Abstract
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°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.
| Original language | English |
|---|---|
| Pages (from-to) | 748-760 |
| Number of pages | 13 |
| Journal | Journal of Pharmaceutical Sciences |
| Volume | 95 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 2006 |
| Externally published | Yes |
Keywords
- 4-Hydroxybenzoic acid
- Complexation
- Desolvation
- p-hydroxybenzoic acid
- Polymorphism
- Pseudopolymorphism
- Solid state stability
- Solubility
- Solvate
- Van't Hoff