Nordström Fredrik L, Rasmuson Ake C
Department of Chemical Engineering and Technology, Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
J Pharm Sci. 2006 Apr;95(4):748-60. doi: 10.1002/jps.20569.
The prevalence of phases and associated solubilities of p-hydroxybenzoic acid have been investigated in methanol, acetonitrile, acetic acid, acetone, water, and ethyl acetate at temperatures from 10 to 50 degrees C. Thermodynamic data was acquired through determination of van't Hoff enthalpy of solution, enthalpy of fusion, and melting temperature. Indications of polymorphic enantiotropy were found primarily through solubility analysis and FTIR-ATR. A comprehensive thermodynamic investigation disclosed correlation between the van't Hoff enthalpy of solution and the solubility in different solvents. A higher solubility is linked to a lower van't Hoff enthalpy of solution. A thermodynamic analysis to discriminate between different solid phases is presented.
在10至50摄氏度的温度范围内，研究了对羟基苯甲酸在甲醇、乙腈、乙酸、丙酮、水和乙酸乙酯中的物相及其相关溶解度。通过测定范特霍夫溶解焓、熔化焓和熔化温度来获取热力学数据。主要通过溶解度分析和傅里叶变换红外衰减全反射光谱（FTIR-ATR）发现多晶型对映异构现象。全面的热力学研究揭示了范特霍夫溶解焓与在不同溶剂中溶解度之间的相关性。较高的溶解度与较低的范特霍夫溶解焓相关联。本文提出了一种用于区分不同固相的热力学分析方法。
