WO2018103973A1

WO2018103973A1 - Sanitising system

Info

Publication number: WO2018103973A1
Application number: PCT/EP2017/078197
Authority: WO
Inventors: Amitava Pramanik; Priyanka SARKAR; Nimish Harshadrai Shah
Original assignee: Unilever N.V.; Unilever Plc; Conopco, Inc., D/B/A Unilever
Priority date: 2016-12-09
Filing date: 2017-11-03
Publication date: 2018-06-14
Also published as: EP3551741B1; PL3551741T3; BR112019011552B1; ZA201903270B; EP3551741A1; MX2019006653A; BR112019011552A2

Abstract

The present invention relates to a sanitising system, a sanitizing kit and a method of sanitising hands using said system or kit. The sanitising system comprises a first compartment comprising an alkaline aqueous hypochlorite solution containing 0.0010 to 2.0 wt.% of hypochlorite (CIO^-) and a second compartment comprising an acid aqueous foaming liquid, valve means operable to put both the first compartment and the second compartment in communication with an outlet, wherein, upon operation of the valve means, the hypochlorite solution is mixed with the foaming liquid to produce an aqueous hypochlorous acid (HOCI) solution having a pH in the range of 5 to 7, and the HOCI solution is discharged through the outlet to form a sanitising foam.

Description

SANITISING SYSTEM

Field of the invention

The present invention relates to a sanitising system, a sanitizing kit and a method of sanitising hands using said system or kit.

The sanitising system comprises a first compartment comprising an alkaline aqueous hypochlorite solution containing 0.0010 to 2.0 wt.% of hypochlorite (CIO^") and a second compartment comprising an acid aqueous foaming liquid, valve means operable to put both the first compartment and the second compartment in communication with an outlet, wherein, upon operation of the valve means, the hypochlorite solution is mixed with the foaming liquid to produce an aqueous hypochlorous acid (HOCI) solution having a pH in the range of 5 to 7, and the HOCI solution is discharged through the outlet to form a sanitising foam.

The sanitising kit of the present invention comprises a first container comprising an alkaline aqueous hypochlorite solution containing 0.0010 to 2.0 wt.% of hypochlorite and valve means operable to dispense the hypochlorite solution from the first container; a second container comprising an acid aqueous foaming liquid and valve means operable to dispense the foaming liquid from the second container; and instructions for use instructing users to simultaneously or successively operate the valve means of the first and the second container to dispense the hypochlorite solution and the foaming liquid into a hand of a user.

Background of the invention There is an increasing need for affordable, user friendly and effective sanitising formulations. Alcohol is typically used in antimicrobial sanitising formulations and can be used alone or in combination with antimicrobial agents such as triclosan or benzalkonium salts. Alternatively, an antimicrobial agent can be generated in situ by mixing of components in a dispensing system. For example, US 2013/0202484 AA (Tristel PLC) discloses a hand sanitizer that provides the benefits of an antibacterial alcohol hand wash and sanitizer with the sporicidal properties of chlorine dioxide (CIO2). The hand sanitizer comprises:

· a first part comprising a chlorite solution and contained in a first dispenser whereby it will be dispensed as a spray or jet of liquid; and

• a second part comprising an acid solution and contained in a second dispenser whereby it will be dispensed as a second spray or jet of liquid;

• wherein the chlorite and the acid will react to provide chlorine dioxide when the first part is mixed with the second part; and

• wherein a mixture of equal quantities of the first part and the second part

contains at least 15% alcohol by weight; and wherein at least a part of the alcohol comprises 3-methoxy-3-methylbutan-1 -ol (MMB). The chlorine dioxide is generated in situ by mixing an aqueous sodium chlorite solution held in a container with an aqueous solution of one or more acids and surfactant, held in a second container. Repeated use of such a formulation can lead to skin irritation.

US 2010/0036305 AA (Tristel PLC) discloses a dispensing system that generates CIO2 and that comprises two compartments. The first dispenser chamber is filled with a liquid (first part) which comprises deionised water containing a first reagent (sodium chlorite) and foam promoter (cocamidopropyl betaine). The second dispenser chamber is filled with an aqueous acid solution (second part) comprising deionised water containing citric acid, sorbic acid, boric acid, and foam promoter (cocamidopropyl betaine). The solution also comprises a buffer (trisodium phosphate), trisodium citrate, glycerine, benzotriazole, sodium molybdate and sodium nitrate. The first part and the second part are miscible as liquids and as foams to produce CIO2 on exiting the dispensing system. US 2005/0282722 AA (SC Johnson) discloses a two part soap scum and mold/mildew stain removing composition, the composition comprising:

(a) a first part comprising:

• sodium lauryl sulfate; • sodium lauryl ether sulfate;

• sodium hydroxide in an effective amount to provide a pH of about 4.3-4.6;

• and a balance of water; and

(b) a second part comprising:

· sodium hypochlorite in an amount of about 1.5% to about 3.0% by weight;

• about 3 to about 6% by weight of an amine oxide surfactant;

• sodium hydroxide and alkali metal carbonate in effective amounts to provide a pH in said second part of greater than 12;

• and a balance of water;

and wherein upon combination of said first part and said second part, a combined composition is provided having a pH from about 9 to about 1 1 .

Summary of the invention The inventors have developed a sanitizing system that dispenses a composition having high antimicrobial efficacy and yet is safe for the user's skin.

The sanitizing system of the present invention comprises:

• a first compartment comprising an alkaline aqueous hypochlorite solution, said hypochlorite solution containing 0.0010 to 2.0 wt.% of hypochlorite (CIO^") and having a pH in the range of 8 to 13.5;

• a second compartment comprising an acid aqueous foaming liquid, said foaming liquid containing 0.1 to 5.0 wt.% of a foaming agent and having a pH in the range of 2 to 6;

· valve means operable to put both the first compartment and the second

compartment in communication with an outlet;

wherein, upon operation of the valve means, the hypochlorite solution is mixed with the foaming liquid in a ratio of from 0.8:1 to 1 .3:1 respectively to produce an aqueous hypochlorous acid (HOCI) solution having a pH in the range of 5 to 7, and the aqueous hypochlorous acid solution is discharged through the outlet to form a sanitising foam. When the alkaline aqueous hypochlorite solution and the acid aqueous foaming liquid are mixed together an aqueous hypochlorous acid solution having a pH 5-7 is produced and is discharged in the form of a foam. This foam has anti-microbial properties and is very effective as a small quantity (mass) of foam can cover a large surface area. Once the hypochlorous acid solution has formed, the hypochlorous acid starts to decompose. Hence, there is no prolonged exposure of skin to hypochlorous acid.

Another aspect of the present invention relates to a sanitising kit comprising

· a first container comprising an alkaline aqueous hypochlorite solution, said

hypochlorite solution containing 0.0010 to 2.0 wt.% of hypochlorite and having a pH in the range of 8 to 13.5, said first container comprising valve means operable to dispense the hypochlorite solution from the first container;

• a second container comprising an acid aqueous foaming liquid, said foaming liquid containing 0.1 to 5.0 wt.% of a foaming agent and having a pH in the range of 2 to

6, said second container comprising valve means operable to dispense the foaming liquid from the second container foam;

• instructions for use instructing users to simultaneously or successively operate the valve means of the first and the second container to dispense the hypochlorite solution and the foaming liquid into a hand of a user.

By rubbing the hands together, the user can mix the alkaline aqueous hypochlorite solution and the acid aqueous foaming liquid to form sanitising foam in the form of a foamed aqueous hypochlorous acid solution having a pH 5 to 7.

The invention further provides a method of sanitising hands using a sanitising system or a sanitizing kit according to the present invention.

Detailed description of the invention

As used herein the term "comprising" encompasses the terms "consisting essentially of" and "consisting of". Where the term "comprising" is used, the listed steps or options need not be exhaustive. Unless otherwise specified, numerical ranges expressed in the format "from x to y" are understood to include x and y.

In specifying any range of values or amounts, any particular upper value or amount can be associated with any particular lower value or amount.

Except in the examples and comparative experiments, or where otherwise explicitly indicated, all numbers are to be understood as modified by the word "about". All percentages and ratios contained herein are calculated by weight unless otherwise indicated.

The various features of the present invention referred to in individual sections above apply, as appropriate, to other sections mutatis mutandis. Consequently features specified in one section may be combined with features specified in other sections as appropriate. Any section headings are added for convenience only, and are not intended to limit the disclosure in any way.

A first aspect of the present invention relates to a sanitising system comprising:

· a first compartment comprising an alkaline aqueous hypochlorite solution, said hypochlorite solution containing 0.0010 to 2.0 wt.% of hypochlorite (CIO^") and having a pH in the range of 8 to 13.5;

• valve means operable to put both the first compartment and the second

compartment in communication with an outlet;

wherein, upon operation of the valve means, the hypochlorite solution is mixed with the foaming liquid in a ratio of from 0.8:1 to 1 .3:1 respectively to produce an aqueous hypochlorous acid (HOCI) solution having a pH in the range of 5 to 7, and the aqueous hypochlorous acid solution is discharged through the outlet to form a sanitising foam. The term "hypochlorite" as used herein, unless indicated otherwise, refers to a hypochlorite anion with chemical formula CIO^".

The term "hypochlorous acid" as used herein, unless indicated otherwise, refers to the non-dissociated acid with chemical formula HOCI.

The term "foaming agent" as used herein, unless indicated otherwise, refers to a substance that is capable of promoting the formation of an aqueous foam. In a preferred embodiment the first and second compartments are housed in a single container, with both the first and second compartments having separate dip tubes. The dip tubes extend to a mixing chamber comprising valve means wherein the alkaline aqueous hypochlorite solution and the acid aqueous foaming liquid are mixed together for discharge through the outlet.

The foaming agent employed in accordance with the present invention is preferably a surfactant. Suitable surfactants that may be used in the composition according to the present invention are anionic, zwitterionic, non-ionic or amphoteric surfactants, and mixtures thereof. More preferably, the foaming agent is an anionic surfactant or zwitterionic surfactant. Most preferably, the foaming agent is an anionic surfactant.

In a preferred embodiment, the foaming liquid comprises at least 0.1 wt.% of a foaming anionic surfactant, more preferably at least 0.5 wt.% of a foaming anionic surfactant, even more preferably at least 1.0 wt.% of a foaming anionic surfactant.

Preferably, the foaming liquid comprises at most 5 wt.% of a foaming anionic surfactant, more preferably at most 4 wt.% of a foaming anionic surfactant, even more preferably at most 3 wt.% of a foaming anionic surfactant. In a preferred embodiment, the foaming anionic surfactant is selected from sodium lauryl ether sulfate (SLES), sodium lauryl sulfate (SLS), ammonium lauryl sulfate and combinations thereof. In a particularly preferred embodiment, the foaming liquid comprises 0.2 to 2 wt.%, more preferably 0.3 to 1.5 wt.% and most preferably 0.5 to 1.0 wt.% of organic acid selected from citric acid, lactic acid, malonic acid, malic acid and combinations thereof. Most preferably the organic acid is citric acid.

The foaming liquid preferably has a pH in the range of 5 to 7, more preferably between 5.2 and 6.8, even more preferably between 5.2 and 6.8.

The foaming liquid preferably contains at least 90 wt.% water, more preferably at least 92 wt.% water and most preferably at least 94 wt.% water.

Preferably, the foaming liquid contains less than 5 wt.% ethanol, more preferably less than 3 wt.% ethanol, most preferably less than 1 wt.% ethanol. In accordance with a preferred embodiment, the foaming liquid contains less than 1 wt.% hydrogen peroxide, more preferably less than 0.5 wt.% hydrogen peroxide, even more preferably less than 0.2 wt.% hydrogen peroxide.

In accordance with a preferred embodiment, the hypochlorite solution contains 0.001 to 2.0 wt.%, more preferably 0.005 to 1.5 wt.%, even more preferably 0.007 to 1.0 wt.% and most preferably 0.01 to 0.5 wt.% of hypochlorite. The hypochlorite solution preferably has a pH in the range of 8 to 12, more preferably a pH in the range of 9 to 1 1 and even more preferably a pH in the range of 9 to 10. Preferably, the hypochlorite solution contains at least 90 wt.% water, more preferably at least 92 wt. % water and most preferably at least 94 wt. % water.

In a preferred embodiment, the hypochlorite solution contains less than 5 wt.% ethanol, more preferably less than 3 wt.% ethanol, more preferably less than 1 wt. % ethanol.

As per an especially preferred aspect of the invention the first compartment is substantially free of a foaming agent. By "substantially free of a foaming agent" is meant that the foaming agent is present in less than 2%, preferably less than 1 %, more preferably less than 0.1 % by weight and optimally absent from the first compartment.

The sanitizing foam that is produced by operating the valve means of the sanitising system preferably has a density of 0.1 to 0.3 g/ml, more preferably of 0.16 to 0.23 g/ml. Foam density can be determined by dispensing foam into a pre-weighed measuring cylinder, measuring the volume of the foam and weighing the measuring cylinder containing the foam. The measured weight to volume ratio corresponds to the density of foam.

In a preferred embodiment, the first compartment contains 25 to 2,000 ml, more preferably 50 to 1 ,200 ml of the hypochlorite solution liquid and the second

compartment contains 25 to 2,000 ml, more preferably 50 to 1 ,200 ml of the foaming liquid.

In a second aspect, the present invention relates to a sanitising kit comprising

♦ a first container comprising an alkaline aqueous hypochlorite solution, said

• a second container comprising an acid aqueous foaming liquid, said foaming liquid containing 0.1 to 5.0 wt.% of a foaming agent and having a pH in the range of 2 to 6, said second container comprising valve means operable to dispense the foaming liquid from the second container;

· instructions for use instructing users to simultaneously or successively (in random order) operate the valve means of the first and the second container to dispense the first the hypochlorite solution and the foaming liquid into a hand of a user.

In a preferred embodiment, the alkaline aqueous hypochlorite solution is dispensed in the form of a liquid and the acid aqueous foaming liquid is dispensed in the form of a foam. The alkaline aqueous hypochlorite solution in the first container preferably is an alkaline aqueous hypochlorite solution as used in the sanitising system according to the present invention. Likewise, the acid aqueous foaming liquid in the second container preferably is an acid aqueous foaming liquid as used in the sanitising system.

In a third aspect, the present invention relates to a method of sanitising hands using a sanitising system or a sanitizing kit according to the present invention, said method comprising operating the valve means of the sanitising system to dispense the sanitizing foam into a hand of a user or comprising operating in random order the valve means of the first and the second container to dispense the hypochlorite solution and the foaming liquid into a hand of a user.

The invention is further illustrated by the following non-limiting examples. Examples Example 1

The liquid components of a two-component sanitising systems were prepared on the basis of the formulation shown in Table 1 (percentages are weight percentages).

TABLE 1

separate compartments of a spraying device. Each compartment of the spraying device contained a dip tube that extended into the same mixing chamber. The spraying device further contained a manually operated pump system that pumped the fluids from the compartments into the mixing chamber and that expelled the mixture from this mixing chamber through a dispensing nozzle. Upon operation of the pump system the two liquid components were combined in the mixing chamber in a weight ratio of approximately 1 :1. Example 2

A sanitising foam was produced by operating the pump system of the spraying device described in Example 1. The foam had a density of approximately 0.2 g/ml. The hypochlorous acid concentration and the pH of the foam are given in Table 2.

TABLE 2

The antimicrobial efficacy of the sanitising foam was determined using a Microbial Contact Kill Assay. The liquid components of the sanitising foam were carefully mixed to produce an unfoamed sanitising liquid to facilitate the testing of the antimicrobial efficacy.

Method:

1. E.coli ATCC 10536 and S. aureus ATCC 6538 strains were revived from glycerol stock.

2. Single colonies of E.coli and S. aureus were picked from freshly revived plates and used to inoculate 10 ml of tryptic soy broth. The inoculated broth was kept shaking at 150 RPM in a shaker incubator at 37 °C for 3 hours. 3. After 3 hours of incubation, the optical density was adjusted to 0.08 at 625 nm with 1 cm path (0.5 McFarland standards corresponds with 10⁸ cells per ml)

4. Sterile milliQ® water was added to a 15 mL Tarson® tube which was kept in a water bath at 45 °C.

5. Next, 1 mL cells suspension (1 mL bacterial suspension of S. aureus (stock 10⁹ cells/mL) and E. coli (stock 10⁹ cells/mL), respectively) was added. So finally 10⁸ cells/mL in each reaction was added and allowed to equilibrate at 45°C for 2 minutes.

6. 1 mL of the unfoamed sanitising liquid was added to 2 mL of each of the above bacterial suspensions and mixed for 10 seconds, 30 seconds, 60 seconds or 5 minutes.

7. After these respective time periods, 1 mL samples was withdrawn from each 15 mL Tarson® tube and diluted with 9 mL Dey Engley Neutralizer (Cat#M1062) and was kept for 5 minutes at room temperature. This represents a 10^"1 dilution.

8. A serial dilution was made from the neutralized samples of step 7 and 100 μί of each dilution plated onto tryptic soy agar plates to give plates having dilutions of 10 \ 10^"2, 10^"3,10-⁴ and 10^"5.

9. Initial culture control was also done by performing serial dilutions of the initial control E.coli and S. aureus prepared in step 5, and by plating 100 μί onto tryptic soy agar plates to give plates having dilutions of 10^"1, 10^"2, 10 ³,10^"4, 10^"5,10^"6 and 10^"7.

10. All the plates were incubated at 37 °C for around 14 to 16 hours.

1 1. The concentration of cells/ml of the samples was calculated by following formula: Number of CFU/ml = Number of colonies X dilution factor / volume of plated culture

(mL)

12. The sample producing a colony count in the range of 30 to 300 was used in the above mentioned CFU calculation. The initial concentration of bacteria was 10⁸. The results of this test are summarized in Table 3.

TABLE 3

Example 3 The stability of the hypochlorous acid in the foaming liquid post mixing was measured using iodometric titration. The results are shown in Table 4.

TABLE 4

Table 4 shows that hypochlorous acid decomposes quickly after mixing meaning that the user's skin is not exposed to high concentration of active chlorine for a long time. Thus, the sanitizing system according to the present invention is ideal for hand sanitizing applications.

Claims

1. A sanitising system comprising:

• valve means operable to put both the first compartment and the second compartment in communication with an outlet;

wherein, upon operation of the valve means, the hypochlorite solution is mixed with the foaming liquid in a ratio of from 0.8:1 to 1 .3:1 respectively to produce an aqueous hypochlorous acid (HOCI) solution having a pH in the range of 5 to 7, and the aqueous hypochlorous acid solution is discharged through the outlet to form a sanitising foam.

2. Sanitising system according to claim 1 , wherein the foaming agent is a foaming surfactant.

3. Sanitising system according to claim 1 or 2, wherein the foaming liquid contains 0.1 to 5.0 wt.% of a foaming anionic surfactant.

4. Sanitising system according to claim 3, wherein the foaming anionic surfactant is selected from sodium lauryl ether sulfate, sodium lauryl sulfate, ammonium lauryl sulfate and combinations thereof.

5. Sanitising system according to any one of the preceding claims 1 to 4, wherein the foaming liquid comprises 0.5 to 0.8 wt.% of organic acid selected from citric acid, lactic acid, malonic acid, malic acid and combinations thereof.

6. Sanitising system according to any one of the preceding claims, wherein the foaming liquid has a pH in the range of 5 to 6.

7. Sanitising system according to any one of the preceding claims 1 to 6, wherein the foaming liquid contains at least 90 wt.% water.

8. Sanitising system according to any one of the preceding claims 1 to 7, wherein the foaming liquid contains less than 1 wt.% hydrogen peroxide.

9. Sanitising system according to any one of the preceding claims 1 to 8, wherein the hypochlorite solution contains at least 90 wt.% water.

10. Sanitising system according to any one of the preceding claim 1 to 9, wherein the sanitizing foam has a density of 0.1 to 0.3 g/ml.

1 1. Sanitising system according to any one of the preceding claims 1 to 10, wherein the first compartment contains 25 to 2,000 ml of the hypochlorite solution and the second compartment contains 25 to 2,000 ml of the foaming liquid.

12. A sanitising kit comprising:

♦ a first container comprising an alkaline aqueous hypochlorite solution, said hypochlorite solution containing 0.0010 to 2.0 wt.% of hypochlorite and having a pH in the range of 8 to 1 1 , said first container comprising valve means operable to dispense the hypochlorite solution from the first container;

♦ a second container comprising an acid aqueous foaming liquid, said

foaming liquid containing 0.1 to 5.0 wt.% of a foaming agent and having a pH in the range of 2 to 6, said second container comprising valve means operable to dispense the foaming liquid from the second container;

♦ instructions for use instructing users to simultaneously or successively operate the valve means of the first and the second container to dispense the hypochlorite solution and the foaming liquid into a hand of a user.

13. Kit according to claim 12, wherein the alkaline aqueous hypochlorite solution is dispensed as a liquid and the acid aqueous foaming liquid is dispensed in the form of a foam.

14. A method of sanitising hands using a sanitising system according to any one of claims 1 to 1 1 or a sanitizing kit according to claim 12 or 13, said method comprising operating the valve means of the sanitising system to dispense the sanitizing foam into a hand of a user or comprising operating in random order the valve means of the first and the second container to dispense the hypochlorite solution and the foaming liquid into a hand of a user.