14-O - {[(1R, 2R, 4R) -4-amino-2-hydroxy-cyclohexylsulfanyl] -acetyl} -butyl of formula ** (See formula) ** in the form of an acetate in crystalline form B, characterized by a powder X-ray diffraction pattern with 2-theta peaks (degrees, ± 0.2) at 10.3, 10.7, 12.7, 14.3, 15.5, 16.0, 17, 2, 19.5, 20.6, 22.9.14-O-{[(1R,2R,4R)-4-amino-2-hidroxi-ciclohexilsulfanil]-acetil}-mutilina de fórmula **(Ver fórmula)** en forma de un acetato en forma cristalina B, caracterizado por un patrón de difracción de rayos X en polvo con picos 2-theta (grados, ± 0,2) en 10,3, 10,7, 12,7, 14,3, 15,5, 16,0, 17,2, 19,5, 20,6, 22,9.