US4377526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of purifying eicosapentaenoic acid and its esters
Assignee: Nissui Corp
•
Filing: 1981-12-11
•
Granted: 1983-03-22
•
Expires: 2001-12-11
Abstract
Abstract A method of purifying eicosapentaenoic acid and esters of eicosapentaenoic acid comprising subjecting a mixture containing eicosapentaenoic acid or an ester of eicosapentaenoic acid to the following steps in either order: (1) urea treatment, where the treatment comprises contacting the mixture with a polar organic solvent containing dissolved urea whereby a solution containing the acid or ester is formed, precipitating urea crystals from the solution, and removing the urea crystals, and (2) fractional distillation.
Inventors
- 👤 Takao Fujita
- 👤 Masahiro Makuta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:27
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/43; C07C51/44; C07C67/00; C07C67/48; C07C67/52; C07C67/54; C07C67/60
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
71 words
A method of purifying eicosapentaenoic acid and esters of eicosapentaenoic acid, comprising: treating a mixture containing eicosapentaenoic acid or an ester of eicosapentaenoic acid with urea, wherein said treating comprises contacting said mixture with a polar organic solvent and urea so that a solution containing said acid or ester and urea is formed, precipitating urea crystals from said solution, and removing said crystals from said solution; and fractionally distilling said mixture.
Claim 2
Independent Claim
71 words
A method of purifying eicosapentaenoic acid and esters of eicosapentaenoic acid, comprising: treating a mixture containing eicosapentaenoic acid or an ester of eicosapentaenoic acid with urea, wherein said treating comprises contacting said mixture with a polar organic solvent and urea so that a solution containing said acid or ester and urea is formed, precipitating urea crystals from said solution, and removing said crystals from said solution; and fractionally distilling said mixture.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein said distilling comprises heating at no more than 250° C. for no more than 4 hours.
Claim 4
Dependent Claim
12 words
The method of claim 1, wherein said solvent is ethanol or methanol.
Claim 5
Dependent Claim
21 words
The method of claim 1, wherein urea is present in said solution at a concentration of 10 to 20% by weight.
Claim 6
Dependent Claim
20 words
The method of claim 1, wherein the weight ratio of urea to said acid or ester is at least 0.5.
Claim 7
Dependent Claim
13 words
The method of claim 5, wherein said ratio ranges from 1 to 2.
Claim 8
Dependent Claim
14 words
The method of claim 1, wherein said mixture is a natural fat or oil.
Claim 9
Dependent Claim
20 words
The method of claim 1, wherein said mixture is obtained by saponification or alcoholysis of a natural fat or oil.
Claim 10
Dependent Claim
19 words
The method of claim 7 or 8, wherein said natural fat or oil is obtained from a marine organism.
Claim 11
Dependent Claim
24 words
The method of claim 1, wherein said ester is a lower alkyl ester having 1 to 5 carbon atoms in the alkyl portion thereof.
Claim 12
Dependent Claim
12 words
The method of claim 10 wherein said ester is an ethyl ester.
Claim 13
Dependent Claim
13 words
The method of claim 1, wherein said urea treating preceeds said fractionally distilling.
Claim 14
Dependent Claim
41 words
The method of claim 1, wherein said fractionally distilling comprises continuous distilling wherein a main distillate fraction containing at least 40% by weight of said acid or said ester is obtained, and wherein said fractionally distilling preceeds said treating with urea.
Claim 15
Dependent Claim
18 words
The method of claim 13, wherein said main distillate fraction is obtained within no more than two hours.
References Cited (Backward Citations)
US2573897A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-21 | 1986-09-20 | 1987-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-21 | 1990-09-20 | 1991-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-21 | 1994-09-20 | 1995-03-22 | $7700.00 | Window Closed / Lapsed |