Patent Grant
8562907
The present invention relates to a hand sanitizer.
The rise of hospital-acquired infections such as MRSA and Clostridium difficile has emphasized the need for cleanliness. In particular, effective hand sanitizing is needed for people working in a clinical environment.
Aspects of the invention are specified in the independent claims. Preferred features are specified in the dependent claims.
The invention provides the benefits of an antibacterial alcohol hand wash and sanitizer with the sporicidal properties of chlorine dioxide (ClO2).
The alcohol is or contains 3-methoxy-3-methylbutan-1-ol (MMB) which we have found to provide fast drying times and improved skin feel compared to ethanol. Other alcohols may optionally be included, notably ethanol, isopropanol, n-propanol or a mixture of these.
We have surprisingly found that producing ClO2 in an the presence of a substantial quantity of an alcohol does not noticeably result in disagreeable oxidized products of the alcohol, such as acetaldehyde or acetic acid from ethanol. Without wishing to be bound by theory, we believe that the short time during which the ClO2 is in contact with the alcohol when the liquids are mixed does not allow oxidation of the alcohol to a level where the smell of oxidized product is noticeable. Moreover, we have surprisingly found that sodium chlorite is stable in an alcoholic medium for extended periods, despite its being an oxidizing agent.
The dispenser may be a conventional trigger-operated pump or sprayer in which the contents are expelled manually by operation of the trigger by the user. Alternatively, the dispenser may contain a propellant to dispense the contents when operation of the trigger opens a valve. Suitable dispensers will be well known to those skilled in the art.
In a preferred embodiment, the first dispenser and the second dispenser are connected together or provided in a common housing. Preferably, both parts are dispensed simultaneously by operation of a single trigger or other actuator. A dual dispenser such as described in U.S. Pat. No. 5,152,461 may be used to dispense the two parts. The dispenser consists of two pump systems, with a single trigger operating both chambers. It is a mechanical dispenser which dispenses the two components simultaneously in a precise and fixed ratio. The first part and the second part are kept separate until the moment of application. Alternatively, a touchless dispenser may be used, which automatically dispenses a dual spray or jet of liquid or gel when a user's hands are detected to be in a suitable position.
The first and second parts are each dispensed as a spray of droplets or a jet of liquid, followed by mixing on the user's hands. To facilitate manipulation on the hands, and cling to the hands, each liquid may optionally be thickened or gelled to provide a more viscous liquid. For convenience the term ‘liquid’ is used herein to include gels.
Suitable gelling agents will be well known to those skilled in the art. Non-limiting examples include hydroxyalkylcelluloses, notably hydroxyethylcellulose or hydroxypropylcellulose, gelatine, poly(vinyl alcohol), alginates, carboxymethylcellulose, carrageenan, guar gum, gum agar, gum Arabic, gum ghatti, gum karaya, gum tragacanth, locust bean gum, pectins, polyacrylamide, polyacrylic acid and its homologues, polyethylene glycol, poly(vinyl pyrrolidone), starch and modified starches, tamarind gum, xanthan gum. The gelling agents are selected to provide a stable gel structure of a desired viscosity. The gelling agent may comprise from about 0.1 to 5% by weight of each part, notably from about 0.5 to 3%, preferably from about 1 to 2%.
In a preferred embodiment, a humectant is included in at least one of the first and second parts, preferably in both parts. Humectants serve to reduce the rate of evaporation of components and improve product feel if direct skin contact is involved. We have found that the use of a humectant reduces the volatility of chlorine dioxide, which reduces the odour of chlorine dioxide and prolongs the life of the activated mixture. Non-limiting examples of suitable humectants include sodium lactate and polyols, for example glycerine, sorbitol, propylene glycol, diethylene glycol and ethylene glycol. The humectant may be present in any desired amount, particularly from about 0.1 to 50% by weight, notably from about 0.5 to 10%, preferably from about 1 to 3%.
The invention will now be further described, by way of example only, with reference to the following drawings in which:
In this specification, all parts are by weight unless otherwise indicated.
The hand sanitizer 2 shown in
In the present example, the first part 14 is made up to the formulation of Table 1. The second part 16 is made up to the formulation of Table 2.
The first part and the second part are miscible to produce ClO2. However, they are kept separate from each other until the point of dispensing, thereby ensuring that ClO2 is formed only within a mixture of the liquids.
Referring now to
In the embodiment illustrated in
In use, the common housing 8 is disposed within an opening in the housing 34, and secured by an upper jaw member 36 and a lower jaw member 38 which engage with corresponding features 40, 42 on a dispensing mechanism 44. In this example, the lower jaw member 38 is operably connected to the motor (not shown). When the proximity sensor 32 detects a user's hands 24 under the nozzles 32,34, the control unit actuates the motor to lift the lower jaw member 38, which in turn lifts the engaging feature 42 and causes the first part 14 and second part 16 to be simultaneously dispensed as a spray of fine droplets of liquid. The sprays mix to form the sanitizing composition 26 on the user's hands 24, and the user rubs both hands together to mix the liquids thoroughly and cover both hands with the sanitizing composition 26.
After the user's hands have been thoroughly sanitized by covering and rubbing with the mixture 26, the user may rinse off the mixture 26. However, the alcohol content makes the mixture quite volatile and the user may choose simply to allow his hands to dry by evaporation.
Antibiotics, antivirals, or other antimicrobial agents may optionally be incorporated in either or both of the first part and the second part. Suitable agents will be well known to those of ordinary skill in the art. Examples include cationics, amphoterics and phenolics.
Humectants, moisturizers and fragrances may optionally be included in the first part or (preferably) the second part, as is well known in the art per se.
Corrosion inhibitors may be included in the first part and/or the second part, for improved packaging and protection of the dispenser.
The embodiment of Table 1 provides liquids which contain 25% alcohol and, when combined, chlorine dioxide, which we have found provides excellent sterilizing properties when used as a hand sanitizer.
The embodiment of Table 1 was tested for effectiveness against a range of micro-organisms using a method in accordance with EN 13727. Results are given in Table 3.
Staphylococcus
aureus
Pseudomonas
aeruginosa
Enterococcus
hirae
Escherichia coli
We have found that use of MMB as some or all of the alcohol component can provide the benefits of fast drying and greatly improved skin feel compared to ethanol. MMB also has the benefit over ethanol that it is substantially non-flammable. Pure MMB has a flash point of 68° C. measured by Tag Closed Cup, while a mixture of MMB and 10% or more water has no flash point. MMB is considered to be extremely safe, having no R and S phrases and Occupational Exposure Limit.
Table 4 summarises comparative drying speeds of mixtures of MMB and water, and mixtures of ethanol and water. In each case, a 0.1 ml sample was visually assessed for speed of drying. Rates of evaporation were determined by placing a sample onto a standard filter paper and measuring the time for complete evaporation. The time for diethyl ether evaporation is taken as unity, and the quoted numbers for each sample are expressed relative to diethyl ether.
The above demonstrates a similar evaporation rate for comparable solutions of ethanol in water and MMB in water. Qualitative testing demonstrated a greatly improved skin feel of MMB over ethanol.
Although MMB is used because of its very low flammability and good skin feel, other alcohols such as ethanol, propanol or isopropanol may also be used in the formulation in combination with MMB. We have surprisingly found that producing ClO2 in the presence of a substantial quantity of an alcohol does not noticeably result in disagreeable oxidized products of the alcohol, such as acetaldehyde or acetic acid from ethanol. Without wishing to be bound by theory, we believe that the short time during which the ClO2 is in contact with the alcohol when the liquids are mixed does not allow oxidation of the alcohol to a level where the smell of oxidized product is noticeable. Moreover, we have surprisingly found that sodium chlorite is stable in an alcoholic medium containing up to 80% ethanol for extended periods, despite its being an oxidizing agent. Accordingly, the invention can provide a hand sanitizer which dispenses liquid or gel components that provide the germicidal benefits of both ClO2 and alcohol.
We investigated a number of additives for incorporation in the acidic phase (Table 2) to reduce potential skin irritation caused by repetitive use of the formulation. The additives investigated were:
Each additive was included in the formulation of Table 2 at between 1% and 5% by weight. Trials demonstrated that additive 6), Meadowfoam delta-lactone was most effective.
Irritation Protocol
Using the acid phase of Table 2, a cotton wool pad was wetted and applied to a 3 cm area on the inside of both forearms of the volunteer subjects. Reaction to the application was monitored by noting the time when there was a sensation of irritation. Results are given in Table 5.
While this test does not specifically measure anti-irritancy with respect to reducing irritation caused by an applied insult, it clearly demonstrates that Meadowfoam delta-lactone provides an effective anti-irritation performance in at least some subjects.
It will be understood that, since the chlorite and the acid liquids will be mixed on application to a user's hands, the anti-irritant agent may be contained in either or both of the liquid phases.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1016332.7 | Sep 2010 | GB | national |
This application is a National Stage Application of PCT/GB2011/051768, filed 20 Sep. 2011, which claims benefit of Ser. No. 61/387,729, filed 29 Sep. 2010 in the United States of America, and Serial No. 1016332.7, filed 29 Sep. 2010 in Great Britain and which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/GB2011/051768 | 9/20/2011 | WO | 00 | 4/23/2013 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2012/042243 | 4/5/2012 | WO | A |
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| Entry |
|---|
| International Search Report for International Application No. PCT/GB2011/051768 mailed Mar. 13, 2012. |
| International Preliminary Report on Patentability for International Application No. PCT/GB2011/051768 mailed Oct. 9, 2012. |
| Number | Date | Country | |
|---|---|---|---|
| 20130202484 A1 | Aug 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61387729 | Sep 2010 | US |
