The invention relates to a salt or cocrystal of 3-(3-dimethylamino-1-ethyl-2-methyl-propyl)- phenol (component a) and at least one acid component (b1 ) or at least one acid component (b2), wherein the salt or cocrystal of component (a) and component (b2) is present in crystalline and/or amorphous form, a medicament comprising said salt or cocrystal as well as said salt or cocrystal for use in the treatment of pain.La invención se refiere a una sal o co-cristal de 3-(3-dimetilamino-1-etil-2-metil-propil) -fenol (componente a) y al menos un componente ácido (b1) o al menos un componente ácido (b2), donde la sal o el co-cristal del componente (a) y el componente (b2) están presentes en forma cristalina y/o amorfa, a un medicamento que comprende a la sal o al co-cristal, así como a la sal o al co-cristal para su uso en el tratamiento del dolor.
