Patent US5832272A successfully refreshed from Google Patents.
Patent US5955108A successfully refreshed from Google Patents.
US5955108A
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US
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Cross-linked microparticles and their use as therapeutic vehicles
Assignee: Quadrant Drug Delivery Ltd
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Filing: 1997-06-16
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Granted: 1999-09-21
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Expires: 2017-06-16
Abstract
Abstract A sterile powder comprising microparticles, 0.1 to 50 mu m in diameter, obtainable by spray-drying and cross-linking a water-soluble material having free functional groups, is characterized in that the microparticles are hydrophilic, can be reconstituted in water to give a monodisperse suspension, and have retained said groups available for derivatization. The particles are linked to drugs or other functional molecules, and used as vehicles in therapy.
Inventors
- 👤 Andrew Derek Sutton
- 👤 Richard Alan Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:53
CPC Classifications
A; A61; A61K; A61K47/00; A61K47/50; A61K47/69; A61K47/6921; A61K47/6927; A61K47/51; A61K47/62; A61K47/64; A61K47/643
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
74 words
A sterile powder comprising smooth, spherical microparticles of 0.1 to 50 μm in diameter, wherein said microparticles comprise a cross-linked material selected from the group consisting of an amino acid, a polyamino-acid and a polypeptide, the microparticles being hydrophilic and capable of reconstitution in water to give a monodisperse suspension, and wherein said sterile powder additionally comprises a physiologically or diagnostically-active component linked directly or indirectly to the microparticles via free functional groups thereon.
Claim 2
Dependent Claim
74 words
A sterile powder comprising smooth, spherical microparticles of 0.1 to 50 μm in diameter, wherein said microparticles comprise a cross-linked material selected from the group consisting of an amino acid, a polyamino-acid and a polypeptide, the microparticles being hydrophilic and capable of reconstitution in water to give a monodisperse suspension, and wherein said sterile powder additionally comprises a physiologically or diagnostically-active component linked directly or indirectly to the microparticles via free functional groups thereon.
Claim 3
Dependent Claim
71 words
A powder according to claim 1, produced by a process comprising the steps of (i) spray-drying a water-soluble and cross-linkable material selected from the group consisting of an amino acid a polyamino acid and a polypeptide, said material having free functional groups thereon, (ii) cross-linking said material such that said groups are retained in free form, and (iii) linking a physiologically or diagnostically-active component to the cross-linked material via said groups.
Claim 4
Dependent Claim
16 words
A powder according to claim 1, which comprises an additional water-soluble material that facilitates enzymatic biodegradation.
Claim 5
Dependent Claim
25 words
A powder according to claim 1, wherein the active component is a drug, chemical spacer, a ligand for an enzyme or receptor, or an antibody.
Claim 6
Dependent Claim
14 words
A powder according to claim 4, wherein the active component is a cytotoxic agent.
Claim 7
Dependent Claim
14 words
A powder according to claim 5, wherein the microparticles additionally comprise a targeting agent.
Claim 8
Dependent Claim
20 words
A powder according to claim 4, wherein the active component is selected from the group consisting of fibrinogen and thrombin.
Claim 9
Dependent Claim
26 words
A method of wound therapy or surgical repair, which comprises administering to the wound or surgical locus an effective amount of the powder of claim 7.
Claim 10
Dependent Claim
36 words
A powder according to claim 2, wherein step (i) comprises spray-drying a solution of the water-soluble material, and step (ii) comprises cross-linking the spray-dried material with heat and in the presence of less than 4% moisture.
Claim 11
Dependent Claim
23 words
A powder according to claim 1, wherein said free functional groups are selected from the group consisting of amine, hydroxyl, carboxyl and sulfhydryl.
Claim 12
Dependent Claim
22 words
A powder according to claim 10, wherein said free functional groups are selected from the group consisting of amine, hydroxyl and carboxyl.
Claim 13
Dependent Claim
22 words
A powder according to claim 1, wherein the microparticles have a ratio of interquartile range to mean diameter of 0.2 to 0.5.
Claim 14
Dependent Claim
30 words
A powder according to claim 12, wherein 95% of the microparticles are smaller than 6 μm, and 80% of the microparticles are in the range of 1 to 6 μm.
Claim 15
Dependent Claim
30 words
A powder according to claim 12, wherein 90% of the microparticles are smaller than 20 μm, and less than 5% of the microparticles by volume are smaller than 6 μm.
Claim 16
Dependent Claim
13 words
A suspension of microparticles as defined in claim 1, suitable for parenteral administration.
Claim 17
Dependent Claim
30 words
A suspension according to claim 15, wherein the microparticles comprise free functional groups selected from the group consisting of amine, hydroxyl, carboxyl and sulfhydryl said suspension suitable for intravenous administration.
Claim 18
Dependent Claim
32 words
A suspension comprising the powder of claim 12, wherein the microparticles comprise free functional groups selected from the group consisting of an amine, hydroxyl, and carboxyl, said suspension suitable for intraarterial administration.
Claim 19
Dependent Claim
32 words
A method for the treatment of multi-drug resistance in a patient exhibiting a tumor, which comprises administering to the patient an effective amount of the powder of claim 5 or claim 6.
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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) | 2002-09-20 | 2003-03-22 | 2003-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-09-20 | 2007-03-22 | 2007-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-09-20 | 2011-03-22 | 2011-09-21 | $7700.00 | Window Closed / Lapsed |