明，这些物质在干燥室中的降解量不到10%。
The relationship between the glass transition temperature and the crystallinity of spray-dried powders has been investigated in this study, by spray drying solutions of lactose, sucrose, and ascorbic acid in a Buchi B-290 spray dryer (Buchi, Switzerland). The degree of crystallinity was assessed using water sorption tests and modulated differential scanning calorimetry (MDSC). The material with the lowest glass transition temperature, ascorbic acid, is almost completely crystalline under virtually all spray-drying conditions, whereas the material with the highest glass transition temperature, lactose, is partly amorphous and partly crystalline under different spray-drying conditions. With lactose, changing the inlet air temperature from 134 to 210°C changes the degree of crystallinity by about 10%. For sucrose, a similar change in temperature changes the degree of crystallinity by a larger amount, from almost completely crystalline at high temperatures to very amorphous at lower temperatures. These results are consistent with the Williams-Landel-Ferry equation and with the theory that the rate of crystallization is greater when the difference between the material temperature and the glass transition temperature of the material is higher. Tests on sucrose and ascorbic acid using liquid chromatography and chemical assays have shown that the amount of degradation for these materials in the drying chamber is less than 10%.