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US4617271A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for producing immobilized L-asparaginase preparations for the therapy of leukemia

Assignee: Eneos Corp
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Filing: 1983-04-21
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Granted: 1986-10-14
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Expires: 2003-04-21
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Abstract

Abstract This invention relates to a process for producing immobilized L-asparaginase preparations. Its principal object is to produce immobilized L-asparaginase preparations which are excellent in antithrombogenicity and mechanical strength. The present invention is concerned with production of immobilized L-asparaginase preparations by pouring an aqueous solution containing 6% or more of a polyvinyl alcohol with a degree of hydrolysis of 97 mol. % or higher and a viscosity-average degree of polymerization of 1,800 or more an antileukemic asparaginase into a vessel or a mold of an appropriate shape, subjecting the solution to cooling, solidification and molding at a temperature of -15° C. or lower and partially dehydrating the molded mass without thawing to a dehydration ratio of 5% by weight or more and, if desired, immersing the product in water. According to the invention, L-asparaginase can be embedded in a highly hydrous gel excellent in antithrombogenicity and mechanical strength by simple procedures.

Inventors

  • 👤 Masao Nambu

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 08:08
CPC Classifications
C; C12; C12N; C12N11/00; C12N11/02; C12N11/04; A; A61; A61K; A61K38/00; A61K38/16; A61K38/43; A61K38/46; A61K38/50; A61K9/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2027; A61K9/2095; A61P; A61P35/00; C12N11/08; C12N11/082; C12N11/084; C12N11/098

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 99 words
A process for producing immobilized L-asparaginase preparations for the therapy of leukemia which comprises pouring an aqueous solution containing 6% by weight or more of a polyvinyl alcohol with a degree of hydrolysis of 97 mol. % or higher and a degree of polymerization of 1,800 or more and an antileukemic asparaginase into a vessel of a desired shape and subjecting the solution to cooling and solidification at a temperature lower then -15° C., and then partially dehydrating the resulting solidified mass without thawing to a dehydration ratio of 5% by weight or more to obtain a desired gel.
Claim 2
Dependent Claim 99 words
A process for producing immobilized L-asparaginase preparations for the therapy of leukemia which comprises pouring an aqueous solution containing 6% by weight or more of a polyvinyl alcohol with a degree of hydrolysis of 97 mol. % or higher and a degree of polymerization of 1,800 or more and an antileukemic asparaginase into a vessel of a desired shape and subjecting the solution to cooling and solidification at a temperature lower then -15° C., and then partially dehydrating the resulting solidified mass without thawing to a dehydration ratio of 5% by weight or more to obtain a desired gel.
Claim 3
Dependent Claim 14 words
The process according to claim 1 wherein heparin is added to the aqueous solution.
Claim 4
Dependent Claim 25 words
The process according to claim 1 or 2 wherein concentration of the polyvinyl alcohol in the aqueous solution is from 6 to 25% by weight.
Claim 5
Dependent Claim 21 words
The process according to any one of claims 1-3 wherein the cooling, solidification and molding temperature is -35° C. or below.
Claim 6
Dependent Claim 23 words
The process according to any one of claim 1-4 wherein dehydration ratio in the partial dehydration step is 15% by weight or more.
Claim 7
Dependent Claim 18 words
The process according to any one of claims 1-5 wherein the partial dehydration is conducted by vacuum dehydration.
Claim 8
Dependent Claim 37 words
The process according to any one of the claims 1-6 wherein the water content of the obtained gel is increased by immersing said gel in water to give a water content of 45 to 92% by weight.

References Cited (Backward Citations)

US3859169A Cited
JPS5052276A Cited
JPS528071A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-10-13 1990-04-14 1990-10-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-10-13 1994-04-14 1994-10-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-10-13 1998-04-14 1998-10-14 $7700.00 Window Closed / Lapsed

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