Apixaban-nicotinic acid monohydrate co-crystal, which was composed of a mol. apixaban, a mol. nicotinic acid and a mol. water.Apixaban and nicotinic acid were resp. dissolved in trifluoroethanol containing 0.5% water at 25 °C and stirred 3 h.And then added Et acetate and stirred 2 h at same temperature to precipitate the co-crystal.The co-crystal was obtained through filtering and drying.The structure of co-crystal was characterized by ∼1H-NMR, elements anal., water content anal., X-ray power diffraction(XRPD), differential scanning calorimetry(DSC), thermal gravimetric anal.(TGA) and IR(IR) spectrum, resp.The stability, solubility and hygroscopicity of the co-crystal were also assessed.The results showed that the solubility of co-crystal in various pH solution were increased to two to three times as compared with apixaban.The phys. and chem. properties of co-crystal are very good.♂