Patent US4348787A successfully refreshed from Google Patents.
Patent US4950432A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4950432A Expired / Lapsed US ⏱️ 0.0 years remaining

Polyene microlide pre-liposomal powders

Assignee: The University of Texas System
•
Filing: 1987-10-16
•
Granted: 1990-08-21
•
Expires: 2007-10-16
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The present invention involves a process for producing fine powder suitable for the preparation of antifungal polyene microlide-containing liposomes upon suspension in an aqueous solution. This process comprises the following steps. Quantities of polyene macrolide and phospholipids are dissolved respectively in a first solvent and a second solvent to form a first solution and a second solution. The first solution and the second solution are mixed in a desired ratio to form a mixture. The first solvent and the second solvent are then removed from the mixture, for example by evaporation, to form a residue. The residue is then dissolved in a third solvent comprising tertiary butanol and methylene chloride to form a third solution. The third solvent is then removed from the third solution to form a remnant. The remnant is then dissolved in a solvent consisting essentially of tertiary butanol to form a fourth solution. The fourth solution is then filtered through a filter having orifices of between about 0.05 and 0.5 micrometers in diameter to produce a filtrate. The filtrate is lyophilized to remove the tertiary butanol and a fine powder remains. This fine powder may be used to form polyene macrolide-containing liposomes by simple incubation or suspension in an aqueous solution.

Inventors

  • 👤 Reeta Mehta
  • 👤 Gabriel Lopez-Berestein

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 11:52
CPC Classifications
A; A61; A61K; A61K31/00; A61K31/70; A61K9/00; A61K9/10; A61K9/127; A61K9/1277; A61P; A61P31/00; A61P31/04; A61P31/10

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 186 words
A process for producing a powder which forms liposomes comprising an antifungal polyene macrolide upon suspension in an aqueous solution, said process comprising the steps of: (a) dissolving antifungal polyene macrolide and phospholipids in a quantity of first organic solvent and a quantity of second organic solvent respectively, to form a first solution and a second solution; (b) mixing the first solution and the second solution to form a mixture; (c) removing the first organic solvent and the second organic solvent from the mixture to form a residue; (d) dissolving the residue in a quantity of a third organic solvent to form a third solution, wherein the third organic solvent comprises tertiary butanol and methylene chloride; (e) extracting the third organic solvent from the third solution to leave a remnant; (f) forming a fourth solution by dissolving the remnant in a solvent consisting essentially of tertiary butanol; (g) passing the fourth solution through a filter having orifices with diameters of between about 0.05 um and about 0.5 um to produce a filtrate; and (h) lyophilizing the filtrate to remove the solvent consisting essentially of tertiary butanol.
Claim 2
Dependent Claim 186 words
A process for producing a powder which forms liposomes comprising an antifungal polyene macrolide upon suspension in an aqueous solution, said process comprising the steps of: (a) dissolving antifungal polyene macrolide and phospholipids in a quantity of first organic solvent and a quantity of second organic solvent respectively, to form a first solution and a second solution; (b) mixing the first solution and the second solution to form a mixture; (c) removing the first organic solvent and the second organic solvent from the mixture to form a residue; (d) dissolving the residue in a quantity of a third organic solvent to form a third solution, wherein the third organic solvent comprises tertiary butanol and methylene chloride; (e) extracting the third organic solvent from the third solution to leave a remnant; (f) forming a fourth solution by dissolving the remnant in a solvent consisting essentially of tertiary butanol; (g) passing the fourth solution through a filter having orifices with diameters of between about 0.05 um and about 0.5 um to produce a filtrate; and (h) lyophilizing the filtrate to remove the solvent consisting essentially of tertiary butanol.
Claim 3
Dependent Claim 19 words
The process of claim 1 wherein the antifungal polyene macrolide is nystatin, amphotericin B, partricin or a derivative thereof.
Claim 4
Dependent Claim 15 words
The process of claim 1 wherein the antifungal polyene macrolide is nystatin or amphotericin B.
Claim 5
Dependent Claim 13 words
The process of claim 1 wherein the antifungal polyene macrolide is amphotericin B.
Claim 6
Dependent Claim 12 words
The process of claim 1 wherein the antifungal polyene macrolide is nystatin.
Claim 7
Dependent Claim 20 words
The process of claim 1 wherein the phospholipids are one or more of phosphatidylcholine, phosphatidylserine, phosphatidylglycerol, sphingomyelin and phosphatidic acid.
Claim 8
Dependent Claim 12 words
The process of claim 1 wherein the phospholipids comprise DMPC and DMPG.
Claim 9
Dependent Claim 17 words
The process of claim 1 wherein the phospholipids consist essentially of DMPC and DMPG in 7:3 ratio.
Claim 10
Dependent Claim 11 words
The process of claim 1 wherein the first solvent is methanol.
Claim 11
Dependent Claim 11 words
The process of claim 1 wherein the second solvent is chloroform.
Claim 12
Dependent Claim 40 words
The process of claim 1 wherein step (b) is defined further as: mixing the first solution and the second solution to form a first mixture having a ratio of antifungal polyene macrolide to phospholipid between about 1:5 and about 1:50.
Claim 13
Dependent Claim 37 words
The process of claim 1 wherein step (b) is defined further as: mixing the first solution and the second solution to form a first mixture having a ratio of antifungal polyene macrolide to phospholipid of about 1:10.
Claim 14
Dependent Claim 47 words
The process of claim 1 wherein step (c) is defined further as: removing the first solvent and the second solvent from the first mixture by subjecting the first mixture to solvent evaporation under reduced pressure and at a temperature between about 35° C. and about 45° C.
Claim 15
Dependent Claim 27 words
The process of claim 1 wherein, prior to the passing step, the fourth solution is clarified by warming to between about 50° C. and about 70° C.
Claim 16
Dependent Claim 25 words
The process of claim 1 wherein the third organic solvent comprises tertiary butanol and methylene chloride in a ratio between about 2:1 and about 1:40.
Claim 17
Dependent Claim 16 words
The process of claim 1 defined further wherein the filter has orifices of about 0.2 um.
Claim 18
Dependent Claim 23 words
The process of claim 1 wherein the antifungal polyene macrolide and phospholipids are in a ratio of between about 1:5 and about 1:20.
Claim 19
Dependent Claim 21 words
The process of claim 1 wherein the antifungal polyene macrolide and phospholipids are in a ratio of about 1 to 10.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-08-20 1994-02-19 1994-08-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-08-20 1998-02-19 1998-08-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-08-20 2002-02-19 2002-08-21 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag