The invention relates to a pharmaceutical composition comprising an interleukin-13 antibody, more particularly a monoclonal interleukin-13 antibody, especially a human interleukin-13 monoclonal antibody, to a process for purifying said antibody and to the use of said composition in treating interleukin-13 related disorders, such as asthma, atopic dermatitis, allergic rhinitis, fibrosis, chronic obstructive pulmonary disease, scleroderma, inflammatory bowel disease and Hodgkin's lymphoma, particularly asthma.