Pena L E, Lee B L, Stearns J F
Drug Delivery R&D--Specialty Products, Upjohn Company, Kalamazoo, Michigan 49007.
Pharm Res. 1994 Jun;11(6):875-81. doi: 10.1023/a:1018990010686.
A model ointment consisting of white petrolatum, mineral oil and microcrystalline wax was studied using rheology, microscopy and thermal techniques. Rheograms studied over a temperature range of 25-40 degrees C indicated that the overall rheogram shape changed little as the temperature increased. However, two inflections gradually disappeared as the temperature increased. Thermal optical analysis showed that the temperature range over which these inflection disappeared correlated with the melting transition of the components forming the secondary structure. Another series of rheograms obtained from ointments with different combinations of the raw materials showed the rheology of the ointment is primarily controlled by the white petrolatum and mineral oil and that the microcrystalline wax acts to build-up the structure by incorporating itself into the existing white petrolatum structure. Thermal optical analysis of comelts of the raw materials proved that the ointment network structure is essentially a recombination of the naturally occurring components in differing ratios. The knowledge obtained from these studies is applied to a discussion of the thermal and mechanical stresses encountered in the filling operation.
使用流变学、显微镜技术和热分析技术对一种由白凡士林、矿物油和微晶蜡组成的模型软膏进行了研究。在25至40摄氏度温度范围内研究的流变图表明，随着温度升高，整体流变图形状变化不大。然而，随着温度升高，两个拐点逐渐消失。热光学分析表明，这些拐点消失的温度范围与形成二级结构的组分的熔融转变相关。从具有不同原料组合的软膏获得的另一系列流变图表明，软膏的流变学主要由白凡士林和矿物油控制，微晶蜡通过融入现有的白凡士林结构来构建结构。原料共熔物的热光学分析证明，软膏网络结构本质上是天然存在的组分以不同比例的重组。从这些研究中获得的知识被应用于讨论灌装操作中遇到的热应力和机械应力。
