摘要
为解决中药浸膏喷雾干燥时易出现粘连和软化的问题,提出将除湿空气运用于中药浸膏喷雾干燥,并用玻璃化转变理论和水分活度理论预测浸膏粉储存稳定性的条件。以口炎清浸膏为模型药,分别对湿空气(RH 70%)和干空气条件进行喷雾干燥,同时考察干空气下不同压缩空气比对喷雾结果的影响及进风温度分别为100,110,120,130,140℃时对喷雾干燥粉粉体学性质(浸膏得粉率、粘连百分比、含水量、休止角、压缩度、粒径大小与分布)的影响。对理想粉末进行吸湿性和不同平衡含水量下玻璃化转变温度(Tg)的测定,分别用GAB方程和Gordon-Taylor模型对水分活度与平衡含水量之间以及平衡含水量与Tg之间进行拟合,得到口炎清浸膏粉的状态图,指导其合理储存条件。研究发现,干空气下浸膏粉含水量随着压缩空气比的增加而降低且压缩空气比为100%时喷雾效果最好。湿空气下浸膏粉的得率极低,其含水量和Tg分别为4.26%,16.73℃;其他相同仪器参数相同,干空气下浸膏粉的含水量和Tg分别为2.43%,24.86℃,与湿空气相比,含水量降低了42.96%,Tg提高了8.13℃。从状态图分析可知口炎清浸膏粉在25℃下达稳态时的临界含水量(X,c)为3.42%,临界水分活度(aw,c)为0.188。由此可见,水分降低了中药浸膏粉的Tg是造成其喷雾干燥粘壁和软化的主要原因,因此加入干空气对于中药浸膏喷雾干燥有重要的指导作用。
In order to solve the adhesion and the softening problems of traditional Chinese medicine extract during spray drying, a new method of adding dehumidified air into spray drying process was proposed, and the storage stability conditions of extract powder could be predicted. Kouyanqing extract was taken as model drug to investigate on the wet air （ RH = 70% ） and dry air conditions of spray drying. Under the dry air condition, the influence of the spray drying result with different air compression ratio and the spray- dried powder properties （ extract powder recovery rate, adhesion percentage, water content, angle of repose, compression ratio, particle size and distribution） with 100,11O, 120,130,140 ℃ inlet temperature were studied. The hygroscopic investigation and Tg value with different moisture content of ideal powder were determined. The water activity-equilibrium moisture content （aw-EMC） and the equilibrium moisture content-Ts （EMC-Ts~ relationships were fitted by GAB equation and Gordon-Taylor model respectively, and the state diagram of kouyanqing powder was obtained to guide the rational storage conditions. The study found that in the condition of dry air, the extract powder water content decreased with the increase of air compression ratio and the spray drying effect with air compres- sion ratio of 100% was the best performance; in the condition of wet air, the extract powder with high water content and low yield, and the value were 4. 26% and 16. 73 ℃, while, in the dry air condition the values were 2.43% and 24. 86 ℃ with the same other instru- ment parameters. From the analysis of kouyanqing powder state diagram, in order to keep the stability , the critical water content of 3.42% and the critical water content of 0. 188. As the water decreased Tg value of extract powder is the major problem of causing adhe- sion and softening during spray drying, it is meaningful to aid dehumidified air during the process.
出处
《中国中药杂志》
CAS
CSCD
北大核心
2015年第3期424-429,共6页
China Journal of Chinese Materia Medica
基金
国家自然科学基金项目(81260644)
"赣鄱555"工程领军人才培养计划项目
关键词
干空气
喷雾干燥
玻璃化转变温度
状态图
dry air
spray drying
temperature of glass transition
state diagram
