(2R,3R,4R,5S)-2,3,4,5,6-Pentahydroxyhexyl 2-(4-isobutylphenyl) propanoate compound with (2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl 2-(4-isobutylphenyl) propanoate (1:1),(2R,3R,4R,5S)-2,3,4,5,6-Pentahydroxyhexyl 2-(4-isobutylphenyl) propanoate compound with (2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl 2-(4-isobutylphenyl) propanoate (1:1),Ibuprofen Impurity