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 pharmaceutical composition comprising said salt or cocrystal, and a method of treating pain in a subject in need thereof by administering an effective amount of said salt or cocrystal.