JPS60132566A - Production of medical hollow yarn mambrane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for producing a medical hollow fiber membrane.

Porous hollow fiber membranes made of high molecular weight polymers have selective permeation performance, and are used in a variety of applications by taking advantage of this property.

In the production of hollow fiber membranes, there has been a remarkable advance in the use of raw material composition, hollow fiber membrane formation methods, post-treatment methods, etc., and in particular, hollow fiber membranes for artificial dialysis are being applied to the kidneys. Coupled with the large number of sick people, production continues to increase.

On the other hand, hollow fiber membranes intended for the medical field must be given sufficient consideration in terms of health and safety from manufacture to delivery to users.

Specially used as a cleaning agent in hollow fiber membrane manufacturing methods in which a polymer compound is dissolved in a solvent to form a spinning stock solution, this spinning stock solution is extruded together with a core solution through a spinning nozzle, solidified, and then washed to remove the solvent. In some cases, chemicals or water containing impurities are used, but in these cases, these chemicals and impurities remain in the hollow fiber membrane, making it extremely unsuitable for use as a medical hollow fiber membrane. Furthermore, using water containing bacteria is also undesirable as it can cause bacteria to adhere to the hollow fiber membrane.Bacteria are usually present everywhere, and a slight lapse of care can easily interfere with the hollow fiber membrane manufacturing process. The average clonic time of bacteria varies depending on the type, but it ranges from several tens of minutes to several hours, which means that once contaminated, bacteria can easily multiply.

Although the manufacturing of medical devices is normally carried out in clean rooms, it is still difficult to be optimistic.

Typically, medical hollow fibers are made into modules and undergo a sterilization process before being delivered to the user, increasing safety. If the hollow fibers contain bacteria before the module is created, viable bacteria can be eliminated in the sterilization process, but there is a risk that they may still contain, for example, pyrogienes (pyrogens).

The inventor of the present invention discovered the present invention as a result of intensive research into methods for obtaining hollow fiber membranes for medical use, which are not currently available.

That is, the present invention provides a medical hollow fiber membrane in which a polymer compound is dissolved in a solvent to form a spinning dope, and this spinning dope is extruded from a spinning nozzle together with a core liquid, and after the solidity is set, the solvent is removed from the spinning dope by washing. The manufacturing method is characterized in that sterile water is used as the washing water.

The sterile water used in the present invention is water that has been tested and passed by the membrane filter method of the sterility test method of the Japanese Pharmacopoeia.

The polymer compounds used in the present invention are not particularly limited, and include cellulose esters such as cellulose diacetate and cellulose triacetate; cuprammonium cellulose; polyacrylonitrile; polymethyl methacrylate; polyethylene; and vinyl acetate copolymer. ; holivinyl alcohol; polypropylene, etc. can be mentioned.

These polymer compounds are dissolved in a suitable solvent to prepare a spinning stock solution. Then, this spinning dope is spun out from an annular spinning hole, passed through the air as required, and then solidified. The coagulated hollow fiber is then washed to remove the solvent and produce a medical hollow fiber membrane. The important point in the present invention is that by employing such a method of using sterile water as washing water during such washing, a hollow fiber membrane containing no bacteria could be produced. This washing step may be carried out in a single bath or in a bath divided into multiple stages, but preferably a multi-stage divided method (several stages to several stages) is preferred because it increases the cleaning efficiency. In this multistage division, fresh sterile water flows down into each independent bath to treat the hollow fiber membranes. In addition, it is preferable to provide an ultraviolet sterilizing lamp in the cleaning process in order to prevent the proliferation of viable bacteria that may have been contaminated. Such washing water is caused to flow down in the direction opposite to the direction in which the hollow fiber membrane runs.

In this way, when manufacturing hollow fiber membranes for medical use, by using sterile water as the washing water, hollow fiber membranes with sufficient consideration given to the safety and hygiene aspects of sterile conditions can be created, which can greatly contribute to the medical field. .

Examples of the present invention will be described below, but the present invention is not limited to these examples.

Examples 1 to 3 and Comparative Examples 1 to 2 30 parts by weight of cellulose acetate, 49 parts by weight of dimethylformamide, and 21 parts by weight of polyethylene glycol 200 were stirred and dissolved at 85° C. for 2 hours to prepare a spinning stock solution. This spinning stock solution was left standing at 85° C. for 2 hours to defoam. Spinning was carried out using an annular orifice nozzle. On the other hand, fluidized rough-in was supplied as a core liquid. The hollow stock solution that came out of the annular orifice was allowed to travel 15 cm in the air, and then introduced into a coagulation bath where it was coagulated and then washed with water. This cleaning was carried out in the following three ways by adjusting sterile water each time and flowing it down in the direction opposite to the direction of travel of the hollow fiber membrane.

After that, it was wound into a bobbin shape.

Example 1: The canal of the cleaning process was divided into three sections and sterile water was introduced at the end of each section.

Example 2: The canals of each of the three stages of the multi-stage canal were made independent, and sterile water was introduced into the rearmost part of each canal.

Example 3: Same as Example 2, but each canal was further irradiated with an ultraviolet germicidal lamp.

For comparison, we also considered an example in which sterile water was used instead of sterile water.

Comparative Example 1: Same as Example 1, but ion-exchanged water was used instead of bacterial water.

Comparative Example 2: Same as Example 2, but ion-exchanged water was used instead of CalF bacteria water.

The results of the above Examples and Comparative Examples performed over time are summarized in Table 1.

(7i, bottom margin Table 1 [Notes] 1) For bacteria in ice, 1 ml of general bacteria
Coliform bacteria is] 00m7! Number of viable bacteria per hollow fiber membrane 2) The bacteria retained in a hollow fiber membrane is measured by extracting bacteria from a certain amount of the hollow fiber membrane into sterile water.Based on the above results, sterile water is used as washing water when manufacturing medical hollow fiber membranes. It can be seen that a hollow fiber membrane suitable for medical use without any retention state can be produced.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Claims] 1. Dissolving a polymer compound in a solvent to obtain a spinning stock solution;
A method for producing a medical hollow fiber membrane in which the spinning dope is extruded together with a core liquid from a spinning nozzle, coagulated, and then washed to remove the solvent of the spinning dope, wherein sterile water is used as the washing water. Method for manufacturing hollow fiber membranes. 2. The manufacturing method according to claim 1, wherein the washing step is divided into multiple stages and fresh bacterial water is introduced into each stage. 3. The manufacturing method according to claims 1 and 2, wherein each step of the cleaning process is carried out by irradiating an ultraviolet germicidal lamp.