A crystal of 4,4 '- [4-fluoro-7 - ({4- [4- (3-fluoro-2-methylphenyl) butoxy] phenyl} ethynyl) -2-methyl-1H-indole-1,3 acid - diyl] dibutanoic having at least peaks of approximately 7.29, 10.24, 12.15, 17.95 and 18.44 in 2θ degrees in an X-ray powder diffraction spectrum.Un cristal del acido 4,4'-[4-fluoro-7-({4-[4-(3-fluoro-2-metilfenil)butoxi]fenil}etinil)-2-metil-1H-indol-1,3- diil]dibutanoico que tiene al menos picos de aproximadamente 7,29, 10,24, 12,15, 17,95 y 18,44 en grados 2θ en un espectro de difracción en polvo de rayos X.