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US5271928A Expired / Lapsed US ⏱️ 0.0 years remaining

Stable microbubbles suspensions injectable into living organisms

Assignee: Bracco Suisse SA
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Filing: 1991-04-02
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Granted: 1993-12-21
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Expires: 2011-04-02
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Abstract

Abstract Gas or air filled microbubble suspensions in aqueous phases usable as imaging contrast agents in ultrasonic echography. They contain laminarized surfactants and, optionally, hydrophilic stabilizers. The laminarized surfactants can be in the form of liposomes. The suspensions are obtained by exposing the laminarized surfactants to air or a gas before or after admixing with an aqueous phase.

Inventors

  • 👤 Michel Schneider
  • 👤 Daniel Bichon
  • 👤 Philippe Bussat
  • 👤 Jerome Puginier
  • 👤 Eva Hybl-Sutherland

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 07:50
CPC Classifications
A; A61; A61K; A61K49/00; A61K49/22; A61K49/222; A61K49/223; A61K49/227

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 70 words
A composition suitable for injection into the bloodstream and body cavities of living beings, comprising a suspension of stabilized air or gas microbubbles in a physiologically acceptable aqueous carrier phase having from about 0.01 to about 20% by weight of one or more dissolved or dispersed surfactants, at least one of said surfactants being a film forming surfactant present in the composition at least partially in lamellar or laminar form.
Claim 2
Dependent Claim 70 words
A composition suitable for injection into the bloodstream and body cavities of living beings, comprising a suspension of stabilized air or gas microbubbles in a physiologically acceptable aqueous carrier phase having from about 0.01 to about 20% by weight of one or more dissolved or dispersed surfactants, at least one of said surfactants being a film forming surfactant present in the composition at least partially in lamellar or laminar form.
Claim 3
Dependent Claim 19 words
The composition of claim 1, wherein the lamellar surfactant is in the form of mono- or pluri-molecular membrane layers.
Claim 4
Dependent Claim 16 words
The composition of claim 1, containing about 10 8 -10 9 bubbles of 0.5-10 μm size/ml.
Claim 5
Dependent Claim 11 words
The composition of claim 1, wherein the surfactant is a phospholipid.
Claim 6
Dependent Claim 26 words
The composition of claim 4, wherein said phospholipid is selected from the group consisting of lecithins, phosphatidic acid, phosphatidyl-choline, phosphatidyl-ethanolamine, phosphatidyl-serine, phosphatidyl-glycerol, phosphatidyl-inositol, cariolipin and sphyngomyelin.
Claim 7
Dependent Claim 36 words
The composition of claim 4, and further comprising a substance affecting the properties of liposomes selected from the group consisting of phosphatidyl-glycerol, dicetyl-phosphate, cholesterol, ergosterol, phytosterol, sitosterol, lanosterol, tocopterol, propyl gallate, ascorbyl palmitate and butylated hydroxy-toluene.
Claim 8
Dependent Claim 45 words
The composition of claim 1, and further comprising a dissolved viscosity enhancer or stabilizer selected from the group consisting of linear and cross-linked poly- and oligo-saccharides, sugars, hydrophilic polymers and iodinated compounds in a weight ratio to the surfactants of between about 1:5 to 100:1.
Claim 9
Dependent Claim 11 words
The composition of claim 7, wherein said iodinated compound is Iopamidol.
Claim 10
Dependent Claim 35 words
The composition of claim 1, wherein the surfactants comprise up to 50% by weight of non-laminar surfactants selected from the group consisting of fatty acids, esters and ethers of fatty acids and alcohols with polyols.
Claim 11
Dependent Claim 23 words
The composition of claim 9, wherein the non-laminar surfactant is selected from the group consisting of polyalkylene glycols, polyalkylenated sugars and polyalkylenated glycerol.
Claim 12
Dependent Claim 90 words
A method for the preparation of a composition as defined in claim 1, said method comprising the steps of: (a) selecting at least one film forming surfactant and converting it into lamellar form; (b) contacting the surfactant in lamellar form with air or an adsorbable or entrapable gas for a time sufficient for that air or gas to become bound by said surfactant; and (c) admixing the surfactant in lamellar form with an aqueous liquid carrier, to form a stable dispersion of air or gas microbubbles in said liquid carrier.
Claim 13
Dependent Claim 32 words
The method of claim 11, wherein step (c) is performed before step (b), step (b) being effected by introducing pressurized air or gas into the liquid carrier and thereafter releasing the pressure.
Claim 14
Dependent Claim 39 words
The method of claim 11, wherein step (c) is brought about by gentle mixing of the components with no shaking, whereby air or gas bound to the lamellar surfactant in step (b) develops into a suspension of stable microbubbles.
Claim 15
Dependent Claim 31 words
The method of claim 11, wherein the aqueous liquid carrier contains dissolved therein stabilizer compounds selected from the group consisting of hydrosoluble proteins, polypeptides, sugars, poly- and oligo-saccharides and hydrophilic polymers.
Claim 16
Dependent Claim 54 words
The method of claim 11, wherein step (a) is effected by coating the surfactant onto particles of soluble or insoluble materials, wherein step (b) is effected by letting the coated particles stand for a while under air or gas and step (c) is effected by admixing the coated particles with an aqueous liquid carrier.
Claim 17
Dependent Claim 33 words
The method of claim 11, wherein step (a) is effected by sonicating or homogenizing under high pressure an aqueous solution of film forming lipids, leading, at least partly, to the formation of liposomes.
Claim 18
Dependent Claim 27 words
The method of claim 16, wherein step (b) is effected by freeze-drying the liposome containing solution and contacting the resulting freeze-dried product with air or a gas.
Claim 19
Dependent Claim 16 words
The method of claim 17, wherein in step (b) the liposome containing solution contains hydrophilic stabilizers.
Claim 20
Dependent Claim 41 words
The method of claim 16, wherein the aqueous solution of film forming lipids also contains viscosity enhancers or stabilizers selected from the group coasting of hydrophilic polymers and carbohydrates in weight ratio relative to the lipids of between 1:5 and 100:1.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-12-20 1997-06-21 1997-12-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-12-20 2001-06-21 2001-12-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-12-20 2005-06-21 2005-12-21 $7700.00 Window Closed / Lapsed

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