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US4609728A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of treating a cellulosic hollow fiber

Assignee: Gambro Dialysatoren GmbH and Co KG
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Filing: 1983-07-07
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Granted: 1986-09-02
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Expires: 2003-07-07
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Abstract

Abstract Method of treating a cellulosic hollow fiber which is being particularly adapted for use in hemodialysis or a similar extracorporeal treatment of blood. According to the described method the hollow fiber, possibly after rinsing with an alcoholic solution or fluorinated hydrocarbons, is exposed to swelling with use of an aqueous solution prior to drying and/sterilization of the hollow fiber. Examples of aqueous solutions can be water, water/glycerol, and water/glycerol/alcohol. Preferably said aqueous solution contains glycerol in an amount of 4-35%, such as 12-35%, preferably 16-35%. The aqueous solution can be applied to the inside and/or the outside of the hollow fiber so as to bring about a diffusive and/or a convective transport of water and/or glycerol into the hollow fiber wall. The rate of diffusion can be increased by increasing the temperature of the aqueous solution, by increasing the contact time between the aqueous solution and the hollow fiber, or by increasing the glycerol content of the aqueous solution, and the convective transport of said substances is achieved by applying the aqueous solution under pressure. After drying, the hollow fiber can be sterilized either by temperature or by radiation without any substantial loss of permeability characteristics.

Inventors

  • 👤 Kurt Spranger
  • 👤 Bernd A. W. Beck

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 01:53
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; A; A61; A61L; A61L2/00; A61L2/02; A61L2/04; A61L2/06; A61L2/07; A61L2/08; A61L2/16; A61L2/20; B01D65/00; B01D65/02; B01D65/022; B01D67/0095; B01D2321/00; B01D2321/08; B01D2321/34

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 58 words
A process for making a dry, sterile dialyzer, said process comprising providing a dialyzer containing dried cuproammonium regenerated cellulose hollow fibers, treating said hollow fibers in said dialyzer with an aqueous solution including water and glycerol, then drying the hollow fibers in the dialyzer and then sterilizing the dry hollow fibers in the dialyzer by heat or radiation.
Claim 2
Dependent Claim 58 words
A process for making a dry, sterile dialyzer, said process comprising providing a dialyzer containing dried cuproammonium regenerated cellulose hollow fibers, treating said hollow fibers in said dialyzer with an aqueous solution including water and glycerol, then drying the hollow fibers in the dialyzer and then sterilizing the dry hollow fibers in the dialyzer by heat or radiation.
Claim 3
Dependent Claim 26 words
The process of claim 1, wherein said treating step comprises treating said hollow fibers with an aqueous solution comprising a mixture of water, glycerol and alcohol.
Claim 4
Dependent Claim 27 words
The method of claim 1, wherein said treating step comprises causing said aqueous solution to penetrate into substantially every space within the walls of said hollow fibers.
Claim 5
Dependent Claim 22 words
The process of claim 3, wherein said treating step comprises causing said aqueous solution to penetrate into said hollow fibers by diffusion.
Claim 6
Dependent Claim 31 words
The process of claim 4, wherein said treating step is carried out by applying said aqueous solution to either the interior or the exterior of said hollow fibers at increased temperatures.
Claim 7
Dependent Claim 33 words
The process of claim 4, wherein said treating step is carried out by applying said acqueous solution to either the interior or the exterior of said hollow fibers for prolonged periods of time.
Claim 8
Dependent Claim 31 words
The process of claim 4, wherein said treating step is carried out by applying said aqueous solution to either the interior or the exterior of hollow fibers under increased pressure conditions.
Claim 9
Dependent Claim 16 words
The process of claim 1, where said aqueous solution includes from about 4 to 35% glycerol.
Claim 10
Dependent Claim 16 words
The process of claim 1, wherein said aqueous solution includes from about 12 to 35% glycerol.
Claim 11
Dependent Claim 16 words
The process of claim 1, wherein said aqueous solution includes from about 16 to 35% glycerol.
Claim 12
Dependent Claim 36 words
The process of claim 1, wherein said sterilization step is carried out by the application of steam to the dry hollow fibers without bring about any substantial loss of the permeability characteristics of said hollow fibers.
Claim 13
Dependent Claim 36 words
The process of claim 1, wherein said sterilization step is carried out by the application of radiation to the dry hollow fibers without bringing about any substantial loss of the permeability characteristics of said hollow fibers.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-09-01 1990-03-03 1990-09-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-09-01 1994-03-03 1994-09-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-09-01 1998-03-03 1998-09-02 $7700.00 Window Closed / Lapsed

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