In this work, the thermodynamics of theophylline anhydrate and monohydrate were investigated. The solubilities of theophylline anhydrate and monohydrate in methanol water and isopropanol water mixtures were measured from 278.15 K to 303.15 K. Then the solubility data were correlated with the combined nearly ideal binary solvent/Redlich Kister (CNIBS/R K) model and the modified Jouyban Acree model, respectively. The water activity aT that corresponds to the transformation between hydrate and anhydrate forms of theophylline was investigated. The water activity was accurately calculated by the Wilson equation and correlated by the van t Hoff equation. The transformation enthalpy and entropy were calculated as well. The ternary phase diagrams of the theophylline methanol water system and theophylline isopropanol water system thus were obtained.
Compounds
#
Formula
Name
1
C7H8N4O2
3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione
2
CH4O
methanol
3
C3H8O
propan-2-ol
4
H2O
water
5
C7H10N4O3
theophylline monohydrate
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.