JPH0470932B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning pyrodiene-contaminated membranes.

Membranes used for sterilization of pharmaceutical products not only need to be sterile due to their nature, but also must not contain substances that generate heat in vivo.

In particular, injectable fluids such as ring fluid that are injected into the human body must not only be sterile, but also must not contain substances that generate heat when they enter the body (hereinafter referred to as pyrogienes). Recently, it has been revealed that pyrodiene derived from microorganisms consists of a substance whose main component is polyliposatucaroid with a molecular weight of 10 ⁵ or more.
It has become common to use ultrafiltration membranes with a molecular weight cut-off of ¹⁰⁵ or less to remove pyrodiene from injectable fluids such as ring fluid.

However, since membranes with a molecular weight cut-off of approximately 10 ⁵ have a very fine and complex structure, it has been extremely difficult to completely remove the pyrodiene substances incorporated therein.

Therefore, polyliposaccharoid, which is the main component of pyrodiene, can be thermally decomposed with an alkali,
Adding a surfactant or deoxycholic acid to reduce the molecular weight of polyliposaccharoid, or
Attempts have been made to destroy the exothermic properties of pyrodiene by heating it to temperatures above 250°C.

However, all of these methods require extremely harsh conditions, which not only destroy the exothermic properties of the pyrodiene but also deteriorate the film itself, making it difficult to apply in practice.

For example, in the Kasaoka Symposium (Contribution, Records, and Applications of Horseshoe Crabs to Medicine) 1976, "About the Specificity of Gelation Reactions" (Mitsuru Tamba), treatment with 0.03N NaOH in 95% ethanol at 37°C for about 1 hour
Endotoxin E.coli0113 of Salmonellaminnesta114W strain
It is stated that although the pyrogenic properties of the strain endotoxin can be reduced, the pyrogenic properties of the Salmonella minnesota R595 strain cannot be changed.

The inventors of the present invention have carefully studied the conditions under which the membrane does not deteriorate but all of the pyrogen's exothermic properties are lost in a short period of time. As a result, the inventors determined that the alkali concentration should be 0.01% or more, and the alcohol concentration should be maintained under conditions that stabilized this alkali. After reducing the exothermic properties of all the pyrodiene by treatment with this solution for about 1 hour by bringing it to the concentration required to dissolve it under
By using pyrogen-free water to remove the pyrogen with reduced exothermic properties, a film completely free of pyrogen was obtained, and it was also revealed that the mechanical properties of the film were low.
This led to the present invention.

That is, in the present invention, the membrane is immersed in a mixed solution of alcohol and sodium hydroxide aqueous solution in which the proportion of alcohol is 10 to 90 wt% and the concentration of the sodium hydroxide aqueous solution is 0.01 to 20 wt%, and then immersed in pyrogen-free water. This is a method of cleaning pyrodiene-contaminated membranes by washing with water until alkali can no longer be detected.

The alcohol used in the present invention preferably has a lower surface tension than water (40 dyn/cm or less) and is miscible with water, such as methyl alcohol, ethyl alcohol, propyl alcohol, etc. What you have is good.

The concentration of the aqueous sodium hydroxide solution mixed with these alcohols may be any concentration that can render the pyrodiene inactive against heat generation, and is 0.01wt% to 0.01wt%.
Various 20wt% solutions are used. If the sodium hydroxide concentration is less than 0.01wtu, it is not possible to inactivate all of the pyrodiene, and if it is more than 20wt%, sodium hydroxide is strongly basic, so the membrane members constituting the module, This is not preferable because it significantly alters the quality of the adhesive packing. Preferably it is 0.1-10%.
In addition, the proportion of alcohol mixed with the sodium hydroxide aqueous solution is preferably 10 to 90 wt% of the total, and 10 wt%
% or less, it is not preferable because not only the permeability into the membrane material decreases, but also the bactericidal power as an alcohol aqueous solution decreases. Also, if it is 90wt% or more,
Since the water fraction decreases, the dissolution stability of sodium hydroxide decreases, and it may precipitate when left in the air, which is not preferable.

In the present invention, membranes include vinyl resins such as polyacrylonitrile, polyethylene, polypropylene, vinyl chloride, vinyl fluoride, vinylidene fluoride, and Teflon; heat-resistant resins such as polyamide, polyester, polycarbonate, polyimide, polyamideimide, and polysulfone; These are membranes made from cellulose polymers, such as microfilters such as sterilization filters, ultra-vortex membranes, and reverse osmosis membranes. However, the method of the present invention is particularly suitable for removing pyrodiene contained in membranes with a complex structure, such as those with a skin structure on the surface and an internal support structure, which have a molecular weight cutoff of 10 ⁵ or less. By reducing the molecular weight of the pyrodiene deeply incorporated into the microstructure, it can be easily released from the surface of the porous membrane and rendered inactive due to heat generation.

Generally, these pyrogienes are mainly composed of polyliposatucaroids found in the outer skin of Escherichia coli, etc., and polyliposatucaroids have the property of being easily adsorbed on the membrane surface or fine structure made of polymeric materials.

In the present invention, the membrane is completely impregnated with the above-mentioned alcoholic solution of sodium hydroxide aqueous solution, but by leaving it for about 0.5 hours or more after impregnation at 25°C, for example, the exothermic properties of the pyrodiene contained in the membrane are reduced. do.

The present invention is also advantageous when the polymer constituting the membrane material is a water-repellent polymer that does not get wet with water, in other words, has the property of repelling water and preventing it from penetrating into the membrane.

In the present invention, washing with water refers to washing a membrane impregnated with a solution of alcohol and sodium hydroxide with pyrogen-free water. Pyrogen-free water refers to water that has been filtered through a membrane with a molecular weight cut off of 10 ⁵ or less, and water from which pyrogen has been completely removed (hereinafter referred to as pyrogen-free water).

When washing with water, the outlet of the module on the water side is often contaminated with pyrogen, so care must be taken to ensure that the outlet of the module on the water side is not contaminated with pyrogen.

The washing time with pyrogen-free water should be at least 10 minutes, and it is better to wash vigorously.

In addition, the molecular weight cutoff of the membrane from which you want to remove pyrodiene is
When it is less than ¹⁰⁵ , pyrogen-free water can be obtained from the membrane itself, so water pressure is applied from the opposite side of the membrane from where you want to remove pyrogen.
By pressurizing purified water (which may contain pyrodiene), a membrane is obtained that is completely free of pyrodiene on the opposite water side of the membrane. According to this method, a pyrogen-free module can be easily obtained without preparing any other pyrogen-free module.

More preferably, the membrane should be thoroughly washed with 0.1 cm ² or more of pyrogen-free water per 1 cm ² of the membrane surface.Even if the membrane is washed for a long time, if the amount of washing water is small, the exothermic pyrogen will remain in the module. It turns out.

Example 1 A polyacrylonitrile resin membrane with a molecular weight cut off of 13000 (product name: ACL1011 hollow fiber module manufactured by Asahi Kasei Corporation) was used as the membrane, and as pyrodiene,
Endotoxin E.coli0111B4 and Salmonella
A 100 c.c. aqueous solution containing 100 mg of each of Minnesota R595 was poured into the module through the inlet on the concentration side and the outlet on the water side, and was allowed to penetrate the membrane well.

It was confirmed that the aqueous solution was toxic using the pyrodiene detection reagent Pregel. Next, the endotoxin aqueous solution was drained from the module, a well-mixed solution of 70 parts by weight of ethanol and 30 parts by weight of a 1% NaOH aqueous solution was poured into the module, and the module was covered with a lid.

The module was shaken for 6 hours at 25°C on a shaker.

Thereafter, a water pressure of 1 kg/cm ² was applied from the inlet and outlet of the module, purified water was sent in a total filtration system, and water was discharged from the water outlet to wash the alcohol solution inside the module for 1 hour. Next, after confirming by electrical conductivity that alcohol and NaOH did not come out from the water side outlet, the water side outlet was sterilized by wiping with ethanol and left for one day. After that, when the water on the water side was taken and pyrogenic substances were detected, no pyrogenic substances were detected.

Comparative Example 1 A module contaminated with a pyrogenic substance in the same manner as in Example 1 was added with 95 parts by weight of ethanol, 0.15%
A mixed solution of 5 parts by weight of NaOH aqueous solution and a mixed solution of 5 parts by weight of ethanol and 95 parts by weight of 1% NaOH aqueous solution were prepared and poured into each. Then, after shaking each in a shaker for 6 hours, a water pressure of 1 kg/cm ² was applied from the inlet on the concentration side of this module, and purified water was sent in a total pass-through method, and the water was discharged from the water outlet.
Alcohol and NaOH were washed away. After sterilizing the water outlet by thoroughly wiping it with ethanol, it was left for one day. One day later, water was taken from each liquid side and it was confirmed that there was a pyrogen in both cases.

Example 2 The membrane was a polysulfone resin membrane (product name:
Endotoxin E.coli0111B4 100mg/100 as a pyrogenic substance using SIP1013, molecular weight cutoff: 6000)
Prepare a cc aqueous solution and pour it into the module.
Contaminated the module. After confirming that the solution is clearly toxic using the pyrogenic substance detection reagent pre-gel, remove the endotoxy solution from this module and thoroughly mix 70 parts by weight of ethanol and 30 parts by weight of 10% NaOH aqueous solution in this module. The solution was poured into the container and shaken using a shaker for 6 hours. A water pressure of 1 Kg/cm ² was applied from the inlet on the concentration side of this module, water was drawn out in a total filtration system for 1 hour, and alcohol and NaOH were washed for 1 hour. After confirming that alcohol and NaOH could not be detected using an electrical conductivity meter, the water side outlet was thoroughly wiped with ethanol to make it pyrogen-free, covered with a lid, and left for one week. One week later, water was taken from the water side and it was confirmed that no pyrogenic substances were detected.

Example 3 After removing the alcohol and NaOH solutions in Example 2, pyrogen-free water was added at 1 kg/cm ² from the concentration side inlet of the module, water was removed using a total filtration method, and alcohol and NaOH were removed for 6 hours. Washed with water. After confirming that alcohol and NaOH could not be detected by electrical conductivity, the water side outlet and concentration side inlet were thoroughly wiped with ethanol to make them pyrogen-free, covered with a lid, and left for one week. One week later, water was taken from the water side and the concentration side, and it was confirmed that no pyrogenic substances could be detected.

Comparative Example 2 An experiment was conducted under the same conditions as in Example 3 except that the washing time was 5 minutes, and a pyrogenic substance was detected.

Example 4 Using the same module as in Example 1, various pyrogenes were prepared (1) S.abortusequi (2) S.
typhimurium(3)S.minnesota9700(4)S.
typhosa0901(5)S.entritidis(6)S.marcescens(7)E.
Nine 2.5 μg/ml solutions of E. coli0128B12(8)E.coli055B5(9)E.cli0127B8 were prepared, and the concentration side and permeation side of the module were contaminated with the respective pyrodiene solutions in the same manner as in Example 1. We were able to remove pyrogen from each of them and make them all pyrogen-free.

Claims (1)

[Claims] 1. The membrane is made of a mixed solution of alcohol and sodium hydroxide aqueous solution, the proportion of alcohol is 10 to 90 wt%,
The concentration of the above sodium hydroxide aqueous solution is 0.01~20wt
%, and then washing with pyrogen-free water until alkali can no longer be detected. 2. The method for cleaning a pyrodiene-contaminated membrane according to claim 1, wherein the membrane has a molecular weight cut-off of 10 ⁵ or less.