Disclosed is a method of manufacturing a COX- 2 inhibitor comprising: (a) mixing plasma with sodium bicarbonate (NaHC03) and incubating said mixture for sufficient time and at a temperature of no more than BO°C to produce a precipitate b) resolubilising said precipitate in the presence of an aqueous solution at a temperature of between about 8O°C and about 150°C, wherein either before, during or after the resolubilising step at least one metal, metal ion or metal salt thereof is admixed and (c) separating a COX- 2 inhibitor fraction from the resolubilised precipitate in step (b), which fraction comprises denatured plasma proteins and at least one metal, metal ion or metal salt thereof.
