JPH11178904A - Indicator for plasma sterilization - Google Patents

Abstract

(57) [Abstract] [Object] The present invention aims to determine whether or not sterilized equipment has passed through a sterilization process when sterilizing medical equipment or the like by plasma sterilization, and whether or not sterilization has been effectively performed. The present invention relates to an improvement of a chemical indicator for confirming the change in color tone. The present invention relates to a method for plasma sterilization in which a base material is coated or printed with an ink composed of a dye, a color change aid, a binder (binder), and a solvent for dissolving the same, and the color tone is changed by a plasma sterilization method. It is an indicator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a chemical indicator for confirming whether or not sterilization has been effectively performed by changing the color tone by a low-temperature gas plasma sterilization method.

[0002]

2. Description of the Related Art Conventionally, a high-pressure steam sterilization method or an ethylene oxide gas sterilization method has been used for sterilizing equipment used for surgery or treatment in medical institutions such as hospitals.

[0003] In these sterilization methods using the high-pressure steam sterilization method or the ethylene oxide gas sterilization method, it is determined whether or not the equipment to be sterilized has passed through a sterilization process, or whether or not the sterilization conditions applied to the equipment have been appropriate. It is extremely important to do

[0004] As one of the discriminating means or detecting means, a chemical sterilization indicator whose color tone changes due to sterilization is used, and a dedicated sterilization indicator is used in each sterilization method. There is a need.

[0005]

However, the conventionally used ethylene oxide gas sterilization method can perform sterilization at a relatively low temperature (40 to 60 ° C.), so that plastic equipment and endoscopes which are weak to heat are used. Although it is often used for sterilizing mirrors, etc., in the ethylene oxide gas sterilization method, highly toxic ethylene oxide is easily adsorbed and remains on the sterilized equipment, so the highly toxic ethylene oxide attached to the sterilized equipment is used. There is a drawback that it is necessary to perform the removal.

[0006] In recent years, as a sterilization method which can be replaced with a high-pressure steam sterilization method and an ethylene oxide gas sterilization method, a plasma sterilization method using a oxidizing gas such as hydrogen peroxide or other gas and utilizing sterilizing power by low-temperature gas plasma has been proposed. Became used. Known indicators used in the plasma sterilization method include U.S. Pat.
No. 82684 is the only one described.

The technical content described in the above-mentioned US Pat. No. 5,482,684 relates to an apparatus for monitoring a sterilization step in a low-temperature gas plasma sterilization method using a gas containing peracetic acid and acetic acid as main components. Example 5 in column 14 of the specification of Japanese Patent No. 5482684
Describes an indicator that changes color by the plasma sterilization method.

In the indicator described in the above-mentioned US Pat. No. 5,482,684, bromophenol blue, which is a kind of pH indicator incorporated in the indicator, becomes dark blue by the action of peracetic acid or acetic acid gas used for sterilization. From yellow to pale yellow.

On the other hand, the indicator for plasma sterilization of the invention of the present application uses a specific dye incorporated in the indicator in the sterilization process of the plasma sterilization method using oxidizing hydrogen peroxide or peracetic acid. Since it relates to an indicator for sterilization based on the principle of fading (decoloring) by the oxidizing power of a gas having a property, unlike the known technique described in the aforementioned US Pat. No. 5,482,684, it does not have acidity. The present invention can be widely applied to a plasma sterilization method using a gas such as hydrogen peroxide.

An object of the present invention is to provide an indicator for plasma sterilization which shows clear discoloration (color difference) in the course of plasma sterilization and has storage stability, in particular, less discoloration and fading due to light. It is.

[0011]

SUMMARY OF THE INVENTION The present invention is an indicator for plasma sterilization which comprises a dye, a color change aid and a binder, and changes the color tone by a plasma sterilization method.

[0012]

[Function] Hydrogen peroxide, which is an oxidizing gas, has a strong oxidizing power and has been used as a bleaching agent by utilizing its oxidizing power. However, hydrogen peroxide used for hydrogen peroxide plasma sterilization is used. (Concentration in a sterilizer) is extremely low (about several mg / l), and the bleaching (fading) of an indicator prepared by applying an ink containing various dyes on a substrate was examined. No complete discoloration was found during the sterilization process.

Therefore, an additive (discoloration aid) was added in addition to the dye and the binder, and the combination was changed to produce an indicator as a trial, and a discoloration test was performed by the plasma sterilization method. As a result of the discoloration test, a compound having a mercapto group or a compound having a dithiocarbamyl group and a compound having a mercapto group or a compound having a dithiocarbamyl group are used as additives (discoloration aids). It has been found that the indicator obtained by applying the containing ink on the base material clearly discolors during the plasma sterilization step.

In particular, an ink containing the triphenylmethane-based basic dye or a compound having a mercapto group or a compound having a dithiocarbamyl group and either a carbinol base or a cyanine-based basic dye as a color-change aid is used. The indicator applied on the material has a clear color tone before sterilization, and has little discoloration or fading when exposed to environmental light such as sunlight or fluorescent light, and has practically sufficient storage stability. I found that.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to (a) a triphenylmethane-based basic dye or a carbinol-based or cyanine-based basic dye, (b) a compound having a mercapto group or a compound having a dithiocarbamyl group (discoloration aid). An indicator for plasma sterilization obtained by printing or applying an ink containing a binder (agent) and (c) a binder (binder) as essential components on a substrate.

The dye such as a triphenylmethane-based basic dye or a carbinol base or a cyanine-based basic dye incorporated in the indicator may be a compound having at least a part having a mercapto group or a dithiocarbamyl group in the ink. In some cases, a salt is formed with the discoloration aid, which is a compound having the compound, but the dye containing this salt is discolored by low-temperature gas plasma sterilization and changes colorless or almost colorless.

The speed of discoloration of the indicator due to sterilization and the stability to light are determined with respect to the type and amount of each dye, the amount of the compound having a mercapto group or the compound having a dithiocarbamyl group (discoloration aid). It was recognized that the type and the amount of the binder and the type and the amount of the binder (binder) were also related.

The indicator according to the present invention can be modified with a color tone before and after sterilization by blending another dye in addition to the above essential components.

The dye as a component necessary for preparing the indicator for plasma sterilization according to the present invention is a dye which is decomposed and discolored by an oxidation reaction or the like during the plasma sterilization step, and is a triphenylmethane-based basic dye or a cyanine-based dye. Use a basic dye.

Examples of triphenylmethane-based basic dyes include malachite green, fuchsin (magenta), pararoseaniline, methyl violet, crystal violet, Victoria blue, night blue and the like. Although high in oxalates, salts of other acids can also be used. Also, a carbinol base which does not form a salt with an acid can be used as a suitable dye.

Examples of cyanine-based basic dyes include the following. C. I. Basic Orange 27 C.I. I. Basic Red 12-15, 27, 37 C.I. I. Basic violet 15, 39 C.I. I. Basic Blue 62

In addition to the dye as an essential component, any dye that does not fade by plasma sterilization may be used for the purpose of modifying the color tone of the indicator for plasma sterilization before and after sterilization.

The discoloration aid as an essential component for preparing the indicator for plasma sterilization of the present invention is a compound having a mercapto group (Chemical Formula 1) or a compound having a dithiocarbamyl group (Chemical Formula 2).

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Examples of the compound having a mercapto group (-SH) (discoloration aid) include 2-mercaptobenzthiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 3-mercapto-1,
2,4-triazole, 3-mercapto-4-methyl-
4H-1,2,4-triazole, 2-mercaptothiazoline, 5-methyl-1,3,4-thiadiazole-2
-Thiol, 1-phenyl-5-mercapto-1H-tetrazole, 2-amino-5-mercapto-1,3,4
-Thiadiazole, 2,5-dimercapto-1,3,4
-Thiadiazole, 5-mercapto-1-methyltetrazole, mercaptosuccinic acid and the like.

The compound having a dithiocarbamyl group (color-change aid) includes tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, bis (pentamethylene) thiuram disulfide, diethyl Examples thereof include 2-benzothiazolyl dithiocarbamate and the like.

As the binder (binder) as an essential component for preparing the indicator for plasma sterilization of the present invention, the binder is well soluble in the solvent used for dissolving the pigment and the discoloration aid, which are components of the ink. At the same time, it is necessary to select a compound having good compatibility with the above-mentioned coloring matter and discoloration aid in order to improve the color tone of the indicator and the long-term storage stability.

Examples of the main binder that can be used as a binder (binder) include cellulose derivatives such as cellulose acetate, cellulose acetate butyrate, cellulose nitrate, methylcellulose, ethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose; Or completely saponified compounds), polyvinyl acetate, polyvinyl butyral, polyvinyl pyrrolidone, vinyl methyl ether and other vinyl polymers.

With respect to the amounts of the pigment, discoloration aid, binder (binder) and solvent as essential components to be incorporated into the ink for preparing the indicator for plasma sterilization of the present invention, the types and properties of each component Although it cannot be said unconditionally because it differs depending on the following, the following degree. Dye 0.1 to 2 parts Discoloration aid 0.3 to 10 parts Binder 6 to 20 parts Solvent 70 to 90 parts

As the coloring matter, 0.16 parts of a carbinol base of fuchsin, which is a basic triphenylmethane coloring matter, and in Example 1, 2-amino-5-mercapto-1,3,4-thiadiazole. 5 parts, Example 2 1.5 parts tetraethylthiuram disulfide, Example 3
In this example, 1.5 parts of diethyldithiocarbamate-2-benzothiazolyl, 12 parts of ethyl cellulose (Ethocel No. 4 manufactured by Dow Chemical Company) as a binder (binder), and a mixture (1: 1) of methyl ethyl ketone and isopropanol (1: 1) of about 86.3 as a solvent. To create ink using the
Each was hand-coated with a 0.25 m / m wire bar on a substrate of polyethylene synthetic paper (Tyvek, manufactured by DuPont) to produce the indicators for plasma sterilization of Examples 1 to 3.

Each of these indicators had a pink-red color, but was sterilized under standard conditions using a plasma sterilizer (manufactured by Johnson & Johnson Medical, USA) (STERRAD100 is a plasma sterilizer using hydrogen peroxide). As a result, the dye completely faded and turned colorless.

Further, when these indicators were sterilized under standard conditions using a plasma sterilizer (PLAZLYTE using a mixture of hydrogen peroxide, peracetic acid and acetic acid) manufactured by Abtok, USA,
The color changed to colorless.

In order to compare with the above Examples 1-3, among the components of the ink used in the above Examples, products which did not contain a discoloration aid (Comparative Examples 1 to 3) were prepared and hand-coated on Tyvek. An indicator for plasma sterilization was prepared.

This was sterilized under the same conditions as in Examples 1 to 3 above using a plasma sterilizer manufactured by Johnson & Johnson Medical Co., Ltd. and a plasma sterilizer manufactured by Abtok, USA. The dye was incompletely discolored and reddish.

The samples of Examples 1 to 3 and Comparative Examples 1 to
When the sample of No. 3 was exposed to direct sunlight for 2 hours in advance, the samples of Examples 1 to 3 only slightly darkened the color tone, but the samples of Comparative Examples 1 to 3 showed considerably fading.

When these samples exposed to sunlight were sterilized by the above two types of plasma sterilizers under the same sterilization conditions as above, the samples of Examples 1 to 3 were completely discolored and became colorless. However, the sample of Comparative Example 1 did not completely fade, and slightly remained reddish.

As the dye, a basic cyanine dye is used.
An ink was prepared in the same manner as in Examples 1 to 3 except that 0.16 part of Basic Red 12 was used, and hand-painted with a 0.25 m / m wire bar on Tyvek manufactured by DuPont, USA, to prepare Examples 4 to 6. An indicator for plasma sterilization was prepared.

Although the indicators of Examples 4 to 6 all showed a deep pink color, as in Examples 1 to 3, a plasma sterilizer manufactured by Johnson & Johnson Medical, USA and a plasma sterilizer manufactured by Abtok, USA were used. All were colorless when sterilized under standard conditions.

Examples 4 to 6 except that no discoloration aid was added.
An ink was prepared with the same composition as described above, and the ink was hand-coated on Tyvek to prepare indicators for plasma sterilization of Comparative Examples 4 to 6. This was sterilized with a plasma sterilizer manufactured by Johnson & Johnson Medical, USA under the same conditions as in Examples 4 to 6, and almost no fading occurred.

When this sample was sterilized with a sterilizer manufactured by Abtok, USA under the same conditions as in Examples 4 to 6, the sample was almost completely faded and became colorless. However, this sample was inferior in light stability as compared with the samples of Examples 4 to 6 as described below.

The samples of Examples 4 to 6 and Comparative Examples 4 to 6 were previously exposed to direct sunlight for 2 hours.
The sample of Comparative Examples 4 to 6 showed significant fading, while the sample of No. 6 showed a degree of deep pink discoloration.

Further, as a dye, pararoseaniline hydrochloride 0.18 which is a triphenylmethane-based basic dye is used.
Parts, 0.5 part of 3-mercapto-1,2,4-triazole as a discoloration aid, 10.0 parts of polyvinyl alcohol (completely saponified) as a binder, and about 89 water as a solvent
The ink was prepared by using the above-mentioned parts, and the ink was hand-coated with a 0.25 m / m wire bar on a base material of a polypropylene synthetic paper (Yupo manufactured by Oji Paper Co., Ltd.) to prepare an indicator for plasma sterilization of Example 7.

Although the indicator of Example 7 was red, the indicator was red in the same manner as in Examples 1 to 6 by STERA of Johnson & Johnson Medical, USA.
When sterilized under standard conditions with D100 and PLAZLYTE manufactured by Abtok, USA, it completely faded and became colorless.

An ink was prepared with the same composition as in Example 7 except that no discoloration aid was added, and the ink was manually applied to the synthetic paper YUPO.
An indicator for plasma sterilization of Comparative Example 7 was produced.
This was applied to the plasma sterilizer STER in the same manner as in Example 7.
When sterilized with RAD100 and PLAZLYTE, the color hardly faded and remained red. The samples of Example 7 and Comparative Example 7 were exposed to direct sunlight for 2 hours, but none of the discoloration was significant.

0.1 parts of a carbinol base of Victoria Blue, which is a triphenylmethane dye, 3 parts of tetraethylthiuram disulfide as a discoloration aid, and ethyl cellulose (Ethcel No. 4 manufactured by Dow Chemical Company) as a binder (binder). ) 12 parts, a mixture of methyl ethyl ketone and isopropanol (1: 1) 8 as a solvent
An ink was prepared using 4.9 parts and hand-coated with a 0.25 m / m wire bar on a substrate of polyethylene synthetic paper (Tyvek, manufactured by DuPont) and cellulose-based sterilized paper. An indicator for plasma sterilization was made.

Each of these indicators had a blue color tone, but was manufactured by Abtok's plasma sterilizer PL.
When subjected to sterilization under standard conditions in AZLYTE, all of them completely faded and became colorless.

The Tyvek coated product was treated with a plasma sterilizer STE manufactured by Johnson & Johnson Medical Co., Ltd.
When sterilized with RRAD100, it completely faded and became colorless. In addition, since sterilization of the cellulosic material was prohibited in STERRAD100, the sterilization test of the hand-painted product on the sterilized paper was not performed.

An ink was prepared in the same manner as in Example 8 except that no discoloration aid was blended, and the ink was hand-coated on a Tyvek or sterile paper substrate to prepare an indicator for plasma sterilization of Comparative Example 8. did. When this was sterilized with a sterilizer PLAZLYTE manufactured by Abtok Co., USA, the color was only slightly faded and blue.

Further, a hand-painted sample on Tyvek was prepared using a sterilizer STE manufactured by Johnson & Johnson Medical, USA.
When sterilized by RRAD100, even in this case, the color was slightly faded and blue. When the indicators of Example 8 and Comparative Example 8 were exposed to direct sunlight for 2 hours, the samples of Example 8 showed little fading, but Comparative Example 8
The sample No. had a high degree of fading.

In Example 9, a triphenylmethane-based basic dye, pararoseaniline hydrochloride 0.1%, was used.
18 parts, and phthalocyanine green 0.50 as a fast colorant that does not fade during plasma sterilization
Part, Kayaset Yellow 476 (Nippon Kayaku Co., Ltd.) 0.1
0 parts were used.

In Example 10, the dye was 0.26 parts of Basic Red 12 which is a basic cyanine dye,
In addition, 0.50 part of phthalocyanine green and 0.10 part of Kayaset Yellow 476 (manufactured by Nippon Kayaku Co., Ltd.) were used as dyes having high fastness that would not fade during plasma sterilization.

Examples 9 and 10 were common to each other. 0.80 part of tetraethylthiuram disulfide was used as a discoloration aid, 12 parts of ethylcellulose (Ethocel No. 4 manufactured by Dow Chemical Company) was used as a binder (binder), and a solvent was used as a solvent. Using about 85.4 parts of ethanol, these were made into an ink by a ball mill, and each was placed on a base of polyethylene synthetic paper (Tyvek, manufactured by DuPont) for 0.25 m.
/ M was manually applied using a / m wire bar to prepare the indicators for plasma sterilization of Examples 9 and 10.

The color tone of the indicators of Examples 9 and 10 was brown and slightly brownish red, respectively, and they were converted to a plasma sterilizer STERRAD10 manufactured by Johnson & Johnson Medical, USA.
When the sample was sterilized under standard conditions at 0, the pigments Pararoseaniline and Basic Red 12 contained in each of the samples completely discolored and turned green.

An ink was prepared in the same manner as in Examples 9 and 10, except that no discoloration aid was added, and hand-coated on Tyvek to prepare indicators for plasma sterilization of Comparative Examples 9 and 10. The color tones of the indicators of Comparative Example 9 and Comparative Example 10 were Example 9 and Example 1, respectively.
It was almost the same as the color tone of the indicator of 0. These were sterilized in the plasma sterilizer STERRAD100 under the same conditions as in Examples 9 and 10, and none of them was discolored.

Examples 9 and 10 and Comparative Example 9
When the indicator of Comparative Example 10 was exposed to direct sunlight for 2 hours, the indicator of Example 9 slightly darkened but no fading was observed, but the indicator of Comparative Example 9 faded in addition to darkening. There was a tendency to. In each of the indicators of Example 10 and Comparative Example 10, some fading was observed, but in the case of Example 10, the degree of fading was smaller than that of Comparative Example 6.

[0055]

As described above, the indicator for plasma sterilization produced by applying the present invention has the following effects. First, the use of a material coated or printed on the surface of a sterile packaging material made of sterile paper or other materials makes it possible to determine whether or not an object to be sterilized has passed through a sterilization step by color.

Second, if the printed matter on a card or the like is sterilized together with the object to be sterilized, it is possible to detect from the change in color tone whether or not the sterilization conditions applied to the object after sterilization are appropriate.

Third, since there is little discoloration or deterioration (deterioration in discoloration during sterilization) due to environmental light (sunlight, fluorescent light, etc.), the indicator is easy to handle and store.

Claims (4)

[Claims] 1. A dye, a discoloration aid and a binder (binder)
An indicator for plasma sterilization, characterized in that the color tone is changed by a plasma sterilization method. 2. The indicator for plasma sterilization according to claim 1, wherein the dye is a triphenylmethane dye or a cyanine dye. 3. A dye according to claim 1, wherein the dye is one or more of a triphenylmethane dye and a cyanine dye, and at least one of compounds having a mercapto group as a color change aid. Or the indicator for plasma sterilization according to 2. 4. The indicator for plasma sterilization according to claim 1, wherein at least one of compounds having a dithiocarbamyl group is used as a discoloration aid.