Patent ID: 7964586

Claim:
A method for obtaining a natural mixture of conjugated estrogens from pregnant mares' urine, comprising: contacting a urine with an amount of a polymeric adsorption resin sufficient to adsorb the mixture of conjugated estrogens contained in the urine, and separating a resulting polymeric adsorption resin loaded with the mixture of conjugated estrogens from the rest of the urine; washing the polymeric adsorption resin loaded with the mixture of conjugated estrogens with a washing water which has been adjusted to a pH value of at least 12.0; contacting the washed adsorption resin with a sufficient amount of an elution liquid to desorb the mixture of conjugated estrogens loaded thereon, wherein the elution liquid is a one-phase or two phase mixture containing: (i) water, (ii) at least one water-immiscible or only slightly water-miscible organic solvent suitable for the elution of the non-conjugated lipophilic compounds selected from the group consisting of non-conjugated flavonoids, non-conjugated isoflavonoids, non-conjugated norisoprenoids, and non-conjugated steroids, and which organic solvent is selected from the group consisting of straight-chain, branched or cyclic C 4 -C 10 alcohols, C 1 -C 10 esterified acids, C 3 -C 10 aldehydes, C 4 -C 10 ketones, C 3 -C 10 ethers, C 3 -C 6 nitriles, C 1 -C 3 haloalkanes, and mixtures of two or more of the foregoing solvents; and (iii) at least one water-miscible organic solvent selected from the group consisting of water-miscible ethers, lower alkanols, lower aliphatic ketones, and mixtures of two or more of the foregoing solvents; separating an eluate containing the natural mixture of conjugated estrogens from the adsorption resin; wherein the natural mixture of conjugated equine estrogens obtained is depleted in phenolic urine contents and in non-conjugated lipophilic compounds selected from the group consisting of non-conjugated flavonoids, non-conjugated isoflavonoids, non-conjugated norisoprenoids, and non-conjugated steroids; and if the separated eluate is a two-phase mixture, further comprising separating the phases and recovering an aqueous phase containing the natural mixture of conjugated estrogens.