Method for obtaining estrogens from mare's urine
View Patent ↗A method for obtaining an extract from a natural mixture of conjugated estrogens from the urine of pregnant mares (PMU) by solid-phase extraction on semipolar adsorption resins in which the resulting extract meets the pharmaceutical specifications for conjugated estrogens and the content of free estrogens is minimized even if old pregnant mares' urine and/or pregnant mares' urine which has been stored or transported at elevated temperatures is used.
1. 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).
2. A method according to claim 1 , wherein the urine in step a) is a urine freed of mucilaginous substances and solids, a reduced concentrate of such urine or a reduced urine retentate obtained by membrane filtration of such urine.
3. A method according to claim 1 , wherein said intermediate washing is carried out at temperatures below room temperature.
4. A method according to claim 3 , wherein said intermediate washing is carried out at a temperature between 0° C. and 10° C.
5. A method according to claim 4 , wherein said intermediate washing is carried out at a close to but above 0° C.
6. A method according to claim 1 , wherein the washing water used for the intermediate washing operation is precooled to temperatures below room temperature.
7. A method according to claim 6 , wherein the washing water used for the intermediate washing is precooled to a temperature between 0° C. and 10° C.
8. A method according to claim 7 , wherein the washing water used for the intermediate washing is precooled to a temperature close to but above 0° C.
9. A method according to claim 1 , wherein the alkaline washing water used in step b) is precooled to a temperature below room temperature.
10. A method according to claim 9 , wherein the alkaline washing water used in step b) is precooled to a temperature between 0° C. and 10° C.
11. A method according to claim 10 , wherein the alkaline washing water used in step b) is precooled to a temperature close to but above 0° C.
12. A method according to claim 1 , wherein step b) and the intermediate washing are both carried out at temperatures below room temperature.
13. A method according to claim 12 , wherein step b) and the intermediate washing are both carried out at temperatures between 0° C. and 10° C.
14. A method according to claim 13 , wherein step b) and the intermediate washing are both carried out at temperatures close to but above 0° C.
15. A method according to claim 1 , wherein the polymeric adsorption resin is contained in a reactor, and the reactor containing the adsorption resin is precooled to a temperature below room temperature.
16. A method according to claim 15 , wherein the reactor containing the adsorption resin is precooled to a temperature between 0° C. and 10° C.
17. A method according to claim 16 , wherein the reactor containing the adsorption resin is pre-cooled to a temperature close to but above 0° C.
18. A method according to claim 16 , wherein the pregnant mare urine is pre-cooled to a temperature below room temperature.
19. A method according to claim 18 , wherein the pregnant mare urine is pre-cooled to a temperature between 0° C. and 10° C.
20. A method according to claim 19 , wherein the pregnant mare urine is pre-cooled to a temperature close to but above 0° C.
21. A method according to claim 1 , wherein the adsorption resin is a semipolar adsorption resin.
22. A method according to claim 21 , wherein the adsorption resin is a non-ionic semipolar adsorption resin.