The invention provides a method for preparing a biologically active complex,said method comprising dissolving amixture of a polypeptide element, such as alphalactalbumin or fragmentsthereof, in powder form and oleic acid or a pharmaceuticallyacceptable salt thereof also in solid form, in an aqueous solvent comprising amixture of at least two and preferably three salts, whereinthe method is carried out at moderate temperatures. The preparation does notrequire extensive heating and so is simple and efficientto cam/ out.
