US5160669A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making oil filled paucilamellar lipid vesicles
Assignee: Novavax Inc
•
Filing: 1990-10-16
•
Granted: 1992-11-03
•
Expires: 2010-10-16
Abstract
Abstract A new "cold-loading" technique for filling the amorphous central cavity of paucilamellar lipid vesicles with a water immiscible material has been developed. Preformed, substantially aqueous filled paucilamellar lipid vesicles are mixed with the water immiscible material to be encapsulated under intermediate mixing conditions, thereby replacing the aqueous solution with the water-immiscible solution. The "cold-loading" technique is particularly useful for encapsulation of volatiles and heat labile materials.
Inventors
- 👤 Donald F. H. Wallach
- 👤 Rajiv Mathur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:48
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/10; A61K9/127; A61K9/1271; A61K9/1272; A61K9/1277; A61K9/1278; C; C11; C11D; C11D17/00; C11D17/0008; C11D17/0017; C11D17/0021; C11D17/0026; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
103 words
A method of forming a paucilamellar lipid vesicle having a substantially oil-filled amorphous central cavity comprising the steps of: preforming a paucilamellar lipid vesicle having an aqueous material in the amorphous central cavity; mixing said preformed paucilamellar lipid vesicle with a water immiscible material to be incorporated into said central cavity under mixing conditions such that said water immiscible material is incorporated into said preformed vesicle; and separating said paucilamellar lipid vesicle from any of said water immiscible material not incorporated into said central cavity, whereby said amorphous central cavity of said paucilamellar lipid vesicle is substantially filled with said water immiscible material.
Claim 2
Independent Claim
103 words
A method of forming a paucilamellar lipid vesicle having a substantially oil-filled amorphous central cavity comprising the steps of: preforming a paucilamellar lipid vesicle having an aqueous material in the amorphous central cavity; mixing said preformed paucilamellar lipid vesicle with a water immiscible material to be incorporated into said central cavity under mixing conditions such that said water immiscible material is incorporated into said preformed vesicle; and separating said paucilamellar lipid vesicle from any of said water immiscible material not incorporated into said central cavity, whereby said amorphous central cavity of said paucilamellar lipid vesicle is substantially filled with said water immiscible material.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein an indifferent surfactant is provided in addition to the lipid used to form said vesicle.
Claim 4
Dependent Claim
11 words
The method of claim 2 wherein said indifferent surfactant is water-soluble.
Claim 5
Dependent Claim
34 words
The method of claim 3 wherein said water-soluble indifferent surfactant is selected from a group consisting of polyoxyethylene sorbitan esters, sodium dodecyl sulphate, C 12 -C 18 fatty acids, and salts and mixtures thereof.
Claim 6
Dependent Claim
13 words
The method of claim 2 wherein said indifferent surfactant is not water soluble.
Claim 7
Dependent Claim
33 words
The method of claim 1 wherein said water immiscible material to be incorporated in said amorphous central cavity is volatile or heat labile at the temperatures used to preform said paucilamellar lipid vesicle.
Claim 8
Dependent Claim
29 words
The method of claim 6 wherein said water immiscible material is selected from a group consisting of diethyltoluamide, flavor oils, fragrance oils, d-limonene, water immiscible solvents, and mixtures thereof.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein said paucilamellar lipid vesicles have a non-ionic lipid as the primary bilayer-forming material.
Claim 10
Dependent Claim
18 words
The method of claim 1 wherein said paucilamellar lipid vesicles have a phospholipid as the primary bilayer-forming material.
Claim 11
Dependent Claim
24 words
The method of claim 1 wherein said preformed paucilamellar lipid vesicle contains oil in addition to said aqueous material in said amorphous central cavity.
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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) | 1995-11-03 | 1996-05-04 | 1996-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-03 | 2000-05-04 | 2000-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-03 | 2004-05-04 | 2004-11-03 | $7700.00 | Window Closed / Lapsed |