US4229360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the dehydration of a colloidal dispersion of lipsomes
Assignee: Elan Pharmaceuticals LLC
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Filing: 1978-08-04
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Granted: 1980-10-21
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Expires: 1998-08-04
Abstract
Abstract The invention concerns a process for the dehydration of a colloidal dispersion of liposomes in an aqueous liquid medium, this process being aimed at extending the conservation of the liposomes and to enable their efficient use at a later date. According to this process, there is prepared a mixture of a hydrophilic compound and the liposome dispersion. This mixture is then subjected to a dehydration operation leading to the formation of liposomes in the form of a stable powder which can be stored for a long period and from which a dispersion of liposomes can be reconstituted.
Inventors
- 👤 Michel Schneider
- 👤 Bernard Lamy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:25
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/10; A61K9/127
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
51 words
A process for the dehydration of a colloidal dispersion of liposomes in an aqueous liquid medium, which comprises mixing a hydrophilic compound with the liposome dispersion and dehydrating the mixture to form a stable liposome containing powder which can be stored and reconstituted in an aqueous medium as a liposome dispersion.
Claim 2
Dependent Claim
51 words
A process for the dehydration of a colloidal dispersion of liposomes in an aqueous liquid medium, which comprises mixing a hydrophilic compound with the liposome dispersion and dehydrating the mixture to form a stable liposome containing powder which can be stored and reconstituted in an aqueous medium as a liposome dispersion.
Claim 3
Dependent Claim
42 words
The process of claim 1, in which the mixture is dehydrated by first freezing said mixture of the liposome dispersion and the hydrophilic compound and, thereafter, removing water from said frozen mixture by reduced pressure evaporation to obtain said powder of liposomes.
Claim 4
Dependent Claim
47 words
The process of claims 1 or 2, wherein the liposomes consist essentially of vesicles of a liquid encapsulated in a film of a lipid and said mixture includes, by weight, at least as much of the hydrophilic compound as of the lipid used to form the liposomes.
Claim 5
Dependent Claim
25 words
The process of claim 3 wherein the weight ratio of the hydrophilic compound to the lipid is from 1 to 1 to 4 to 1.
Claim 6
Dependent Claim
24 words
The process of claim 3, wherein said hydrophilic compound is selected from the group comprising dextran, gum arabic, polyvinyl alcohol, polyvinyl pyrrolidone and ox-albumin.
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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) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |