Polysulfone hollow fiber semipermeable membrane

A method of manufacturing a polysulfone hollow fiber membrane the hollow fiber membrane being capable of allowing selective passage, across said membrane from said internal to said external periphery thereof, of said undesired material, the hollow fiber membrane characterized by

• (i) an albumin permeability no more than 0.5%;
• (ii) per membrane area of 1.6 m.sup.2, an in vitro urea clearance of at least 195 ml/min;
• (iii) per membrane area of 1.6 m.sup.2, an in vitro phosphorus clearance of at least 180 ml/min;
• and
• (iv) per membrane area of 1.8 m.sup.2, a .beta..sub.2 -microglobulin clearance of at least 44 ml/min, which method comprises spinning hollow fibers from a spinning solution comprising a polysulfone, a hydrophilic polymer, a solvent for each of the polysulfone and hydrophilic polymer and water, which spinning solution has a viscosity x (poise) at 30.degree. C. within the range of 25-130 poise and a quantity y (wt %) of water present in the spinning solution within the range satisfying the formula
• -0.01x+1.45.ltoreq.y.ltoreq.-0.01x+2.25.

A method of manufacturing a polysulfone hollow fiber membrane hemodialyzer module, the hollow fiber membrane being capable of allowing selective passage, across said membrane from said internal to said external periphery thereof, of said undesired material, the hollow fiber membrane characterized by

• (i) an albumin permeability no more than 0.5%;
• (ii) per membrane area of 1.6 m.sup.2, an in vitro urea clearance of at least 195 ml/min;
• (iii) per membrane area of 1.6 m.sup.2, an in vitro phosphorus clearance of at least 180 ml/min;
• and
• (iv) per membrane area of 1.8 m.sup.2, a .beta..sub.2 -microglobulin clearance of at least 44 ml/min, which method comprises spinning hollow fibers from a spinning solution comprising a polysulfone, a hydrophilic polymer, a solvent for each of the polysulfone and hydrophilic polymer and water, which spinning solution has a viscosity x (poise) at 30.degree. C. within the range of 25-130 poise and a quantity y (wt %) of water present in the spinning solution within the range satisfying the formula
• -0.01x+1.45.ltoreq.y.ltoreq.-0.01x+2.25,
• and thereafter incorporating the membrane in a module.

A method of manufacturing a polysulfone hollow fiber membrane hemodialyzer module comprising a housing and, disposed within the housing, a hollow fiber membrane, which housing has at least a dialysate inlet to allow entry into the housing of dialysate and which hollow fiber membrane has an internal periphery defining a blood flow conduit and an external periphery for contact thereof with the dialysate in the housing, the hollow fiber membrane being capable of allowing selective passage, across said membrane from said internal to said external periphery thereof, of said undesired material, the hollow fiber membrane characterized by

• (i) an albumin permeability no more than 0.5%;
• (ii) per membrane area of 1.6 m.sup.2, an in vitro urea clearance of at least 195 ml/min;
• (iii) per membrane area of 1.6 m.sup.2, an in vitro phosphorus clearance of at least 180 ml/min, and
• (iv) per membrane area of 1.8 m.sup.2, a .beta..sub.2 -microglobulin clearance of at least 44 ml/min,
• which method comprises (1) spinning, from a spinning solution containing a polysulfone and a hydrophilic polymer hollow fibers, (2) impregnating the hollow fibers with a wetting agent, (3) forming a bundle of the hollow fibers with spacers introduced therebetween to prevent adhesion of the hollow fibers to one another, (4) inserting the bundle of hollow fibers into a hemodialysis module case, (5) potting the module case to form the hemodialysis module, (6) washing off the wetting agent, and then (7) sterilizing the module.