JPH08168524A - Production of blood dialyzer - Google Patents

Abstract

PURPOSE: To provide a method for efficiently producting a blood dialyzer in a half-wet state of dry state having a good transportation/preservation property without the problem of freezing at a low temp. from a blood dialyzer of a wet state packed with water (or an aq. soln.). CONSTITUTION: The liquid packed in the dialyzer is physically removed without drying hollow fiber from the blood dialyzer in the wet state packed with the water (or the aq. soln.) and thereafter, an aq. moisture retaining agent is passed to the core parts of the hollow yarn and the inside of the hollow yarn is impregnated with the aq. moisture retaining agent in a manner as not to ooze the aq. moisture retaining agent to the outside from the outside walls of the hollow yarn. The aq. moisture retatining agent remaining in the core parts of the hollow fiber is therafter physically removed without drying the hollow fiber and further, the hollow fiber is dried at need. As a result, the blood dialyzer in the half-wet state or dry state having the good transportation/preservation property without the problem of freezing at a low temp. is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a semi-wet or dry hemodialyzer. More specifically, from a hemodialyzer that contains a polymer hollow fiber as a hemodialysis membrane and is filled with water (or an aqueous solution), the hollow fiber contains an aqueous solution of a moisturizer and other parts are The present invention relates to a method for producing a semi-wet hemodialyzer that does not substantially contain the aqueous solution and a method for drying the hemodialyzer to produce a dry hemodialyzer.

[0002]

2. Description of the Related Art Hemodialysis membranes were used initially to remove low molecular weight substances such as urea and creatine from blood as a substitute for renal function in patients with impaired renal function.
In recent years, so-called high-performance hollow fiber dialysis membranes have been developed that can efficiently remove medium molecular weight proteins such as β ₂ microglobulin, and their importance is increasing.

Such high-performance hollow fiber dialysis membranes are generally classified into a dry method and a semi-dry semi-wet (dry-wet) method from the manufacturing method (spinning method), and particularly the latter semi-dry semi-wet (dry-wet) method.
The method according to the method is preferably used because it shows good performance.

When a hollow fiber is produced by such a semi-dry semi-wet (dry-wet) method, a core liquid is used to form the hollow portion of the fiber, and the core liquid is a non-liquid such as liquid paraffin or isopropyl myristate. Aqueous solutions and water solutions of organic solvents with the same composition as coagulation baths and water have been widely used. Of these, non-water-soluble liquids such as liquid paraffin and isopropyl myristate are preferred from the viewpoint of the smoothness of the inner surface of the resulting hollow fiber and the stability in the spinning process.

Most of the core liquid composed of these non-water-soluble liquids can be removed from the inside of the hollow fiber by physical means such as centrifugation or pressure extrusion after spinning the hollow fiber. However, since some core liquid remains adhered to the hollow fibers, cleaning is performed by passing a cleaning solvent such as CFC, but CFC is difficult to recover due to ozone layer depletion and low boiling point. Have a

As a means for solving this problem, the inventors of the present invention first (1) wash and remove the non-water-soluble core liquid such as liquid paraffin and isopropyl myristate of the core liquid with isopropanol (isopropyl alcohol), Then, a method of rinsing isopropanol with water (Japanese Patent Application No.
No. 149249), (2) a method of washing the above non-water-soluble core liquid with an aqueous surfactant solution, and then rinsing with water to remove the surfactant and prevent foaming (Japanese Patent Application No. 5-1).
No. 53576) and (3) Method of physically removing non-water-soluble core liquid with compressed air containing water droplets (Japanese Patent Application No. 6-307605).
No.) etc.

In any of these methods, since hollow fiber moisturizers such as glycerin are eluted during washing, water (or an aqueous solution) is filled in the dialyzer, and further sterilized by gamma ray irradiation, if necessary. It is provided to users such as hospitals as a so-called wet hemodialyzer (Japanese Patent Application No. 6-
56568).

[0008] Such a wet hemodialyzer is convenient because it does not require the work of wetting the dialysis membrane and removing air bubbles when it is used in a hospital or the like, but in cold regions it is transported and frozen for filling water. Not only is it difficult to store, but the weight of the hemodialyzer is large, which makes it inconvenient to transport and handle. Also,
Wet hemodialyzers tend to have reduced dialysis performance during storage and during sterilization.

A hemodialyzer that is in a wet state for some reason other than cleaning the core fluid has the same problem.

[0010]

The main object of the present invention is to:
By subjecting such a wet hemodialyzer to a specific treatment, it is relatively lightweight and has no problem of freezing of filling water even in cold regions, and has excellent stability for storage and sterilization treatment. A method for manufacturing a container is provided. Specifically, a method for efficiently producing a semi-wet hemodialyzer having the above advantages from a wet hemodialyzer filled with water (or an aqueous solution) in the hemodialyzer, and further It is to provide a method for producing a dry hemodialyzer from a semi-wet hemodialyzer.

[0011]

Means for Solving the Problems The present invention achieves the above object, and comprises a hemodialyzer in which a hollow fiber for hemodialysis is incorporated and which is filled with water (or an aqueous solution).
After physically removing the water (or the aqueous solution) filled in the dialyzer under the condition that the hollow fiber is not dried, (b) the humectant aqueous solution is passed through the hollow fiber core, and at that time, , The hollow fiber is impregnated with the aqueous solution of the moisturizing agent so that the aqueous solution of the moisturizing agent does not exude from the outer wall of the hollow fiber to the outside. A method for producing a semi-wet hemodialyzer by physically removing the hemodialyzer under non-drying conditions, and further (d) drying the semi-wet hemodialyzer to contain water in the hollow fiber. Is a method of producing a hemodialyzer in a dry state by removing at least a part thereof.

More specifically, the present invention is a hemodialyzer containing a hollow fiber for hemodialysis spun using a non-water-soluble liquid as the core liquid, wherein the core liquid adheres to and remains in the hollow fiber. Is washed with a water-soluble organic solvent such as isopropanol, then washed with water, washed with an aqueous solution of a surfactant and then with water, or washed with a water / compressed air mixed fluid.
A method for producing a hemodialyzer in a semi-wet state or a dry state from a hemodialyzer filled with water (or an aqueous solution) for some reason to be in a wet state. The filling water of, under the condition that the hollow fiber does not dry,
The step of physically removing, (b) the aqueous moisturizing agent solution is passed through the hollow fiber core, and at that time, the blood side is placed on the dialysate side so that the aqueous moisturizing agent solution does not seep out from the outer wall of the hollow fiber. In comparison, a step of impregnating the hollow fiber with an aqueous solution of a moisturizing agent under a pressurized state or a light negative pressure state, and (c) an aqueous solution of a moisturizing agent remaining in the core of the hollow fiber under the condition that the hollow fiber is not dried, By physically performing the steps of removing,
A semi-wet hemodialyzer is prepared, and (d) if necessary, the semi-wet hemodialyzer is dried to remove at least a part (preferably most) of the water content contained in the hollow fiber. Except that the hemodialyzer in a dry state is used.

Here, the "semi-wet hemodialyzer" means
A hemodialyzer in which the inside of the hollow fiber (the peripheral wall portion surrounding the core of the hollow fiber) contains a moisturizer aqueous solution and is not dried, and preferably a portion other than the inside of the hollow fiber, for example, the core of each hollow fiber Part or outer periphery, between the fibers in the hollow fiber bundle or in the space between the outer periphery of the hollow fiber bundle and the inner periphery of the dialysis container, a hemodialyzer in which water or aqueous solution does not substantially remain. And 10 to 500% by weight, preferably 100 to 300% by weight, based on the weight (dry) of the hollow fiber material. Further, the "dry hemodialyzer" means that the above-mentioned semi-wet hemodialyzer is dried and the moisture content of the hollow fiber is kept at room temperature (0 to 40 ° C) and normal humidity (0-40 ° C) after the moisturizer is applied. 20
-80% RH) refers to a hemodialyzer that is kept below the equilibrium water content. Although the maximum moisture content varies depending on the type of humectant and the membrane material, it is preferably dried to a moisture content of 90% by weight or less based on the total weight of the hollow fiber material and the humectant aqueous solution.

The material of the hollow fiber membrane used in the hemodialyzer in the method of the present invention is not particularly limited as long as it can be formed into a hollow fiber for dialysis, but preferable specific examples include cellulose esters and the like. Regenerated cellulose, polysulfone,
Polyacrylonitrile, polycarbonate, polyamide and the like, and among these, particularly preferred hollow fibers can be obtained when a non-water-soluble core liquid is used in the spinning step, such as cellulose diacetate and cellulose ester such as cellulose triacetate. Classes are preferred.

The above polymer is uniformly dissolved together with a solvent and a pore-forming agent to prepare a spinning dope (spinning dope), and a double tube nozzle is used, and a non-water-soluble liquid is supplied as a core liquid to the center of the spinning dope. A hollow fiber having a dialysis function is stably spun by a method in which the above spinning dope is supplied and discharged to the outside and introduced into a coagulation bath to coagulate, for example, a semi-dry semi-wet spinning method.

In this case, examples of the water-insoluble liquid used as the core liquid include aliphatic paraffins having 10 to 30 carbon atoms, higher fatty acid esters and aromatic hydrocarbons having 7 to 10 carbon atoms. These may be used alone or in a mixture. Of these, aliphatic paraffins having 16 or more carbon atoms and higher aliphatic esters having 20 or more carbon atoms are often solid at room temperature, and thus need to be heated and melted during spinning.

The water-insoluble liquid which is particularly preferably used as the core liquid in the method of the present invention has 10 to 10 carbon atoms which is liquid at room temperature.
15 liquid paraffin, isopropyl myristate, toluene, xylene and the like. Among these core fluids,
Liquid paraffin, which is insoluble in the coagulation bath aqueous solution and at the same time completely immiscible with the spinning dope, is the most suitable from the viewpoints of maintaining the shape of the hollow fiber in the spinning process, smoothness of the inner surface of the hollow fiber, and hollow fiber strength. Used.

In the method of the present invention, a hemodialyzer is produced using the hollow fiber spun in this manner, but the non-water-soluble core liquid used during spinning is contained in the core (hollow part) of the hollow fiber. It has to be removed first. Therefore, as much core liquid as possible is removed by physical means such as free fall, pressure extrusion, and centrifugal separation. In this case 2
It is also possible and effective to combine more than one means, for example, it is possible to perform centrifugal separation after free fall and / or pneumatic extrusion, and it is effective.

After that, before or after the hollow fiber bundle is stored and adhered and fixed in a dialysis container (case), the core liquid remaining on the hollow fibers is washed and removed. (1) A method of washing and removing non-water-soluble core liquid such as liquid paraffin and isopropyl myristate in the core liquid with (1) isopropanol (isopropyl alcohol), and then rinsing isopropanol with water (Japanese Patent Application No. No. 5-149249), (2) A method of washing the above non-water-soluble core liquid with an aqueous solution of a surfactant, and subsequently rinsing with water to remove the surfactant and prevent foaming (Japanese Patent Application No. 5-153576). ) And (3) After assembling the dialyzer (module), water is passed through the hollow fiber in the dialyzer to moisten the fiber, and then the residual adhesion of the hollow fiber is passed through compressed air containing water drops. That the core liquid physically method of removing (Japanese Patent Application No. 6-307605) and the like are preferably employed.

Preferably, the core liquid contained in the core portion (hollow portion) of the spun hollow fiber is first subjected to 80% by weight or more of the core liquid by a physical means such as spontaneous dropping, pressure extrusion and / or centrifugation. After removing 90% by weight or more, preferably, the hollow fiber bundle is housed in a dialysis container (case) and fixed by adhesion to assemble a dialyzer (module). After this so-called molding step, the core liquid remaining attached to the hollow fibers in the dialyzer is washed and removed by the methods such as (1), (2), and (3) described above, and then continuously stored in the dialyzer. Water (or an aqueous solution in which additives are added as necessary) is filled to prepare a wet dialyzer.

According to the method of the present invention, the wet dialyzer thus produced is used, and at least the following (a)
A semi-wet state dialyzer is produced by performing the steps (b) and (c), and a dry state dialyzer is produced by adding the step (d) below, if necessary. (A) a step of physically removing filling water into the hemodialyzer (the filling water may optionally contain an additive) under conditions in which the hollow fiber does not dry; (b) a hollow fiber core A step of passing an aqueous solution of a moisturizing agent through the portion and at the time of impregnating the aqueous solution of the moisturizing agent into the outside of the outer wall of the hollow fiber to impregnate the aqueous solution of the moisturizing agent into the hollow fiber membrane, (c) the hollow fiber Physically removing the aqueous humectant solution remaining in the core part (hollow part) of the hollow fiber under the condition that the hollow fiber does not dry, (d) at least a part of the water content of the aqueous humectant solution in the hollow fiber, preferably In the step of drying and removing most of the above-mentioned step (a),
First, the filling water in the hemodialyzer in a wet state is discharged and removed by a physical means such as spontaneous fall, pressure extrusion, and centrifugal separation. At this time, it is necessary to carry out under the condition that the hollow fiber is not dried. Here, the "condition not to dry" refers to a state containing 10 to 500% by weight, preferably 100 to 300% by weight, of water based on the weight (dry) of the hollow fiber material. Here, as the means for discharging the filling liquid from the dialyzer, suitable physical means such as free fall, extrusion by compressed air, and centrifugal separation are adopted, but these may be used in combination of two or more kinds, for example, Centrifugation may be further carried out after performing free fall or pressure extrusion. This step (a) is suitably carried out at 0 ° C to 70 ° C, preferably room temperature to 50 ° C.

Next, in the step (b), the humectant aqueous solution is passed through the hollow fiber core (hollow portion), and at that time, the humectant aqueous solution is prevented from seeping out from the outer wall of the hollow fiber. Then, the inside of the hollow fiber membrane is impregnated with the moisturizer aqueous solution.

As the moisturizing agent, one which is nontoxic, water-soluble, has a high boiling point and is easily impregnated into the hollow fiber is used.
Preferable specific examples include glycerin, ethylene glycol, propylene glycol, water-soluble polyethylene glycol and polypropylene glycol. These are usually 30 to 90% by weight, preferably 50 to
Used as an aqueous solution of 80% by weight. This aqueous humectant solution is used at room temperature or heated to have a low viscosity before use.

In order to impregnate the inside of the hollow fiber with the aqueous moisturizing agent, it is appropriate to set the pressure on the blood side into which the liquid is injected to a positive pressure or a light negative pressure as compared with the pressure on the dialysate side, and it is preferable. -500 to 2000 mmHg, particularly preferably 10
Pressurized in the range of 760 mmHg.

In the method of the present invention, at this time, it is necessary to set the condition that the aqueous solution of the humectant does not leak from the outer wall of the hollow fiber to the dialysate side, and an appropriate pressure is selected in consideration of the material and thickness of the membrane. Should be. For example, in the case of a cellulose triacetate hollow fiber, it is preferable that the liquid inlet side has a pressure range of 50 to 560 mmHg. On the other hand, the pressure on the liquid outlet side may be a slight negative pressure.

As described above, it is appropriate to apply pressure from the blood side for the purpose of promoting the impregnation of the aqueous solution of the humectant into the hollow fiber membrane. At this time, however, the blood side may be made to have an extreme negative pressure. If the pressure is excessively applied from the dialysate side, the thread may be crushed, making it difficult to uniformly treat the moisturizer.

The impregnation treatment temperature in this step (b) is usually 0.
C.-70.degree. C. is adopted, and it is preferable to carry out at room temperature-50.degree. The processing time is preferably 30 seconds to 20 minutes, and particularly preferably 1 to 10 minutes.

After impregnating the inside of the hollow fiber membrane (inside the peripheral wall of the hollow fiber) with the aqueous solution of the moisturizing agent in this manner, in the step (c), the aqueous solution of the moisturizing agent remaining in the core of the hollow fiber is removed by the hollow fiber. Physically remove under non-drying conditions.

The physical means adopted in this step are:
The same means as in the above step (a) can be adopted, but if necessary, in order to push out the residual liquid of the moisturizer aqueous solution in the hollow fiber,
An operation of once pressurizing from the blood side and releasing at a stretch to expel excess liquid along the membrane and along the core (hollow portion) may be added.

The semi-wet dialysis machine produced as described above is further subjected to the above step (d) to obtain a dry dialysis machine, which can be dried by ventilation, heating (heating with hot air,
Although it can be performed by heating with a heater, heating with high frequency, or the like, or steam drying (using a solvent vapor or the like), a method of ventilating the dialysate side and / or the blood side is preferably adopted because of its drying efficiency.

Thus, according to the method of the present invention, a semi-wet hemodialyzer or a dry hemodialyzer can be efficiently produced.

In the method of the present invention, after the semi-wet or dry hemodialyzer is produced as described above, it can be sterilized by ethylene oxide, heating, gamma ray irradiation, etc. Treatment is preferred.

During gamma ray sterilization, it is possible to prevent deterioration of the dialysis membrane by adding a gamma ray resistant stabilizer to the aqueous moisturizing agent solution in step (c) in advance. Specific examples of the stabilizer for such a membrane include propylene glycol, polypropylene glycol, sodium dihydrogen phosphate, disodium hydrogen phosphate or a mixture thereof, and a pH adjuster.

[0034]

As described above, according to the method of the present invention, the water-insoluble liquid used as the core liquid of the hollow fiber is treated with a water-soluble liquid such as isopropyl alcohol without using a solvent such as Freon which is environmentally abandoned. After washing with a solvent or a surfactant aqueous solution, further washing with water, or a hemodialyzer that has become wet by washing with pressurized air and water, a dialyzer in which a moisturizer is added again to a semi-wet state, Furthermore, a dried dialyzer can be efficiently manufactured by drying this. And, such a semi-wet or dry dialyzer does not have the problem of freezing at low temperature and has the advantage that it is easy to transport because it is lightweight, and compared to a wet dialyzer. It also has the advantage of excellent storage stability.

[0035]

EXAMPLES Hereinafter, the method of the present invention will be described more specifically with reference to Examples and Comparative Examples. However, these examples and comparative examples are for helping understanding of the present invention, and the scope of the present invention is not limited by these descriptions.

The dialysis performance of the hollow fibers in the examples was measured as follows. (Dialysis performance measuring method of hollow fiber) As dialysis performance of hollow fiber, water permeability (UFR), urea dialysis property (DA urea), dextran 10,000 dialysis property (DA 10,000), dextran 70,000 Flue coefficient (SC 70,000) Was evaluated. A dialyzer with an effective area of 1.5 m ² was used for evaluation. The specific measurement conditions are shown below. (A) UFR: Pure water 20 at 35 ° C. with a differential pressure of 300 mmH ₂ O
It was determined by measuring the time required for pressure filtration of mL (unit: ml / m ² / h / mmHg). (B) DA urea: From the difference in concentration of the urea aqueous solution at the inlet and the outlet when the 0.01 wt% urea aqueous solution was passed from one end face of the inner hollow fiber bundle to the other end face at a flow rate of 200 mL / min. It was calculated (unit: ml / min). (C) DA 10,000: A 0.02 wt% aqueous solution of dextran 10,000 was used as a dialysis solution, and the calculation was performed in the same manner as the urea dialysis property (unit: ml / min). (D) SC 70,000: It was calculated by using a 0.01 wt% aqueous solution of dextran 70,000 as a stock solution and measuring the concentration of dextran 70,000 permeated through the membrane under a pressure of 10 mmHg.

The parts or% shown in the examples are based on weight unless otherwise specified.

[Examples 1 and Comparative Example 1] A bundle of cellulose triacetate hollow fibers spun using liquid paraffin as a core liquid was suspended and allowed to stand in a dryer at 50 ° C, and the liquid paraffin was naturally discharged from one end surface of the hollow fiber. 3 more after dropping
About 95% of the liquid paraffin inside the hollow fiber was removed by centrifugation at 000 rpm. Thereafter, the hollow fiber bundle was housed in a dialysis container (case), the end of the yarn bundle was sealed with a urethane resin, and a urethane curing reaction was carried out at 50 ° C. for 15 hours.

After passing 1 L of water through the inner surface of the hollow fiber-containing dialyzer (module) thus obtained to wet it,
Pressurized air-water mixture (pressurized air containing water droplets) inside the hollow fiber
Was passed through at a flow rate of 100 L / min of air + 125 mL / min of water for 10 minutes to physically remove the liquid paraffin, and then filled with water to prepare a hemodialyzer (module) in a wet state.

The pressure of 300 mmHg was applied three times alternately on the blood side / dialysate side of this dialyzer (module) to remove the filling water. Therefore, the dialysate side should be capped with 6 as an aqueous solution of moisturizer.
A 0% glycerin aqueous solution was passed through the blood side at a flow rate of 200 mL / min at a positive pressure for 5 minutes, and finally, pressurized air was blown from the top and bottom for 1 minute at a flow rate of 200 mL / min. When the water droplets in the dialysis container (case) were finely dispersed, they disappeared due to the hygroscopic effect of the glycerin solution that penetrated the thread. Further, the droplets of the aqueous glycerin solution remaining in the thread penetrated into the membrane and disappeared when a pressure of 2 atm was applied from the blood side.

Propylene glycol was added to the filling solution of this dialyzer to perform gamma ray irradiation with an irradiation dose of 25KGy,
Sterilized.

In the semi-wet dialyzer (module) thus obtained, the moisture content of the hollow fiber was 140 parts per 100 parts of the thread material (cellulose triacetate), and the dialysis performance immediately after its preparation and after storage was as shown in the table. It was as shown in 1. Although this dialyzer was lightweight, it did not change from the performance of the dialyzer in the wet state before gamma-ray sterilization (Comparative Example 1). Furthermore, as is clear from Table 1, the SC70,000 value is larger than that of the dialyzer of the comparative example 1 which is not frozen even when stored at low temperature and is gamma-ray sterilized and stored in the wet state of Comparative Example 1. No leaks were seen,
It was found that it is stable in terms of performance and has high storage stability in terms of quality (leak surface).

[0043]

[Table 1]

[Examples 2 and 3] The same treatment as in Example 1 was carried out by using a 60% polyethylene glycol aqueous solution and a 60% propylene glycol aqueous solution instead of the humectant aqueous solution used in Example 1. A wet dialyzer was made.

When the performance stability of each dialyzer was evaluated, the results shown in Table 2 were obtained. As is clear from Table 2, the semi-wet hemodialyzer according to the method of the present invention maintains the performance of the wet dialyzer before gamma ray sterilization (see Comparative Example 1), and the storage stability is significantly improved. It was confirmed that

[0046]

[Table 2]

[Example 4] A dialysis machine in a semi-wet state was prepared by carrying out the same treatment as in Example 1 except that an aqueous 80% glycerin solution was used in place of the aqueous moisturizer solution used in Example 1. Hot air at 70 ° C to the dialysate side and blood side respectively 5
Aeration was carried out for 20 minutes at a flow rate of 0 L / min to prepare a dry dialyzer in which the water content was reduced to 10% with respect to the total weight of the humectant aqueous solution and the hollow fiber material.

When the performance stability of this dry dialyzer was evaluated, the results shown in Table 3 were obtained. As is clear from Table 3, the dry dialyzer according to the method of the present invention maintains the performance in the wet state before gamma ray sterilization (see Comparative Example 1) even after storage, and the storage stability is significantly improved. It was confirmed.

[0049]

[Table 3]

Claims (8)

[Claims] 1. From a hemodialyzer having a hollow fiber for hemodialysis and having water filled therein, (a) the filling water in the dialyzer is physically removed under the condition that the hollow fiber is not dried. After that, (b) the humectant aqueous solution is passed through the hollow fiber core, and at the time, the humectant aqueous solution is impregnated with the humectant aqueous solution so that the humectant aqueous solution does not exude from the outer wall of the hollow fiber to the outside. Then, (c) physically removing the moisturizer aqueous solution remaining in the hollow fiber core under the condition that the hollow fiber is not dried,
A method for producing a semi-wet hemodialyzer, comprising: 2. The method for producing a semi-wet hemodialyzer according to claim 1, wherein the hemodialysis hollow fiber is a hollow fiber made of cellulose ester. 3. The humectant is glycerin, ethylene glycol, propylene glycol, polyethylene glycol,
The method for producing a semi-wet hemodialyzer according to claim 1 or 2, which is a polyhydric alcohol selected from polypropylene glycol. 4. The humectant aqueous solution remaining in the hollow fiber core portion,
The method for producing a semi-wet hemodialyzer according to any one of claims 1 to 3, wherein the hollow portion of the hollow fiber is removed by aeration with pressurized air. 5. A hemodialyzer having a hollow fiber for hemodialysis and having water filled therein, the hollow fiber bundle is housed in a dialysis container and adhered and fixed to the dialyzer to be assembled. The method for producing a semi-wet hemodialyzer according to any one of claims 1 to 4, characterized in that the core fluid is washed and removed, and then filled with water. 6. A sterilization characterized in that a semi-wet hemodialyzer is produced by the method according to claim 1, and the hemodialyzer is sterilized by gamma irradiation. Method for making a semi-wet hemodialyzer. 7. A semi-wet hemodialyzer is produced by the method according to claim 1, and the hemodialyzer is dried to form at least a part of water contained in the hollow fiber. A method for producing a hemodialyzer in a dry state, characterized in that: 8. A method for producing a hemodialyzer in a dry state by the method according to claim 7, and then sterilizing the hemodialyzer by gamma ray irradiation. Method.