JPH0446589B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for sterilizing artificial kidneys, plasma separation processing devices, and other body fluid processing devices. (Prior art and its problems) Body fluid processing devices such as artificial kidneys, plasma separation processing devices, artificial lungs, and artificial livers house a large number of hollow fiber membranes in a casing, and both ends of the hollow fiber membranes are covered with urethane. It has a structure in which it is fixed with fixing members such as. Conventionally, when sterilizing such body fluid processing equipment, a dry hollow fiber membrane was built into the casing, and the body fluid inlet/outlet and the dialysate inlet/outlet of the casing were left open and high-pressure steam sterilization was performed directly. It was on. However, since water has a high heat of evaporation, the membrane receives rapid heat from the water vapor and absorbs moisture, resulting in shrinkage of the threads during the drying process after sterilization, caving in of the supporting member, cracks, etc., and a significant decline in membrane function. In some cases, the body fluid treatment equipment itself was damaged. For this reason, for example, JP-A No. 53-84394 and JP-A No. 53-84394,
There is also a known method, as proposed in No. 84395, of filling a casing containing a hollow fiber membrane with physiological saline, distilled water, etc. that is harmless to living organisms, sealing the opening, and then sterilizing it with high-pressure steam. There is. This method has solved the problem of reduced membrane function to some extent, but the problem is that the filling liquid expands and breaks during sterilization, so a buffer member (expandable stopper, liquid-filled bag, etc.) is used to release the liquid. This required a reduction in the efficiency of the manufacturing process and caused an increase in costs. The present invention was proposed to solve the problems of the prior art. (Means for Solving the Problems) When the present invention sterilizes an apparatus in which a body fluid treatment member such as a hollow fiber membrane or an adsorbent is housed in a casing, the body fluid treatment member is sterilized at a concentration of 70v/v% to
The casing is wetted with 95 v/v % ethyl alcohol or isopropyl alcohol, and the inside of the casing is kept under reduced pressure and subjected to high temperature heat treatment. Specifically, the body fluid processing device in the present invention includes an artificial kidney, a plasma separation processing device, an artificial lung, an artificial liver, and the like. The body fluid treatment members housed in the casing include hollow fiber membranes and adsorbents, and the hollow fiber membranes used include cellulose, polyvinyl alcohol, polyester, polysulfone, polymethyl methacrylate, and polyacrylonitrile. There are no restrictions on the material used. In the case of hollow fiber membranes, the bundle is housed in a casing, and both ends are fixed by support members such as urethane resin. Further, one end is provided with a body fluid inlet, and the other end is provided with a body fluid outlet, and the casing is provided with, for example, a dialysate inlet/outlet, a drainage outlet, and the like. In the present invention, the concentration of ethyl alcohol or isopropyl alcohol is 70v/v% to 95v/v%.
The reason for limiting this is that these alcohols have low boiling points, so if the alcohol content is 95v/v% or more, it will evaporate at low temperatures and cannot be sterilized sufficiently.
Further, if the amount is less than 70v/v%, the heat of evaporation becomes greater than the effect of water, and the film tends to deteriorate. Therefore, sterilization is possible without deterioration of membrane function.
A range of 70v/v% to 95v/v% is preferred. In order to wet the body fluid treatment member with the aqueous solution of the low heat of vaporization organic substance, the aqueous solution is usually injected into the body fluid treatment member such as a hollow fiber membrane through the body fluid inlet. The injection amount is set to be enough to wet the body fluid treatment member, for example, 5 to 100 ml. The injection method may be to inject into the outside of the hollow fiber membrane, that is, into the casing, or it may be a method that covers the entire housing, hollow fibers, and urethane (fixed part of the membrane). Further, in the present invention, the air present inside the casing and the air present within the body fluid treatment member are vacuum-suctioned from the body fluid inlet and the casing opening, and the interior is maintained at a reduced pressure of, for example, 30 mmHg or less.
This prevents thermal expansion of air during high-pressure steam sterilization. Note that the body fluid inlet and the opening of the casing are sealed with a plug incorporating an elastic ball such as silicone rubber, and injection of the aqueous solution and vacuum suction are performed by inserting a syringe needle into the plug. Good. In performing high-pressure steam sterilization according to the present invention, a body fluid treatment device into which an aqueous solution of ethyl alcohol or isopropyl alcohol of the above concentration is injected and whose interior is depressurized is enclosed in a packaging container (for example, made of polypropylene) having a vent. Usually 100~130℃
Heat treatment in high pressure steam for 5 to 30 minutes. After that, the temperature is returned to room temperature, the inside of the body fluid treatment device is returned to normal pressure by opening the stopper through the bag, and the aqueous solution of ethyl alcohol or isopropyl alcohol remaining inside the body fluid treatment device and the hollow fiber membrane is vacuum-dried. and remove it. (Example) As shown in Figure 1, the blood inlet 1, blood outlet 2, dialysate inlet 3, and dialysate outlet 4 of a hollow fiber artificial kidney (cellulose-based hollow fiber membrane) are connected to the second
It was sealed with a stopper 6 incorporating a silicone rubber ball 5 as shown in the figure. Thereafter, 70%, 80%, and 90% aqueous ethyl alcohol solutions were injected into the hollow fiber membrane using a syringe through the blood inlet 1 to moisten the hollow fiber membrane. Furthermore, the heat of vaporization of ethyl alcohol is 200 cal/g.
(Water is 540 cal/g). Next, needles 7, 7 connected to a vacuum pump are inserted into the blood inlet 1 and the dialysate inlet 3, and vacuum suction is applied from both the hollow fiber side and the casing side, so that the inside of the artificial kidney is heated to about 30 mmHg. A vacuum was maintained. Thereafter, the artificial kidney is
Heat treatment was performed in high pressure steam under the conditions shown in the table. The number of viable bacteria at each ethyl alcohol concentration was measured, a survival curve was created, and the D value (Decimal reduction
value). This is shown in FIGS. 3 to 5. Furthermore, Figure 3 is based on Table 1, Figure 4 is based on Table 2, and Figure 4 is based on Table 5.
The figure corresponds to Table 3. As shown in the same example, it can be seen that sufficient sterilization effect can be obtained even in a low temperature range by performing high temperature heat sterilization in a state wetted with an aqueous ethyl alcohol solution. Further, in this example, when the ethyl alcohol concentration reached 70%, a slight decrease in membrane performance was observed, but there was no problem in practical use, and the membrane performance was maintained at a satisfactory level. Furthermore, no cracks or the like were observed in the casing. (Effects) As seen in the above examples, according to the present invention, when sterilizing a body fluid treatment device by heating at high temperature, the alcohol concentration can be adjusted without reducing the performance of the hollow fiber membrane etc. fixed to the support member. As a result, sterilization can be performed in a shorter time and at lower temperatures than conventional high-pressure steam sterilization. In addition, since sterilization can be performed at low temperatures, there is no need to provide a buffer member at the mouth of the casing to relieve the pressure of the internal filling liquid, which makes it possible to save labor and reduce costs in the manufacturing process. Excellent effects such as these can be obtained.

【table】

【table】

【table】 [Brief explanation of drawings]

FIG. 1 is a schematic diagram of a body fluid treatment device for explaining an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the structure of the mouth sealing plug according to the present invention, and FIGS. 3 to 5 are according to the present invention. 1 is a bacterial survival curve in Example. In the figure, 1 is a blood inlet, 2 is a blood outlet, 3 is a dialysate inlet, 4 is a dialysate outlet, 5 is an elastic ball,
6 is a stopper.

Claims (1)

[Claims] 1. When sterilizing a device in which a body fluid treatment member is housed in a casing, the body fluid treatment member is wetted with ethyl alcohol or isopropyl alcohol with a concentration of 70 v/v% to 95 v/v%, and the inside of the casing is A method for sterilizing a body fluid treatment device, characterized by performing high temperature heat treatment while maintaining the device in a reduced pressure state.