A dry composition for use in therapy or diagnosis, obtainable by drying an aqueous composition comprising a protein and one or more displacement buffers, wherein the pH of the aqueous composition is such that the protein is stable, wherein the or each displacement buffer has a pKa that is at least 1 unit greater or less than the pH of the aqueous composition, and wherein the aqueous composition is substantially free of a conventional buffer having a pKa that is within one pH unit of the pH of the aqueous composition.
