sterilization components

Abstract

To provide a composition for sterilization having low toxicity and enhanced durability of sterilizing effect.SOLUTION: A composition for sterilization includes lactic acid and ethanol, where the mass ratio of lactic acid to ethanol is within a range of 55:45 to 80:20.

Description

Technical Field

[0001] The present invention relates to a composition for sterilization. More specifically, the present invention relates to a composition for sterilization containing lactic acid and ethanol.

Background Art

[0002] Sterilization is a particularly interesting technology in the food industry, restaurants, the catering industry, beauty salons, hospitals, clinics, nursing homes, accommodation facilities, etc.

[0003] In the prior art, in order to perform sterilization, chlorine-based disinfectants such as sodium hypochlorite and benzalkonium chloride, and disinfectants such as cresol soap and povidone iodine have been used. However, these disinfectants have high toxicity and can hardly be used for general sterilization in daily life and for sterilization of surfaces that users may come into contact with. In addition, the use of sodium hypochlorite is also restricted in that it has a corrosive effect on metals.

[0004] Also, it is known that a high-concentration (for example, 70% by volume or more) ethanol solution can be used for sterilization. However, since ethanol is flammable, care must be taken with respect to fire, electric sparks, etc. In addition, due to the high volatility of ethanol, there is a problem that the sterilization effect does not persist.

[0005] Furthermore, disinfecting compositions containing ethanol and organic acids have been developed (see Patent Documents 1 to 4). However, all of these compositions contain ethanol as the main sterilizing component.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

[0007] The object of the present invention is to provide a disinfectant composition that is low in toxicity and has a long-lasting disinfecting effect. [Means for solving the problem]

[0008] A first embodiment of the present invention is a disinfectant composition comprising lactic acid and ethanol, wherein the mass ratio of lactic acid to ethanol is in the range of 55:45 to 80:20. The disinfectant composition may contain 40 to 72% by mass of lactic acid based on the mass of the composition.

[0009] A second embodiment of the present invention is a disinfectant solution comprising the disinfectant composition of the first embodiment and water. The disinfectant solution may contain 10 to 18% by mass of lactic acid based on the mass of the disinfectant solution. [Effects of the Invention]

[0010] The disinfectant composition and disinfectant solution of the present invention, by containing lactic acid and ethanol within the aforementioned mass ratio range, can achieve excellent immediate disinfection and excellent sustained disinfection. Furthermore, since the disinfectant composition and disinfectant solution of the present invention do not contain highly toxic components, they can be used for general disinfection in daily life and for disinfecting surfaces that users may come into contact with. [Modes for carrying out the invention]

[0011] A first embodiment of the present invention is a disinfectant composition comprising lactic acid and ethanol, wherein the mass ratio of lactic acid to ethanol is in the range of 55:45 to 80:20.

[0012] The lactic acid used in this embodiment may be L-lactic acid ((S)-lactic acid), D-lactic acid ((R)-lactic acid), or DL-lactic acid. Preferably, the lactic acid used in this invention is L-lactic acid. Lactic acid can be produced by either fermentation or synthesis. In this invention, it is preferable to use lactic acid produced by fermentation.

[0013] In the disinfectant composition of this embodiment, the mass ratio of lactic acid to ethanol is in the range of 55:45 to 80:20. Furthermore, the disinfectant composition of this embodiment may contain 40 to 72% by mass, preferably 45 to 68% by mass, of lactic acid based on the mass of the composition.

[0014] The disinfectant composition of this embodiment may further contain additives such as fragrances and pH adjusters.

[0015] The disinfectant composition of this embodiment may be in the form of a so-called "concentrate." By taking the form of a concentrate, it is possible to reduce transportation costs, reduce the amount of waste, and / or reduce storage space.

[0016] A second embodiment of the present invention is a disinfectant solution comprising the disinfectant composition of the first embodiment and water.

[0017] In the disinfectant solution of this embodiment, the mass ratio of lactic acid to ethanol is within the range of 55:45 to 80:20, similar to the first embodiment. Furthermore, the disinfectant solution of this embodiment is a solution obtained by diluting the disinfectant composition of the first embodiment with water, and may contain 10 to 18% by mass of lactic acid based on the mass of the disinfectant solution.

[0018] The disinfectant solution of this embodiment can be applied to the object to be disinfected using known means such as spraying, wiping, brushing, or immersion.

[0019] The disinfecting compositions of the first embodiment and the second embodiment target bacteria such as Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, and Lactobacillus (bacilli and cocci).

[0020] The sterilizing composition of the first embodiment and the composition of the second embodiment can achieve both immediate sterilization effectiveness and persistent sterilization effectiveness. As used herein, "immediate sterilization effectiveness" means the performance of being able to complete sterilization within 10 minutes, preferably within 5 minutes, more preferably within 3 minutes, and most preferably within 1 minute after application to the object to be sterilized. As used herein, "persistent sterilization effectiveness" means the performance of being able to maintain sterilization even after 1 hour, preferably after 6 hours, and more preferably after 8 hours from the application to the object to be sterilized. Here, maintaining the sterilization effectiveness means that even if new bacteria adhere after a predetermined period of time, they will be sterilized within 5 minutes.

Examples

[0021] (Example 1 Immediate Sterilization Effectiveness) (Preparation of Test Bacterial Solution) (Bacillus subtilis) Bacillus subtilis (ATCC 11774) pre-cultured from a preserved strain was streaked on an ordinary agar medium plate and cultured in an incubator at 37°C for 24 hours. After culturing, the colonies were stained, and the colonies without confirmed spores were scraped off and suspended thickly in 30 mL of sterilized purified water to obtain a test bacterial solution.

[0022] (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes) Escherichia coli (JCM20375) pre-cultured from a preserved strain was streaked on an ordinary agar medium plate and cultured in an incubator at 37°C for 24 hours. After culturing, the colonies were stained, and the colonies were scraped off and suspended thickly in 30 mL of sterilized purified water to obtain a test bacterial solution.

[0023] Using Staphylococcus aureus (NBRC 13276), Pseudomonas aeruginosa (ATCC 9027), and Listeria monocytogenes (GTC 00149) instead of Escherichia coli, respective test bacterial solutions were obtained.

[0024] (Lactobacillus) Preserved bacteria (Lactobacillus plantarum, AN3-2) were streaked onto GAM agar medium (Shimadzu Diagnostics Corporation) and cultured anaerobically at 37°C for 48 hours using a Gaspack (registered trademark). After culturing, the colonies were scraped off and suspended in 30 mL of sterile physiological saline to obtain the test bacterial suspension.

[0025] (Preparation of disinfectant solution) A stock solution of the disinfectant composition was obtained by mixing 72.64% by mass of 90% lactic acid, 18.16% by mass of 95% ethanol, 0.12% by mass of fragrance (DK-13), and 9.08% by mass of 60% sodium lactate. The obtained stock solution was diluted with water to four times its original volume to obtain a disinfectant solution.

[0026] (Evaluation of immediate disinfection effectiveness) The rapid disinfecting effect of the disinfectant solution was evaluated using the following procedure. 1 mL of the test bacterial solution was added to 10 mL of the sample (disinfectant solution from Example 2) and mixed. After mixing, the mixture was allowed to react for 1 minute, 3 minutes, and 5 minutes.

[0027] For bacteria other than Lactobacillus, 100 μL of the reaction solution was taken and added to 10 mL of SCDLP medium. The medium was incubated at 37°C for 48 hours, and the growth of the bacteria was assessed. For Lactobacillus, 100 μL of the reaction solution was taken and inoculated onto 10 mL of GAM agar medium (Shimadzu Diagnostics Corporation). The medium was incubated anaerobically at 37°C for 48 hours, and the growth of the Lactobacillus was assessed.

[0028] The test was repeated three times, and samples showing growth of the test bacteria were judged as positive. The results (number of positive samples / total number of samples) are shown in Table 1.

[0029] [Table 1]

[0030] The disinfectant solution of Example 1 exhibited excellent rapid disinfection, completing the elimination of Escherichia coli, Pseudomonas aeruginosa, and Listeria monocytogenes within 1 minute, Staphylococcus aureus and Lactobacillus within 3 minutes, and Bacillus subtilis within 5 minutes.

[0031] (Example 2: Sustained disinfection) (Preparation of disinfectant solution) Disinfectant solution A was obtained by diluting the undiluted disinfectant composition of Example 1 with water to four times its original volume. Disinfectant solution B was obtained by diluting the undiluted disinfectant composition of Example 1 with water to three times its original volume.

[0032] (Preparation of the bacterial suspension for testing) (Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes) Each strain of bacteria, pre-cultured from the stored strains, was inoculated onto ordinary agar medium (Shimadzu Diagnostics Corporation) and cultured aerobically at 37°C for 24 hours. After culturing, the colonies of each bacterium were scraped off with a cotton swab and suspended in ordinary broth medium to obtain the test bacterial suspension.

[0033] (Lactobacillus) A strain of Lactobacillus plantarum (AN3-2), pre-cultured from a preserved strain, was inoculated onto GAM agar medium (Shimadzu Diagnostics Corporation) and anaerobically cultured at 37°C for 2 days using a Gaspack (registered trademark). After culturing, bacterial colonies were scraped off with a cotton swab and suspended in GAM broth medium to obtain the test bacterial suspension.

[0034] (Lactic acid cocci) A strain of bacteria (Lactococcus lactis subsp. cremoris, NBRC100676) that had been pre-cultured from a preserved strain was inoculated onto SCD agar medium (Shimadzu Diagnostics Corporation) supplemented with yeast and magnesium, and then cultured anaerobically at 32°C for two days using a Gaspack (registered trademark). After culturing, bacterial colonies were scraped off with a cotton swab and suspended in SCD broth medium to obtain the test bacterial suspension.

[0035] (Evaluation of disinfection duration: 8 hours) A commercially available P-tile (30cm x 30cm) was divided into 5cm square sections. A spot for applying the test bacterial solution and disinfectant solution was made in the center of each section. The aforementioned P-tile was placed inside a safety cabinet and sterilized by ultraviolet light for 15 minutes.

[0036] 100 μL of the disinfectant solution from Example 1 was applied to the center spot of each section and left for 8 hours. After 8 hours, 10 μL of the test bacterial solution was applied to the center spot of each section and left for 15 minutes. Then, each section of the P-tile was wiped four times with a cotton swab to collect the bacteria. The cotton swabs used for collection were placed in a test tube containing 10 mL of ordinary broth and stirred.

[0037] For Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Listeria monocytogenes, 100 μL of liquid from a test tube was inoculated onto ordinary agar medium and cultured at 37°C to observe the presence or absence of bacterial colony formation. For Lactobacillus, 100 μL of liquid from a test tube was inoculated onto GAM agar medium (Shimadzu Diagnostics Corporation) and cultured anaerobically at 37°C for two days using a Gaspack (registered trademark) to observe the presence or absence of bacterial colony formation. Furthermore, for Lactococcus, 100 μL of liquid from a test tube was inoculated onto SCD agar medium (Shimadzu Diagnostics Corporation) supplemented with yeast and magnesium and cultured anaerobically at 32°C for two days using a Gaspack (registered trademark) to observe the presence or absence of bacterial colony formation. The results are shown in Table 2. In the table, "-" indicates no colony formation, "+" indicates a small number of colonies were formed, and "++" indicates a large number of colonies were formed.

[0038] [Table 2]

[0039] (Evaluation of disinfection duration: 6 hours) For Escherichia coli and Staphylococcus aureus, the duration of disinfection was evaluated by repeating the above procedure, except that the standing time after application of the disinfectant solution was changed to 6 hours. The results are shown in Table 3. In the table, "-" indicates that no colonies were formed, and "+" indicates that a small number of colonies were formed.

[0040] [Table 3]

[0041] The results in Tables 2 and 3 show that the disinfectant solution of the present invention exhibits sustained disinfection against many bacteria. Specifically, disinfectant solution A showed excellent disinfection against Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, and Lactobacillus even after 6 hours. In particular, the results in Table 2 show that disinfectant solution A showed excellent disinfection against Pseudomonas aeruginosa, Listeria monocytogenes, Lactobacillus, and Lactobacillus even after 8 hours.

[0042] Furthermore, it was found that disinfectant solution B, which is at a higher concentration than disinfectant solution A, exhibits superior disinfecting activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, Lactobacillus, and Lactococcus even after 6 hours. In addition, it was found that disinfectant solution B exhibits superior disinfecting activity against Pseudomonas aeruginosa, Listeria monocytogenes, Lactobacillus, and Lactococcus even after 8 hours.

Claims

1. A disinfectant composition comprising lactic acid, ethanol, and sodium lactate, characterized in that the mass ratio of lactic acid to ethanol is in the range of 55:45 to 80:

20.

2. The disinfectant composition according to claim 1, characterized by containing 40 to 72% by mass of lactic acid based on the aforementioned disinfectant composition.

3. A disinfectant solution characterized by comprising the disinfectant composition described in claim 1 and water.

4. The disinfectant solution according to claim 3, characterized in that it contains 10 to 18% by mass of lactic acid based on the aforementioned disinfectant solution.

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