US4394372A
Expired / Lapsed
US
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Process for making lipid membrane structures
Assignee: Procter and Gamble Co
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Filing: 1982-01-15
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Granted: 1983-07-19
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Expires: 2002-01-15
Abstract
Abstract A process for producing lipid membrane structures (vesicles or liposomes) is disclosed, wherein a solution of bilayer forming compounds in a narrowly-defined two component solvent system is dispersed in an aqueous solution and, subsequently, at least a portion of that solvent system is stripped off. This process permits the readily-reproducible production of lipid membrane structures under gentle processing conditions, ideal for use when they contain pharmaceutically-active materials.
Inventors
- 👤 James L. Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:25
CPC Classifications
B; B82; B82Y; B82Y5/00; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/12; B01J13/125; A; A61; A61K; A61K9/00; A61K9/10; A61K9/127; A61K9/1271; A61K9/1272
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
132 words
A process for producing vesicles wherein a solution containing lipids, amphiphiles and other membrane materials, capable of forming vesicles, in a solvent system is dispersed in an aqueous solution and, subsequently, at least a portion of that solvent system is stripped off, characterized in that said solvent system comprises at least two organic components, S 1 and S 2 , wherein: (a) S 1 is highly soluble in the aqueous solution; (b) S 2 is hydrophobic; (c) S 2 is more volatile than the aqueous solution; (d) the membrane materials are not entirely soluble in S 2 alone; (e) the mixture of S 1 and S 2 forms an interface with the aqueous solution; and (f) the membrane materials may be dissolved in a mixture of S 1 and S 2 .
Claim 2
Dependent Claim
132 words
A process for producing vesicles wherein a solution containing lipids, amphiphiles and other membrane materials, capable of forming vesicles, in a solvent system is dispersed in an aqueous solution and, subsequently, at least a portion of that solvent system is stripped off, characterized in that said solvent system comprises at least two organic components, S 1 and S 2 , wherein: (a) S 1 is highly soluble in the aqueous solution; (b) S 2 is hydrophobic; (c) S 2 is more volatile than the aqueous solution; (d) the membrane materials are not entirely soluble in S 2 alone; (e) the mixture of S 1 and S 2 forms an interface with the aqueous solution; and (f) the membrane materials may be dissolved in a mixture of S 1 and S 2 .
Claim 3
Dependent Claim
22 words
A process according to claim 1 wherein the partition coefficient of S 1 in the aqueous solution is greater than about 0.1.
Claim 4
Dependent Claim
22 words
A process according to claim 2 wherein the partition coefficient of S 1 in the aqueous solution is greater than about 0.5.
Claim 5
Dependent Claim
24 words
A process according to claim 3 wherein the aqueous solution has dissolved in it at least one material to be contained in the vesicles.
Claim 6
Dependent Claim
22 words
A process according to claim 4 wherein the dispersion of membrane solution in the aqueous solution undergoes gentle agitation or no agitation.
Claim 7
Dependent Claim
16 words
A process according to claim 4 wherein the membrane solution is injected into the aqueous solution.
Claim 8
Dependent Claim
31 words
A process according to claim 6 wherein the membrane solution is injected into the aqueous solution through one or more openings having a diameter of about 0.03 to about 200 microns.
Claim 9
Dependent Claim
21 words
A process according to claim 7 wherein the injection openings have a diameter of from about 0.03 to about 20 microns.
Claim 10
Dependent Claim
23 words
A process according to claim 6 wherein the solvent system comprises from about 5% to about 50% by weight of S 1 .
Claim 11
Dependent Claim
23 words
A process according to claim 9 wherein the solvent system comprises from about 50% to about 95% by weight of S 2 .
Claim 12
Dependent Claim
22 words
A process according to claim 10 wherein the partition coefficient of S 1 in the aqueous solution is greater than about 10.
Claim 13
Dependent Claim
18 words
A process according to claim 11 wherein at least one pharmaceutically-active agent is dissolved in the aqueous solution.
Claim 14
Dependent Claim
22 words
A process according to claim 12 wherein the pharmaceutically-active agent is selected from the group consisting of insulin, interferon, or mixtures thereof.
Claim 15
Dependent Claim
24 words
A process according to claim 7 wherein the membrane material is selected from the group consisting of distearoyl lecithin, dipalmitoyl lecithin or mixtures thereof.
Claim 16
Dependent Claim
17 words
A process according to claim 7 wherein the membrane material is a long-chain di-alkyl dimethyl ammonium compound.
Claim 17
Dependent Claim
23 words
A process according to claim 14 wherein S 1 is selected from the group consisting of methanol, ethanol, propanol, isopropanol, and mixtures thereof.
Claim 18
Dependent Claim
25 words
A process according to claim 15 wherein S 2 is selected from the group consisting of hexane, cyclohexane, 2,2-dimethylbutane, pentane, isopentane, 1,1,2-trichlorotrifluoroethane, and mixtures thereof.
Claim 19
Dependent Claim
38 words
A process according to claim 7 wherein after the membrane solution is dispersed in the aqueous solution, the temperature of the dispersion is raised, in a controlled manner, so as to remove substantially all of S 2 .
References Cited (Backward Citations)
DE2237545A1
Cited
US3932657A
Cited
US4183918A
Cited
US4224179A
Cited
US4235871A
Cited
US4308166A
Cited
US4310506A
Cited
US4310505A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-18 | 1987-01-17 | 1987-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-18 | 1991-01-17 | 1991-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-18 | 1995-01-17 | 1995-07-19 | $7700.00 | Window Closed / Lapsed |