Crystal Structure, Characterization and Enhanced Solubility of Ibuprofen by 2-Methylimidazolium Salt

Novel crystalline forms of ibuprofen(IBU) with 2-methylimidazole(2 MI) in a 1:1 molar ratio was synthesized by liquid-assisted grinding technique and characterized by single-crystal X-ray diffraction, infrared spectral(IR), powder X-ray diffraction(PXRD),differential scanning calormetry(DSC) and Hirshfeld surface analysis. The structure of IBU-2 MI salt is assembled via N(1)–H(1)+···O1 and N(2)–H(2)+···O(2) hydrogen bonds to form the zigzag-like 1 D chain structure. The original purpose was to solve the pH-dependent solubility defect of ibuprofen, and the result of pH dependent solubility experiments showed that the IBU-2 MI salt had a better solubility at the wide range of pH 4.00 to 9.18. Furthermore, the solubility of IBU-2 MI salt exhibits a dramatic increase(30-fold) in aqueous mediums.