The invention comprises a complex of a ferric salt of fluorescein and a mono-ricinoleyl ether of a polyethylene glycol of molecular weight above 1500, the ether having been peroxidized with a gas containing molecular oxygen at an elevated temperature in the presence of copper as catalyst.  The complex is said to have a selective peroxidasic activity towards polyphenols and to have emulsifying and solvent properties.  It may be used in cosmetic or medicated creams and lotions.  In an example, the mono-ricinoleyl ether of a polyethylene glycol M.W. 6000 is peroxidized by heating in air at 170 DEG  C. in the presence of copper chippings and is then mixed with an aqueous solution of ferric chloride followed by an aqueous solution of soluble fluorescein; to the resulting complex is added a further quantity of the peroxidized ricinoleyl ether.ALSO:The invention comprises a substance having peroxidasic activity comprising a complex of (a) a colloidal active component consisting of a mono ether from a polyethylene glycol of a molecular weight above 1500 and ricinoleyl alcohol, the mono-ricinoleyl-ether having been peroxidized with a gas containing molecular oxygen at an elevated temperature in the presence of copper as a catalyst and (b) an activating component consisting of an oxidizing substance which does not affect the molecular structure of the mono-ether, for example the ferric salt of fluorescein or hydrogen peroxide.  In the formation of the complex, the oxidizing substance in liquid state, or an aqueous solution of such substance if normally solid, is intimately mixed with the peroxidized monoether and the mixture diluted with water if necessary; the mixing is carried out at atmospheric temperature.  The peroxidation of the mono-ricinoleyl ether of the glycol is preferably effected at 100-170 DEG  C. with the copper in the form of chippings. In an example, the mono-ricinoleyl ether of a polyethylene glycol of M.W. about 6000 is heated for 10-60 mins. in air in the presence of copper chippings at 170 DEG  C.  The peroxidized ether so obtained is mixed with an aqueous solution of ferric chloride and then an aqueous solution of soluble fluorescein is added; finally, to the resulting complex a quantity of the peroxidized ricinoleyl ether is added.  The complexes are stated to have a selective peroxidasic activity towards certain polyphenols, and also to have emulsifying and solvent properties. They may be used in cosmetic and/or medicated lotions and creams.ALSO:Cosmetic and/or medicated creams and lotions and the like comprise an ingredient showing peroxidasic activity comprising a complex of (a) a mono ricinoleyl ether of a polyethylene glycol having a molecular weight above 1500, the ether having been peroxidized with a gas containing molecular oxygen at an elevated temperature in the presence of copper as a catalyst; and (b) an oxidizing substance which does not affect the molecular structure of the mono-ether, such as the ferric salt of fluorescein or hydrogen peroxide (see also Group IV (a)).  An example describes a preparation of the ferric fluoresceinate complex comprising heating a monoricinoleyl ether of a polyethylene glycol of M.W. 6000 in air at 170 DEG  C. in the presence of copper and adding thereto an aqueous solution of ferric chloride and then an aqueous solution of soluble fluorescein; the product is then diluted with more of the peroxidized ether.