US4877561A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing liposome
Assignee: Takeda Pharmaceutical Co Ltd
•
Filing: 1987-04-02
•
Granted: 1989-10-31
•
Expires: 2007-04-02
Abstract
Abstract Liposomes with an increased drug trap can be prepared by adding a readily volatile organic solvent to a drug-containing liquid with liposomes dispersed therein to cause gel formation and then removing said organic solvent by evaporation.
Inventors
- 👤 Katsumi Iga
- 👤 Naoru Hamaguchi
- 👤 Yasuaki Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:01
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/10; A61K9/127; A61K9/1277; Y; Y10; Y10S; Y10S436/00; Y10S436/829; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
58 words
A method of producing liposomes with increased drug trap ratio, which comprises (1) providing a dispersion containing a drug and liposomes prepared from a phospholipid, (2) adding an organic solvent having a boiling point not higher than 100° C. to the dispersion to cause gel formation, and then (3) removing said organic solvent by evaporation to reconstitute liposomes.
Claim 2
Independent Claim
58 words
A method of producing liposomes with increased drug trap ratio, which comprises (1) providing a dispersion containing a drug and liposomes prepared from a phospholipid, (2) adding an organic solvent having a boiling point not higher than 100° C. to the dispersion to cause gel formation, and then (3) removing said organic solvent by evaporation to reconstitute liposomes.
Claim 3
Dependent Claim
13 words
The method according to claim 1, wherein the dispersion contains multilamellar vesicles (MLV).
Claim 4
Dependent Claim
14 words
The method according to claim 1, wherein the dispersion contains small unilamellar vesicles (SUV).
Claim 5
Dependent Claim
25 words
The method according to claim 1, wherein the drug is a hydrophilic drug having an octyl alcohol/water-distribution ratio lower than 10 as the logarithmic value.
Claim 6
Dependent Claim
31 words
The method according to claim 1, wherein the drug is selected from the group consisting of antiinflammatory analgesics, lymphokines, anticancer agents, immunopotentiators, phsyiologically active peptides, antibiotics, antiprotozoa agents, enzymes and antiallergics.
Claim 7
Dependent Claim
12 words
The method according to claim 5, wherein the lymphokine is interleukin 2.
Claim 8
Dependent Claim
12 words
The method according to claim 5, wherein the anticancer agent is cisplatin.
Claim 9
Dependent Claim
17 words
The method according to claim 5, wherein the antiinflammatory analgesic is manganese superoxide dismutase or superoxide dismutase-PEG.
Claim 10
Dependent Claim
13 words
The method according to claim 1, wherein the organic solvent is ethyl ether.
Claim 11
Dependent Claim
12 words
The method according to claim 1, wherein the organic solvent is acetone.
Claim 12
Dependent Claim
13 words
The method according to claim 1, wherein the organic solvent is ethyl alcohol.
Claim 13
Dependent Claim
35 words
The method according to claim 1, wherein the organic solvent is added in amount of about 1 to 30 parts by volume per 10 parts by volume of the dispersion containing a drug and liposomeses.
Claim 14
Dependent Claim
28 words
The method according to claim 12, wherein the amount of the organic solvent is 2 to 10 parts by volume on the same basis described in claim 12.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |