US4743449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drug-containing lipid vesicle preparation and method for preparing them
Assignee: Astellas Pharma Inc
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Filing: 1984-09-10
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Granted: 1988-05-10
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Expires: 2004-09-10
Abstract
Abstract Drug-containing lipid vesicle preparations are prepared by adding an aqueous solution or suspension to a phospholipid which contains a lipophilic surfactant to form a mixture, stirring said mixture whereby lipid vesides are formed, then dispersing said vesicles in a dispersion medium to form an emulsion.
Inventors
- 👤 Hiromitsu Yoshida
- 👤 Jiro Fujisaki
- 👤 Seiji Sawai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:19
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/10; A61K9/127; A61K9/1271; A61K9/1272; A61K9/1277
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
50 words
A method for the preparation of a drug-containing lipid vesicle preparation comprising adding an aqueous solution or suspension to a phospholipid which contains a lipophilic surfactant to form a mixture, stirring said mixture whereby lipid vesicles are formed, then dispersing said vesicles in a dispersion medium to form an emulsion.
Claim 2
Independent Claim
50 words
A method for the preparation of a drug-containing lipid vesicle preparation comprising adding an aqueous solution or suspension to a phospholipid which contains a lipophilic surfactant to form a mixture, stirring said mixture whereby lipid vesicles are formed, then dispersing said vesicles in a dispersion medium to form an emulsion.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein said dispersion medium is an aqueous solution of at least one hyrophilic surfactant or is an oily base.
Claim 4
Dependent Claim
38 words
The method of claim 1 wherein said medium is an aqueous solution of at least one hydrophilic surfactant and said emulsion is a liquid further comprising freeze drying or spray drying said emulsion to form a solid preparation.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein said adding is carried out dropwise.
Claim 6
Dependent Claim
12 words
The preparation which is the product of the method of claim 1.
Claim 7
Dependent Claim
12 words
The preparation which is the product of the method of claim 2.
Claim 8
Dependent Claim
12 words
The preparation which is the product of the method of claim 3.
Claim 9
Dependent Claim
12 words
The preparation which is the product of the method of claim 4.
Claim 10
Dependent Claim
33 words
The preparation of claim 5 wherein said vesicles are dispersed in said aqueous solution of said hydrophilic surfactant and said emulsion has been freeze dried or spray dried to form a solid preparation.
Claim 11
Dependent Claim
67 words
A drug-containing lipid vesicle emulsion preparation comprising aggregations of lipid vesicles comprising a. an inner aqueous phase in the form of an aqueous solution or suspension containing a drug therein, and b. a membrane of phospholipid containing a lipophilic surfactant enclosing said aqueous phase, said vesicles dispersed in an aqueous solution of at least one hydrophilic surfactant or in an oily ointment base and constituting an emulsion.
Claim 12
Dependent Claim
67 words
A drug-containing lipid vesicle emulsion preparation comprising aggregations of lipid vesicles comprising a. an inner aqueous phase in the form of an aqueous solution or suspension containing a drug therein, and b. a membrane of phospholipid containing a lipophilic surfactant enclosing said aqueous phase, said vesicles dispersed in an aqueous solution of at least one hydrophilic surfactant or in an oily ointment base and constituting an emulsion.
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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) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |