Patent ID: 7439235

Claim:
A method for obtaining a natural mixture, depleted in phenolic urine contents, of conjugated estrogens from pregnant mares' urine, comprising: a) contacting a pregnant mare urine with an amount of a polymeric adsorption resin sufficient to absorb the mixture of conjugated estrogens contained in the urine, and separating a polymeric adsorption resin laden with the mixture of conjugated estrogens from the rest of the urine, b) washing the polymeric adsorption resin laden with the mixture of conjugated estrogens with an alkaline washing water which has a pH of at least 12.0, and c) contacting the washed adsorption resin with a sufficient amount of an elution liquid to desorb the mixture of conjugated estrogens adsorbed on the resin, said elution liquid comprising a water-miscible organic solvent selected from the group consisting of water-miscible ethers, lower alkanols and lower aliphatic ketones or a mixture of the water-miscible organic solvent and water which has optionally been rendered alkaline, and separating an eluate containing the natural mixture of conjugated estrogens from the adsorption resin, and optionally concentrating the separated eluate, wherein the polymeric adsorption resin laden with the mixture of conjugated estrogens is washed with water in an intermediate washing between process steps b) and c).