JP7603952B2 - Biofilm remover and biofilm removal method - Google Patents

Description

The present invention relates to a biofilm remover and a biofilm removal method.

A biofilm is a structure formed by microorganisms. When a biofilm is formed, it can cause harm caused by the microorganisms, which can have various effects on the human body. In addition, microbial control agents such as bactericides tend not to be as effective on microbial aggregates that have formed a biofilm, compared to microorganisms that are dispersed and suspended in water systems.

In response to this, techniques have been proposed relating to skin cleansing compositions and the like capable of removing this biofilm (see, for example, Patent Documents 1 to 3).
However, the skin cleansing composition described in Patent Document 1 and the biofilm remover described in Patent Document 3 have problems in that they are relatively irritating to the skin and impose a heavy burden on the human body. On the other hand, the skin cleansing composition described in Patent Document 2 is still not necessarily sufficient in terms of biofilm removal performance.

JP 2010-241740 A JP 2013-124229 A JP 2013-185036 A

The present invention aims to provide a biofilm remover that has excellent biofilm removal performance and imposes a low burden on the human body, as well as a biofilm removal method using the same.

In order to solve the above problems, the present invention provides a biofilm removing agent and a biofilm removing method as described below.
That is, the biofilm remover of the present invention is a biofilm remover consisting of water and potassium fatty acid, wherein the potassium fatty acid contains (A) potassium oleate and (B) at least one selected from the group consisting of potassium laurate and potassium caprate, and the content of the potassium fatty acid is 6% by mass or more and 34% by mass or less, relative to the total amount of the biofilm remover, the content of the pure content of the (A) component is 6% by mass or more and 85% by mass or less, relative to the total amount of the pure content of the (A) component and the (B) component, and the total amount of the pure content of the (A) component and the (B) component is 75% by mass or more, relative to the total amount of the potassium fatty acid.

The biofilm remover of the present invention preferably does not contain any organic solvent.

The biofilm removal method of the present invention is a biofilm removal method using the biofilm remover, and is characterized by comprising the steps of applying the biofilm remover to a workpiece and washing the workpiece to which the biofilm remover has been applied, thereby removing the biofilm.

The present invention provides a biofilm remover that has excellent biofilm removal performance and imposes little burden on the human body, as well as a biofilm removal method using the same.

Hereinafter, embodiments of the biofilm removing agent and biofilm removing method of the present invention will be described.
[Biofilm remover]
First, the biofilm removing agent of the present embodiment will be described.
The biofilm remover of the present embodiment is composed of water and potassium fatty acid, as described below.
The biofilm remover of this embodiment is preferably composed only of water and fatty acid potassium. The biofilm removal performance can be ensured only by the fatty acid potassium. In addition, the biofilm remover of this embodiment does not need to use any biofilm removal components other than the fatty acid potassium.
In addition, in the biofilm removal agent of this embodiment, from the viewpoint of not using unnecessary components, it is preferable that the agent does not contain any components other than the potassium fatty acid (e.g., organic solvents (such as alcohol) and antibacterial agents, etc.).

It is preferable that the biofilm removing agent of the present embodiment consists only of water and potassium fatty acid, and does not substantially contain any other components than these components.
The water used in the biofilm remover of this embodiment is preferably purified water. Examples of purified water include RO (Reverse Osmosis) water, deionized water, and distilled water. In addition, the purified water is more preferably purified water that conforms to the Japanese Pharmacopoeia or the quasi-drug raw material standard.

The fatty acid potassium used in this embodiment must contain (A) potassium oleate and (B) at least one selected from the group consisting of potassium laurate and potassium caprate. The combination of component (A) and component (B) can improve the liquid stability as a biofilm remover, and can also improve foaming and foam retention.

The component (A) used in this embodiment is a potassium salt of oleic acid, a fatty acid that occurs in extremely large amounts in nature, and has been confirmed to be low in burden on the human body.
The potassium oleate used in this embodiment is obtained from oleic acid and a potassium compound (such as potassium hydroxide) as raw materials. Here, the raw material oleic acid usually contains impurities. Most of these impurities are linoleic acid, but other impurities include stearic acid, linolenic acid, palmitic acid, etc.

The component (B) used in this embodiment is a potassium salt of lauric acid or capric acid, which are fatty acids that occur in extremely large amounts in nature, and has been confirmed to be low in burden on the human body.
The potassium laurate used in this embodiment is obtained from raw materials lauric acid and a potassium compound (such as potassium hydroxide). The raw material lauric acid usually contains impurities, although in small amounts. The impurities include capric acid and myristic acid.
The potassium caprate (potassium decanoate) used in this embodiment is obtained from capric acid as a raw material and a potassium compound (potassium hydroxide, etc.). Here, the raw material capric acid usually contains impurities, although in small amounts. These impurities include caprylic acid and lauric acid.

Impurities other than components (A) and (B) include potassium caprylate, potassium myristate, potassium palmitate, potassium stearate, potassium palmitoleate, potassium linoleate, potassium linolenate, potassium arachidate, and potassium behenate.

In this embodiment, the content of the fatty acid potassium must be 6% by mass or more and 34% by mass or less with respect to the total amount of the biofilm remover. If the content of the fatty acid potassium is less than 6% by mass, the foaming and foam retention of the biofilm remover will be insufficient. On the other hand, if the content of the fatty acid potassium is more than 34% by mass, the biofilm remover will become gel-like.
From the viewpoint of improving foaming and foam retention, the content of potassium fatty acid is preferably 7% by mass or more, more preferably 10% by mass or more, and particularly preferably 15% by mass or more, relative to the total amount of the biofilm remover.
From the viewpoint of improving the stability of the liquid state, the content of the fatty acid potassium is preferably 30 mass % or less, and more preferably 25 mass % or less, based on the total amount of the biofilm removing agent.

In this embodiment, the content of the pure content of the (A) component must be 6% by mass or more and 85% by mass or less with respect to the total amount of the pure content of the (A) component and the (B) component. If the content of the pure content of the (A) component is less than 6% by mass, the foaming and foam retention of the biofilm remover will be insufficient. On the other hand, if the content of the pure content of the (A) component is more than 85% by mass, the stability of the liquid state will decrease, and the foaming and foam retention of the biofilm remover will be insufficient.
From the viewpoint of improving foaming and foam retention, the content of the pure content of the (A) component is preferably 10 mass% or more, and more preferably 15 mass% or more, based on the total amount of the pure contents of the (A) component and the (B) component.
From the viewpoint of improving the liquid stability and improving foamability and foam retention, the content of the pure content of the (A) component is preferably 70 mass % or less, more preferably 60 mass % or less, and particularly preferably 50 mass % or less, based on the total amount of the pure contents of the (A) component and the (B) component.

In this embodiment, the total amount of the pure contents of the (A) and (B) components must be 75% by mass or more based on the total amount of fatty acid potassium. If the total amount of the pure contents of the (A) and (B) components is less than 75% by mass, the liquid stability of the biofilm remover becomes insufficient.
From the viewpoint of improving the liquid stability, the total amount of the pure contents of the (A) component and the (B) component is preferably 80 mass% or more, more preferably 85 mass% or more, and particularly preferably 90 mass% or more, based on the total amount of the potassium fatty acid.
From the viewpoint of ease of production from natural materials, the total amount of the pure contents of the (A) component and the (B) component is preferably 98 mass% or less, more preferably 95 mass% or less, and particularly preferably 92 mass% or less, based on the total amount of potassium fatty acid.

The biofilm remover of the present embodiment may contain an additive within a range that does not impair the object of the present invention. The additive may be at least one selected from the group consisting of a pH adjuster and a chelating agent. More specifically, the additive may be at least one selected from the group consisting of citric acid, tartaric acid, lactic acid, malic acid, oxalic acid, malonic acid, fumaric acid, succinic acid, glycolic acid, phytic acid, or salts thereof.
Furthermore, when the above-mentioned additive is used, the biofilm remover of the present embodiment preferably consists of water, potassium fatty acid, and the above-mentioned additive.

The biofilm remover of this embodiment can be produced by mixing water and potassium fatty acid in the above-mentioned specified ratio and stirring.

[Biofilm removal method]
Next, the biofilm removal method of this embodiment will be described.
The biofilm removal method of the present embodiment is a biofilm removal method using the biofilm removing agent of the present embodiment, and is a method including an application step and a removal step, which will be described below.

In the application step, the biofilm removing agent is applied to an object to be treated.
Here, the biofilm removing agent is preferably in a foam form. As a method for converting a liquid biofilm removing agent into a foam biofilm removing agent, a conventionally known method using a whisk or the like can be adopted. Note that the biofilm removing agent may be foamed after being applied to the object to be treated.
The objects to be treated include the human body (hands, arms, face, head, neck, torso, waist, legs, etc.), animals, and objects.
The application method may be any of the conventionally known methods for applying biofilm removers, including (i) a method in which a biofilm remover is extruded from a container, foamed, and applied, and (ii) a method in which the biofilm remover is rubbed with hands and foamed.
The temperature of the biofilm remover is not particularly limited and may be, for example, 15°C or higher and 45°C or lower.
The amount of the biofilm removing agent to be applied is not particularly limited, and may be appropriately determined depending on the area from which the biofilm is to be removed.

In the removal step, the object to be treated is washed to remove the biofilm.
When washing the object to be treated, water is usually used. Examples of water include purified water, saline, and tap water.
From the viewpoint of being an appropriate temperature for humans, the temperature of the water is preferably 15° C. or higher and 40° C. or lower, and more preferably 25° C. or higher and 35° C. or lower.

As described above, the biofilm removal method of this embodiment can remove biofilms using a biofilm remover. Furthermore, since the biofilm remover of this embodiment places less strain on the human body, the biofilm removal method of this embodiment can remove biofilms in a manner that places less strain on the human body.

Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

[Example 1]
78.7 g of purified water was added to the reaction tank, followed by 4.2 g of potassium hydroxide (100% by mass), and the reaction tank was placed in a warm bath at 70°C. While stirring with a stirrer, 7.9 g of oleic acid (manufactured by Tokyo Chemical Industry Co., Ltd., pure content: 87% by mass) and 9.2 g of lauric acid (manufactured by Tokyo Chemical Industry Co., Ltd., pure content: 99% by mass or more) were added and reacted. After that, the mixture was cooled to obtain a biofilm remover (80% by mass of water, 20% by mass of fatty acid potassium).
In the obtained biofilm remover, the content of fatty acid potassium was 20% by mass relative to the total amount of the biofilm remover. The content of the pure content of the (A) component was 41.5% by mass relative to the total amount of the pure content of the (A) component and the (B) component. The total amount of the pure content of the (A) component and the (B) component was 94% by mass relative to the total amount of fatty acid potassium. The content of fatty acid potassium, the content of the pure content of the (A) component, and the total amount of the pure content of the (A) component and the (B) component in Example 1 are shown in Table 1. The fatty acid potassium composition in Example 1 (the blending ratio of each fatty acid potassium to the total amount of fatty acid potassium ) is also shown in Table 1.

[Examples 2 to 11, 13 to 15, Comparative Examples 1 to 13 , and Reference Examples A to C ]
A biofilm remover was obtained in the same manner as in Example 1, except that the content of the fatty acid potassium, the content of the pure content of component (A), and the total amount of the pure content of component (A) and component (B) were as shown in Table 1. Note that in Example 9, potassium caprate was used as component (B), while in Examples 1 to 8 and 10 to 18, potassium laurate was used as component (B).
In addition, a biofilm remover was obtained in the same manner as in Example 1, except that the content of fatty acid potassium, the content of the pure content of component (A), and the total amount of the pure content of components (A) and (B) were as shown in Table 2.
The following fatty acids were used in Examples 2 to 11, 13 to 15, Comparative Examples 1 to 13 , and Reference Examples A to C. The fatty acid potassium compositions in Examples 11, 13 to 15, and Reference Examples A to C are shown in Table 1. The fatty acid potassium compositions in Comparative Examples 1 to 13 are shown in Table 2.
Oleic acid (Tokyo Chemical Industry Co., Ltd., pure content: 87% by mass)
Lauric acid (Tokyo Chemical Industry Co., Ltd., purity: 99% by mass or more)
Capric acid (decanoic acid, Fujifilm Wako Pure Chemical Industries, Ltd., purity: 98% by mass)
Palmitic acid (Tokyo Chemical Industry Co., Ltd., purity: 99% by mass or more)

[Evaluation of Biofilm Remover]
The biofilm remover was evaluated (biofilm removal ability, foaming/foam retention, liquid stability, stability over time, and skin irritation) by the following methods. The results obtained for the examples are shown in Table 1. The results obtained for the comparative examples are shown in Table 2.
(1) Biofilm Removal Ability The biofilm removing agent was used as a sample, and the biofilm removal rate was measured by the following test method. Then, based on the biofilm removal rate, the biofilm removing ability was evaluated according to the following criteria.
A: Biofilm removal rate is 75% or more.
×: The biofilm removal rate is less than 75%.
(Preparation of biofilm)
The passaged slant (OJ-1, ATCC No. BAA-2856) was pre-cultured in TSA (Trypticase soy agar) slant medium at 37 ° C. for 24 hours. Next, the bacteria were scraped off from the TSA slant medium and diluted with TSB (Tryptic Soybean Broth) so that the absorbance at a wavelength of 600 nm was 0.1 to obtain a bacterial solution. Next, the bacterial solution was dispensed into wells (Corning Co., Ltd. cell culture plate 12 well, for cultured cells) in 1 mL portions. Next, the cells were statically cultured at a temperature of 37 ° C. for 24 hours to form a biofilm. In addition, wells cultured without dispensing the bacterial solution were also prepared (the wells were used to calculate the removal rate).
(Biofilm Removal)
The supernatant of the biofilm was removed, and 1 mL of sterile saline was dispensed and removed once (hereinafter referred to as washing). Next, 1 mL of the sample that had been vortexed for a few seconds immediately before was dispensed into each well. Next, the wells were left to stand for 1 minute at room temperature. Next, the test substance was removed, and the wells were washed three times with 1 mL of sterile saline. The same procedure was carried out for each sample, N=3. Note that, instead of the sample, sterile saline was dispensed and measured, and used as a negative control (this well was used to calculate the removal rate).
(Measurement of biofilm removal rate)
0.5 mL of 0.1% by mass crystal violet aqueous solution was dispensed and left to stand for 1 hour. Next, the supernatant was removed, and the wells were washed twice with 1 mL of sterile saline, and then 2 mL of 99.5% by volume ethanol was dispensed. Next, the insolubilized deposits at the bottom of the wells were scraped off with a plastic Corning rod, and the wells were left to stand for 1 hour to extract the crystal violet. Next, the wells were transferred to a new plate, and the absorbance at a wavelength of 570 nm was measured using a plate reader.
The absorbance of the well after contact with the sterile saline (Ac), the absorbance of the well cultured without the bacterial solution (Ab), and the absorbance of the well after contact with the sample (As) were measured. From these measured values, the biofilm removal rate was calculated based on the following formula (F1).

(2) Foaming and foam retention The biofilm remover was used as a sample, and about 0.5 g of the sample was taken on pre-washed hands, and the sample was foamed in the same manner as when washing hands, and the state was observed. Then, foaming and foam retention were evaluated according to the following criteria.
◯: Sufficient foam is produced and foam retention is good.
△: Although the amount of foam is small, foam is generated and it is usable.
×: Not foaming sufficiently.
(3) Liquid stability The state of the biofilm removing agent when it was prepared or the state 24 hours after preparation was visually confirmed. Then, the liquid stability was evaluated according to the following criteria.
Good: No precipitation, liquid and fluid.
Δ: A part of the composition gels, but after 24 hours it becomes liquid and can be used.
×: Fatty acid potassium is precipitated, or the whole or part of the solution gels and does not become liquid even after 24 hours.
(4) Stability over time The biofilm remover was used as a sample, and 2.5 g of the sample was placed in a glass vial, and the appearance of the sample stored in an incubator at 60° C. for 3 days was visually compared with that of the sample stored in an incubator at 1° C. for 3 days. The stability of the liquid state was evaluated according to the following criteria.
◯: The appearance of each sample is the same or there is a slight change in color tone.
Δ: A clear change in color is observed, but the product is still usable.
×: The color tone changed significantly.
(5) Skin irritation About 0.5 g of the biofilm remover was taken as a sample and placed on pre-washed hands, and the sample was lathered in the same manner as when washing hands. After that, the hands were thoroughly rinsed with tap water at about 35°C and wiped dry. Then, the skin irritation was evaluated according to the following criteria.
○: No irritation to the skin is felt within one minute after wiping off the moisture.
×: Skin irritation is felt within 1 minute after wiping off the moisture.

As shown in Tables 1 and 2, the biofilm removers obtained in Examples 1 to 17 were found to be good in all aspects of biofilm removal, foaming and foam retention, liquid stability, stability over time, and skin irritation. This confirmed that biofilm removers containing potassium oleate have excellent biofilm removal performance and are low in burden on the human body.

The biofilm remover of the present invention is useful as a technology for removing biofilms.

Claims (2)

A biofilm remover consisting of only water and fatty acid potassium,
The fatty acid potassium salt contains (A) potassium oleate and (B) at least one selected from the group consisting of potassium laurate and potassium caprate,
The content of the fatty acid potassium is 6% by mass or more and 34% by mass or less with respect to the total amount of the biofilm remover,
The content of the pure content of the component (A) is 6% by mass or more and 70% by mass or less with respect to the total amount of the pure contents of the component (A) and the component (B),
A biofilm remover, characterized in that the total amount of the pure contents of the component (A) and the component (B) is 89 mass% or more based on the total amount of the fatty acid potassium. A method for removing a biofilm using the biofilm remover according to claim 1 ,
Applying the biofilm remover to a treatment object;
A step of washing the object to be treated to which the biofilm remover has been applied to remove the biofilm;
A biofilm removal method comprising: