Althin Medical, Inc.

Baxter International Inc.

Other

Baxter Healthcare Sa

George Washington

John M Radovich

Kees Ruzius

Thanh Van Nguyen

Lalith K Silva

Melvin Rothberg

Timothy B Meluch

Hamid Jaanine

Raymond Elsen

Lalith Silva

Ben Fernandez

Chung-Yuan Chiang

Anders Althin

Martin E Ketterer

Jonnie Lee

Delores Jordan

Wenli Han

Dibyendu De

The present invention provides, inter alia, a composition useful for producing a homogeneous, semipermeable membrane, the composition comprising a polysulfone semipermeable membrane, the polysulfone semipermeable membrane comprising a mixture of: an ultra-high-molecular-weight hydrophilic polymer, a polysulfone compound and a solvent for the polysulfone compound, and the polysulfone semipermeable membrane having a homogeneous structure such that the polysulfone semipermeable membrane has a substantially uniform structure. Another aspect of this invention discloses methods for fabricating semipermeable membranes by homogeneously mixing the composition, melting the composition, and melt-spinning the molten composition. Another aspect of the present invention includes homogeneous, melt-spun, semipermeable membranes useful for liquid separation processes, such as, but not limited to, microfiltration, ultrafiltration, dialysis, and reverse osmosis.

Melt-spun polysulfone semipermeable membranes and methods for making the same

The present invention discloses, inter alia, a composition useful for producing a hemogeneous, semipermeable membrane, the composition comprising (1) a polysulfone compounds, (2) a solvent, such as sulfolane, antypyrine, &#x3b4;valerolactam, diethyl phthalate, and mixtures thereof, and (3) a non-solvent, such as poly(ethylene glycol), di(ethylene glycol), tri(ethylene glycol), glycerol, and mixtures thereof. Another aspect of this invention discloses methods for fabricating semipermeable membranes by homogeneously mixing the composition of the polysulfone compound, solvent, and non-solvent, melting the composition, and melt-spinning the molten composition. Another aspect of the present invention includes homogeneous, melt-spun, semipermeable membranes useful for liquid separation processes, such as, but not limited to, microfiltration, ultrafiltration, dialysis, and reverse osmosis.

The present invention discloses, inter alia, a composition useful for producing a homogeneous, semipermeable membrane, the composition comprising (1) a polysulfone compound, (2) a solvent, such as sulfolane, antypyrine, &dgr;-valerolactam, diethyl phthalate, and mixtures thereof, and (3) a non-solvent, such as poly(ethylene glycol), di(ethylene glycol), tri(ethylene glycol), glycerol, and mixtures thereof. Another aspect of this invention discloses methods for fabricating semipermeable membranes by homogeneously mixing the composition of the polysulfone compound, solvent, and non-solvent, melting the composition, and melt-spinning the molten composition. Another aspect of the present invention includes homogeneous, melt-spun, semipermeable membranes useful for liquid separation processes, such as, but not limited to, microfiltration, ultrafiltration, dialysis, and reverse osmosis.

Methods are disclosed for making semipermeable membranes from cellulose acetate and for making medical devices therefrom. In the process, a molten liquid comprising cellulose acetate (CA) is extruded to produce a membrane. The solvent and non-solvent are removed from the membrane to produce a semipermeable membrane having a water permeability. The semipermeable membrane is impregnated with a liquid consisting essentially of water to render the semipermeable membrane capable of being stored until time of use without undergoing a substantial loss in water permeability. The semipermeable membrane can be incorporated in a casing in order to produce a medical product, wherein the membrane is impregnated in the product.

Process for making a medical device from a cellulose acetate hollow

Semipermeable membranes are disclosed for purifying aqueous biological fluids. The membranes are particularly suitable for purifying extracorporeal blood via hemodialysis. The membranes, preferably configured as hollow fibers, are made from a hydrophilic polymeric material, preferably cellulose acetate. Features of the membranes include an ultrafiltration coefficient (K.sub.uF) of about 15 to about 55 mL/hr/mmHg/m.sup.2 (thus termed 'high-flux' type membranes), a urea mass transfer coefficient (K.sub.oV (Urea)) of at least 38.times.10.sup.-3 cm/min, and a ratio of K.sub.oV (urea)/K.sub.uF of at least 2.5.times.10.sup.-3. Hollow fibers of such membranes suitable for hemodialysis have a lumen diameter of about 175 to about 210 .mu.m and a wall thickness of about 10 to about 35 .mu.m. According to disclosed methods for making the membranes, a melt comprising about 32 to about 40% w/w cellulose acetate, about 5 to about 10% w/w glycerine, and about 50 to about 67% w/w polyethylene glycol is extruded to make hollow fibers; the fibers are cooled, cold-stretched, water-leached, and replasticized using a glycerine solution.

High-flux hollow-fiber membrane with enhanced transport capability and

Methods are disclosed for making semipermeable membranes from cellulose acetate and for making medical devices therefrom. In the process, a molten liquid comprising cellulose acetate (CA), a solvent for CA, and a non-solvent for CA is extruded to produce a membrane. The solvent and non-solvent are removed from the membrane to produce a semipermeable membrane having a water permeability. The semipermeable membrane is impregnated with a liquid consisting essentially of water to render the semipermeable membrane capable of being stored until time of use without undergoing a substantial loss in water permeability. The semipermeable membrane can be incorporated in a casing in order to produce a medical product, wherein the membrane is impregnated in the product.

Process of making a cellulose acetate semipermeable membrane

Semipermeable membranes are disclosed for purifying aqueous biological fluids. The membranes are particularly suitable for purifying extracorporeal blood via hemodialysis. The membranes, preferably configured as hollow fibers, are made from a hydrophilic polymeric material, preferably cellulose acetate. Features of the membranes include an ultrafiltration coefficient (K.sub.uF) of about 15 to about 55 mL/hr/mmHg/m.sup.2 (thus termed 'high-flux' type membranes), a urea mass transfer coefficient (K.sub.oV (urea)) of at least 38.times.10.sup.-3 cm/min, and a ratio of K.sub.oV (urea)/K.sub.uF of at least 2.5.times.10.sup.-3. Hollow fibers of such membranes suitable for hemodialysis have a lumen diameter of about 175 to about 210 .mu.m and a wall thickness of about 10 to about 35 .mu.m. According to disclosed methods for making the membranes, a melt comprising about 32 to about 40% w/w cellulose acetate, about 5 to about 10% w/w glycerine, and about 50 to about 67% w/w polyethylene glycol is extruded to make hollow fibers; the fibers are cooled, cold-stretched, water-leached, and replasticized using a glycerine solution.

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Miramar, FL, United States of America

George Washington