Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

A systematic measurement of the solubility of cytarabine in water, methanol, ethanol, and ethanediol at atmospheric pressure has been carried out at temperature ranging from (293.15 to 333.15) K by a gravimetric method. The melting temperature (Tm) and molar fusion enthalpy of cybarabine were measured using DSC. The results showed that the dissolution of cytarabine in all examined solvents is endothermic process. Subsequently, the experimental data were well correlated using modified Apelblat equation, lambda-h equation, Wilson model, and NRTL model, respectively. Further, combining the measured solubility data and calculated ideal solubility data, activity coefficients of cytarabine in different solvents were estimated by neglecting the validity of heat capacity, which were then fitted to a van't Hoff like equation to estimate the mixing enthalpy and mixing entropy respectively. Moreover, polymorphic behavior of cybarabine has been observed, which was validated using DSC and PXRD analysis.