Measurement and correlation of the solubility of rivaroxaban (form I) in binary mixtures of ethyl acetate with tetrahydrofuran, N,N-dimethylformamide, and N,N-dimethylacetamide from T = (278.15 to 318.15) K

• The solubility of rivaroxaban (form I) in binary mixtures of EA with THF, DMF and DMA was reported.
• The solubility of rivaroxaban (form I) decreased in the order of DMA > DMF > THF > EA.
• The Jouyban–Acree (JA) equation and Buchowski (λh) equation were verified to correlate the experimental data.

In this work, the solubility of rivaroxaban (form I) in binary solvent mixtures of ethyl acetate (EA) with N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA) and tetrahydrofuran (THF) was firstly experimentally measured over the temperature range from (278.15 to 318.15) K. Then the measured solubility data were correlated with such semiempirical thermodynamic models as Jouyban–Acree (JA) equation and Buchowski (λh) equation. The crystal form of the residual solids in equilibrium with liquids was identified by powder X-ray diffraction (PXRD). The melting temperature and fusion enthalpy were determined using differential scanning calorimetry (DSC). The results show that, the solubility of rivaroxaban generally increases with the temperature and decreases with the increase in the content of EA in the binary solvent mixtures. Furthermore, when λh equation is used to correlate the solubility of rivaroxaban with the temperature in each solvent mixture, the average relative deviation (ARD) between the experimental and calculated values is about 0.0671, while it is about 0.0905 when JA equation is employed to correlate the solubility with the temperature and the composition of solvent mixtures simultaneously.

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