HK1213433B - Improved antimicrobial compositions - Google Patents

Abstract

A antibacterial hand rub composition comprising at least 0.2% w/w isopropyl myristate, excluding other derivatives of myristic acid. The preferred concentration of phenoxyethanol in the composition is 1wt% or less. If the composition is an ethanol based hand rub gel, then the diol can also be such as dipropylene glycol. If the composition is in the form of lotion or dispersion, the glycol can also be propylene glycol. Additional fungicides may include substances such as triclosan and chlorhexidine gluconate.

Description

Improved antimicrobial compositions

Background

The use of alcohol as an antimicrobial dates back to the bible age and earlier. Alcohol-containing antibacterial compositions have been widely used in hospitals since at least 1990. In 1993, bruch et al (US5403864) indicated that:

"infection control and epidemiological experts have repeatedly emphasized that the most important element in reducing transmission of infection is hand washing, since in a medical setting, the common method of transfer between individuals is by hand. This fact has been painfully documented in the analysis of the spread of infectious diseases.

However, it seems obvious and easy to understand that medical personnel, including doctors and nurses, are reluctant to frequently wash or scrub their hands as required by their own regulations. It is estimated that the average hand washing time between patients is 10 seconds or less. The effectiveness of soap and water rinse is measured in minutes. Briefly, washing hands are not frequent enough.

When a health care worker touches the device or the patient with the hand, bacteria that do not belong to the normal skin flora are stained and easily adhere to the topmost layer of the skin, the stratum corneum. "

Since they were written in 1993 from these perspectives, they were still true in 2012. However, during the 20 years new and improved antimicrobial formulations have been developed and the importance of two additional facts has become apparent. First, some microorganisms are located deeper in the sub-stratum corneum. Secondly, the main reasons for non-compliance are dry chapping of the hands and skin irritation caused by rubbing with repeated alcohol or washing with aqueous biocides. Attempts to minimize irritation by the use of emollients have not been effective in increasing compliance either (i) because they produce a greasy feel after use of the emollient, (ii) because they reduce the speed at which hand washing is effective, or (iii) because the emollient is ineffective at reducing skin irritation at the required concentration, or a combination of these three reasons.

In 1995 bruch et al disclosed an antibacterial composition comprising triclosan, chloroxyphenol and ethanol, but this composition was not effective against subcutaneous organisms and although the inventors claimed that no signs of irritation were observed after multiple uses in the laboratory, many skin irritation cases were observed at the time of hospital use.

In 1998, Japani et al (US 6,022,551) indicated a need for an effective and non-irritating antimicrobial composition to the user and described a composition containing specific thickeners and phospholipids.

The inventors have found that the subjective feel of the composition, amongst other factors, also plays an important role in compliance and that "non-irritation" is not sufficient for the composition. Thus, if compliance is to be complete, workers may have to apply the composition to their hands at a frequency of 100 times per day. The inventors found that the worker's compliance rate was higher if they felt good than if they felt bad or worse than their good feeling formulation. One of the sensory influencing factors is the tendency of some alcoholic gel formulations to be pelletized, but others include greasiness. Moreover, other subjective factors play an important role in affecting the feel and compliance of the composition when used. Formulations that are generally evaluated by the worker as being perceived as superior to existing formulations are referred to herein as formulations having an "improved feel". One internationally recognized criteria for biocidal efficacy is that a defined dose of biocidal composition in contact with the hands over a defined period of time is at least as effective as 6ml of 60% v/v isopropanol over a contact period of 60 seconds (european standard EN1500:1997 sets forth the experimental procedure in detail entitled "test procedure and requirements for chemical disinfectants and biocidal sanitary wipes-anti-escherichia coli NCTC 10538 (stage 2/step 2)', referred to herein as" EN1500:1977 ").

Compositions for use as biocidal hand wipes comprise materials that improve skin conditioning and moisturization, such as moisturizers (e.g., glycerin), anti-inflammatory ingredients (e.g., isolene), and viscosity increasing/conditioning agents (e.g., phenyl dimethicone quaternary). However, skin "conditioning agents" are used to affect the moisturization, emolliency and condition of the skin to reduce irritation, rather than to affect the feel of the composition on the skin.

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or part of common general knowledge in the field.

Objects of the invention

It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

More specifically, it is an object of the present invention to provide a biocidal hand rub or hand sanitizer which avoids or ameliorates at least some of the above discussed disadvantages of the prior art and which, in a preferred embodiment, in addition to improving skin feel, produces a biocidal effect which is at least the same as that produced by rubbing a hand with 6ml of 60% v/v isopropanol for 60 seconds.

The preferred embodiment is suitable for repeated use by healthcare workers and meets internationally recognized standards of efficacy as healthcare workers move between patients or between different procedures on the same patient.

Compliance with biocidal regulations is better facilitated using the preferred embodiments.

Disclosure of Invention

According to a first aspect, the present invention discloses a biocidal hand rub composition which produces a biocidal effect which is equal to or greater than the biocidal effect produced in 60 seconds by 6ml of 60% v/v aqueous isopropanol (determined according to the test method of EN1500: 1977) when used at a rate of less than 6ml of the composition for 60 seconds, the composition being characterised by comprising at least 0.2% w/w isopropyl myristate.

Isopropyl myristate is the isopropyl ester of myristic acid (straight chain C14 saturated acid) having the following structure:

in a preferred embodiment, according to the first aspect, a rub of a hand with only 3ml of the ethanol-based biocidal hand rub gel composition for 30 seconds produces a biocidal effect which is at least as good as the biocidal effect produced by 6ml of 60% v/v isopropanol within 60 seconds (as determined according to the test method of EN1500: 1977). Compliance with hand rub protocols is greatly enhanced because the preferred embodiment provides the same or better biocidal effect at half the dose and half the time and the compositions of the present invention provide improved feel. Since the biocidal effect of ethanol is inferior to that of isopropanol, it is surprising that ethanol-based biocidal gels are effective.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, i.e., "including but not limited to".

In a preferred embodiment of the first aspect of the invention, the biocidal hand rub composition is an ethanol based biocidal hand rub composition comprising one or more glycols, preferably dipropylene glycol, or phenoxyethanol, or ethylene glycol and phenoxyethanol.

In a preferred embodiment, the biocide is an ethanol-based hand rub composition in the form of a gel.

In another preferred embodiment of the first aspect of the invention, the biocidal hand rub composition is in the form of an emulsion or suspension comprising one or more glycols, at least one of which is a low molecular weight ethylene glycol (preferably propylene glycol), or phenoxyethanol, or ethylene glycol and phenoxyethanol.

Preferably, the isopropyl myristate acts as an anti-pilling agent.

Preferably, the isopropyl myristate is the only derivative of myristic acid in the composition, i.e. the composition is specifically free of all other esters, salts or derivatives of myristic acid, such as ethyl or butyl myristate, or sodium myristate, myristamide DEA, etc.

The isopropyl myristate acts as an anti-pilling agent and improves the feel of the composition on skin. The present inventors have surprisingly found that at least 0.2% w/w isopropyl myristate comprised in an alcoholic hand rub containing ethylene glycol and phenoxyethanol (gel and aqueous emulsion) significantly improves the feel produced by the same and similar compositions that do not comprise isopropyl myristate. Even more surprising, the benefits of using isopropyl myristate (the C14 ester) as an anti-pilling agent include the ability to achieve skin feel not achieved with C12 or C14 isopropyl esters, C16 or C18 isopropyl esters, or other myristates.

For example, the same highly desirable feel cannot be obtained by replacing C10 isopropyl acetate, isopropyl acetate (decanoate) or C12 isopropyl laurate (dodecanoic acid). The same highly desirable feel could not be obtained by replacing the isopropyl C16 palmitate or isopropyl C18 stearate. The same highly desirable sensation could not be obtained by replacing isopropyl myristate with other similar compositions such as myristyl myristate.

Preferably, the alcoholic biocidal hand rub composition comprises substantially no C10, C12, C16 or C18 isopropyl esters, i.e. no isopropyl hexanoate (C10), isopropyl laurate (C12), isopropyl palmitate (C16) and isopropyl stearate (C18). By substantially free is meant that the isopropyl myristate is at least 90% pure C14.

Preferably, the isopropyl myristate is present in an amount of 0.1-2.0% w/w. More preferably, it is present in an amount of 0.2-0.8% w/w, or more preferably 0.2-0.5% w/w or 0.2-0.3% w/w.

Preferably, if the alcoholic biocidal hand rub composition is a gel, the isopropyl myristate is present at about 0.2%.

In another embodiment, the present invention provides a method of improving the skin feel of an ethanol-based biocidal hand rub composition by rubbing a hand with less than 6ml of said hand rub composition for 60 seconds to produce a biocidal effect equal to or greater than the biocidal effect produced by 6ml of 60% v/v isopropanol within 60 seconds (as measured according to the test method of EN1500: 1977), said method comprising the step of adding to the composition at least 0.2% w/w of isopropyl myristate.

The alcohol biocidal hand rub composition comprises ethylene glycol, or phenoxyethanol, or ethylene glycol and up to 1 wt% phenoxyethanol. In a preferred embodiment, it may be in the form of a gel or an emulsion or suspension.

Preferably, the isopropyl myristate is added as an anti-pilling agent.

Preferably, the isopropyl myristate is selected as the only derivative of myristic acid in the composition and the method avoids the use of formulations containing C10, C12, C16 or C18 isopropyl esters, i.e. the method of improving skin feel avoids the use of isopropyl hexanoate (C10), isopropyl laurate (C12), isopropyl palmitate (C16) and isopropyl stearate (C18).

In another aspect, the present invention provides a biocidal hand rub composition characterized in that it comprises at least 0.2% w/w isopropyl myristate. Preferably, the composition is free of any isopropyl adipate, isopropyl laurate, isopropyl palmitate and isopropyl stearate. Preferably, isopropyl myristate is the only derivative of myristic acid in the composition.

Preferably, the concentration of isopropyl myristate is 0.2% -0.5%.

Preferably, the composition comprises phenoxyethanol. Preferably, the concentration of phenoxyethanol is 1 wt% or less.

Preferably, the composition is in the form of an ethanol-based hand rub or in the form of an emulsion or suspension.

Preferably, the composition contains one or more glycols.

In a preferred embodiment, the composition is an ethanol-based hand rub gel, in which case the glycol is preferably dipropylene glycol. Preferably, the weight percentage of the dipropylene glycol is 0.25-4 times of the weight percentage of the isopropyl myristate. Preferably, the weight percentage of the dipropylene glycol is 1% of the weight percentage of the composition.

In a particularly preferred embodiment of the invention, the invention provides a formulation comprising: ethanol, phenoxyethanol, ethylene glycol and isopropyl myristate, and does not contain any other myristic acid derivatives. The formulation does not contain any other myristic acid derivatives.

The content of ethanol is preferably 50-80% w/w, more preferably 60-65% w/w. The content of dipropylene glycol is preferably 0.2-0.8% w/w, more preferably 0.4-0.6% w/w. The content of phenoxyethanol is preferably 0.2-1.0% w/w, more preferably 0.5-0.6% w/w. The isopropyl myristate is preferably present in an amount of 0.1-0.3, more preferably about 0.2% w/w.

In an alternative preferred embodiment, the composition is in the form of an emulsion or dispersion, in which case at least one of the diols is a low molecular weight diol, preferably propylene glycol. Preferably, the weight percentage of the propylene glycol is 0.25-4 times of the weight percentage of the isopropyl myristate. Preferably, the weight percentage of the propylene glycol is 1% of the composition.

The biocidal composition may include one or more additional biocides. Preferably, the additional biocide is triclosan and chlorhexidine gluconate.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The formulations of examples 1-8 were prepared. Each formulation contains 0.2-0.5% w/w isopropyl myristate. The following examples 1-5 illustrate the alcohol hand rub gels of the present invention. Examples 6-8 below illustrate aqueous emulsions or suspensions.

Example 1 (70% v/v ethanol, CHG 0.5% w/w biocidal gel):

example 2 (70% v/v ethanol, triclosan 1.0% w/w biocidal gel)

Example 3 (70% v/v ethanol biocidal gel)

Example 4 (70% v/v ethanol biocidal gel)

Example 5 (70% v/v ethanol, CHG 2.0% w/w surgical gel)

Examples 6-8 below are aqueous biocidal emulsions or suspensions.

Example 6 (CHG 1% w/w biocidal emulsion)

Example 7(CHG 2% w/w surgical emulsion)

Example 8 (triclosan 0.5% w/w biocidal emulsion)

Method-part 1 experiment A, B, C-related to ethanol-based biocidal hand rub gel

The following comparative tests were carried out with respect to skin feel:

various alcoholic gel biocidal formulations based on example 3 were formulated with isopropyl myristate removed from the formulation, others remaining unchanged and various isopropyl esters, myristyl myristate, glyceryl laurate-all of which are emollients. After repeated use, the skin feel of these emollients was compared to the market leading alcohol gel biocide by an experienced panel.

A. The ethanol biocidal gel formulation described in example 3 above was used to formulate the following skin feel test formulations:

1. isopropyl myristate was omitted and not replaced.

2. The isopropyl myristate was omitted and replaced by C10 isopropyl myristate in example 3.

3. The isopropyl myristate was omitted and replaced by C12 isopropyl myristate in example 3.

4. Isopropyl myristate was added.

5. The isopropyl myristate was omitted and replaced by C16 isopropyl myristate in example 3.

6. The isopropyl myristate was omitted and replaced by C18 isopropyl myristate in example 3.

7. Isopropyl myristate was omitted and replaced by myristyl myristate in example 3.

8. Isopropyl myristate was omitted and replaced by glycerol laurate for isopropyl myristate in example 3.

9. Vigorous in the United statesHand-rubbing liquid with alcohol.

B. Various contents of isopropyl myristate. The ethanol biocidal gel formulation described in example 3 above was used to formulate the following skin feel test formulations:

1. formulations without isopropyl myristate.

2. Formulations containing 0.1% w/w isopropyl myristate.

3. Formulations containing 0.2% w/w isopropyl myristate.

4. A formulation containing 0.35% w/w isopropyl myristate.

5. Formulations containing 0.5% w/w isopropyl myristate.

6. Formulations containing 0.8% w/w isopropyl myristate.

C. Various levels of ethylene glycol, in this case dipropylene glycol (DPG), were added to example 3, the others were unchanged, and these were used to assess skin feel. The content of dipropylene glycol (DPG) added in example 3 was:

1. formulations containing 0.1% w/w dipropylene glycol.

2. Formulations containing 0.5% w/w dipropylene glycol.

3. Formulations containing 0.8% w/w dipropylene glycol.

4. Formulations containing 1.0% w/w dipropylene glycol.

5. Formulations containing 1.3% w/w dipropylene glycol.

First, both hands were washed with biocidal hand washes following standard hospital hand washing procedures and wiped dry with paper towels and then dried for 5 minutes. Next, 3ml of each test product was applied to both hands and rubbed to dryness. The skin feel was recorded after a few minutes. After 5 minutes of the first application, the test product was applied to both hands a second time and the experimental procedure was repeated. This sequence was repeated 4 times and 3ml applications were made every 5 minutes. After the 5 th application, the feel and pilling of the skin were recorded for 1 minute after drying the hands.

The experiments were performed in 3 occasions, each time at a different location, in a panel of 10 experienced workers. The results are as follows: "IPM" refers to isopropyl myristate and "DPG" refers to dipropylene glycol.

The interviewee can select from a limited number of descriptive results with a sufficient range of choices to encompass all possible results. The interviewee was asked to grade the sensation as "light" or "heavy" and to grade the sensation as one or more of "dry" or "smooth" or "waxy", "greasy" or "oil". The number of interviewees who provided the primary skin sensation outcome ("res") was recorded in the results column.

Method-part 2 experiment D, E, F-related to biocidal hand rub emulsions/suspensions

Various aqueous emulsion (lotion) biocidal formulations were formulated with isopropyl myristate removed from the formulation, others remaining unchanged and various isopropyl esters, myristyl myristate, glyceryl laurate-all of which are emollients. After repeated use, the skin feel of these emollients was compared by an experienced panel.

D. The aqueous biocidal emulsion formulation described in example 8 was used to formulate the following skin feel test formulation:

1. isopropyl myristate was omitted and not replaced.

2. The isopropyl myristate was omitted and replaced by C10 isopropyl myristate in example 8.

3. The isopropyl myristate was omitted and replaced by C12 isopropyl myristate in example 8.

4. Isopropyl myristate was added.

5. The isopropyl myristate was omitted and replaced by C16 isopropyl myristate in example 8.

6. The isopropyl myristate was omitted and replaced by C18 isopropyl myristate in example 8.

7. Isopropyl myristate was omitted and replaced by myristyl myristate in example 8.

8. Isopropyl myristate was omitted and replaced by glycerol laurate for isopropyl myristate in example 8.

E. Various contents of isopropyl myristate:

the aqueous biocidal emulsion formulation described in example 8 above was used to formulate the following skin feel test formulation:

1. formulations without isopropyl myristate.

2. Formulations containing 0.2% w/w isopropyl myristate.

3. Formulations containing 0.5% w/w isopropyl myristate.

4. Formulations containing 0.8% w/w isopropyl myristate.

5. Formulations containing 1.0% w/w isopropyl myristate.

6. Formulations containing 1.3% w/w isopropyl myristate.

F. Various levels of ethylene glycol, in this case Propylene Glycol (PG), were added to example 8, the others were unchanged, and these were used to assess skin feel.

1. Formulations containing 0.2% w/w propylene glycol.

2. Formulations containing 0.5% w/w propylene glycol.

3. Formulations containing 0.8% w/w propylene glycol.

4. Formulations containing 1.0% w/w propylene glycol.

5. Formulations containing 1.3% w/w propylene glycol.

First, both hands were washed with biocidal hand washes following standard hospital hand washing procedures and wiped dry with paper towels and then dried for 5 minutes. Next, 4ml of each experimental product was spread on both hands and rubbed to dryness. The skin feel was recorded after a few minutes. After 5 minutes of the first application, the test product was applied to both hands a second time and the experimental procedure was repeated. This sequence was repeated 2 times and 4ml applications were made every 5 minutes. After the 3 rd application, skin feel was recorded for 1 minute after drying the hands.

The experiments were performed in 3 occasions, each time at a different location, in a panel of 10 experienced workers. The results are as follows: "IPM" refers to isopropyl myristate and "PG" refers to propylene glycol.

The number of interviewees who provided the primary skin sensation results is recorded in the results column.

The interviewee can select from a limited number of descriptive results with a sufficient range of choices to encompass all possible results.

Results-part 1 experiment A, B, C-related to ethanol-based biocidal hand rub gel

Tests to date have shown that inclusion of at least 1% w/w isopropyl myristate (IPM) does not adversely affect the biocidal effect of the compositions of the present invention.

For example, the alcohol hand rub of example 3 of the invention was in accordance with the requirements of the european standard experiment. The european norm is 3.29 orders of magnitude reduction after 30 seconds of wiping with 3ml of product compared to the reference product, 3.33 orders of magnitude reduction after 60 seconds of contact with 6ml (60% v/v isopropanol) of product (although there is a difference in quantity and time, the difference in order of magnitude reduction is not statistically significant).

TABLE 1 Experiment A, results in site 1

The skin feel effect produced by the various isopropyl esters compared to the market leading product is as follows:

the conclusion that can be drawn from the results of table 1 above is:

1. repeated cycles of the composition containing isopropyl myristate produced skin feel better than any other isopropyl ester containing composition tested.

2. Repeated cycling of the composition containing isopropyl myristate resulted in a better skin feel combination with minimal pilling compared to the other test compositions.

TABLE 2 Experiment B-site 1

Effect of IPM concentration on skin feel

The conclusion that can be drawn from the results of table 2 above is:

various levels of isopropyl myristate were added to the compositions and after repeated cycles, the experiments were dependent on the preferred composition containing isopropyl myristate at levels of 0.2%, 0.35% and 0.5%. Of these contents, the content of 0.2% is superior to the contents of 0.35% and 0.5% to some extent.

TABLE 3 experiment C-site 1

Effect of the concentration of dipropylene glycol on skin feel

The conclusion that can be drawn from the results of table 3 above is:

various levels of dipropylene glycol were added to the composition, and after repeated recycling, the experiments were dependent on the preferred composition containing dipropylene glycol at levels of 0.5%, 0.8%, and 1.0%. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

TABLE 4 results of experiment A, site 2

The skin feel effect produced by the various isopropyl esters compared to the market leading product is as follows:

the conclusion that can be drawn from the results of table 4 above is:

1. repeated cycles of the composition containing isopropyl myristate produced skin feel better than any other isopropyl ester containing composition tested.

2. Repeated cycling of the composition containing isopropyl myristate resulted in a better skin feel combination with minimal pilling compared to the other test compositions.

TABLE 5 experiment B, site 2

Effect of IPM concentration on skin feel

The conclusion that can be drawn from the results of table 5 above is:

various levels of isopropyl myristate were added to the compositions and after repeated cycles, the experiments were dependent on the preferred composition containing isopropyl myristate at levels of 0.2%, 0.35% and 0.5%. Of these contents, the content of 0.2% is superior to the contents of 0.35% and 0.5% to some extent.

TABLE 6 experiment C, site 2

Effect of the concentration of dipropylene glycol on skin feel

The conclusion that can be drawn from the results of table 6 above is:

various levels of dipropylene glycol were added to the composition, and after repeated recycling, the experiments were dependent on the preferred composition containing dipropylene glycol at levels of 0.5%, 0.8%, and 1.0%. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

TABLE 7 results of experiment A, site 3

The skin feel effect produced by the various isopropyl esters compared to the market leading product is as follows:

the conclusion that can be drawn from the results of table 7 above is:

1. repeated cycles of the composition containing isopropyl myristate produced skin feel better than any other isopropyl ester containing composition tested.

2. Repeated cycling of the composition containing isopropyl myristate resulted in a better skin feel combination with minimal pilling compared to the other test compositions.

TABLE 8 experiment B, site 3

Effect of IPM concentration on skin feel

The conclusion that can be drawn from the results of table 8 above is:

various levels of isopropyl myristate were added to the compositions and after repeated cycles, the experiments were dependent on the preferred composition containing isopropyl myristate at levels of 0.2%, 0.35% and 0.5%. Of these contents, the content of 0.2% is superior to the contents of 0.35% and 0.5% to some extent.

TABLE 9 experiment C, site 3

Effect of the concentration of dipropylene glycol on skin feel

The conclusion that can be drawn from the results of table 9 above is:

various levels of dipropylene glycol were added to the composition, and after repeated recycling, the experiments were dependent on the preferred composition containing dipropylene glycol at levels of 0.5%, 0.8%, and 1.0%. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

General conclusion of experiment A, B, C and sites 1-3

It is noted that for tests A, B and C, the preferred compositions selected by the panelists at each site were the same. The results are consistent indicating clearly discernable differences in the in-person experience and results of panelists.

Experiment A

With respect to skin feel and pilling, most panelists in three locations agreed on compositions with preferred emollients. They specifically selected the formulation with isopropyl myristate.

Experiment B

Most panelists agreed that the formulation with IPM produced a significantly better sensation than any of the other tested formulations. Not only after the first application but also after repeated applications. Similar results were obtained with other exemplified formulations, isopropyl myristate at a concentration of 0.5% w/w and an optimum content of isopropyl myristate of 0.2%.

As will be appreciated by those skilled in the art, the biocidal composition may be formulated with other ingredients and other concentrations without departing from the inventive concept disclosed herein, i.e., the addition of isopropyl myristate to improve the feel of the product and enhance the propensity for use.

Experiment C

For experiment a, most panelists agreed on compositions with the preferred level of dipropylene glycol with respect to skin feel and pilling. The results remained consistent throughout the life cycle. The dipropylene glycol content added to the preferred composition is 0.5%.

Results-part 2 experiment D, E, F relating to biocidal hand rub emulsions and suspensions

The aqueous hand-wiping liquid (emulsion) meets the requirements of European standard experiments. The european norm is a reduction of 3.77 orders of magnitude after 60 seconds of wiping with 4ml of product compared to the reference product, and a reduction of 4.04 orders of magnitude after 60 seconds of contact with 6ml (60% v/v isopropanol) of product (although there is a difference in quantity and time, the difference in order of magnitude reduction is not statistically significant).

Watch 10 Experiment D, results in site 1

Skin feel compared to isopropyl esters

The conclusion that can be drawn from the results of table 10 above is:

repeated cycling of the composition containing isopropyl myristate produced skin feel superior to that produced by various other isopropyl esters containing the tested composition.

TABLE 11 results of experiment D, site 2

Skin feel compared to isopropyl esters

The conclusion that can be drawn from the results of table 11 above is:

repeated cycles of the composition containing isopropyl myristate produced skin feel better than any other isopropyl ester containing composition tested.

TABLE 12 results of experiment D, site 3

Skin feel compared to isopropyl esters

The conclusion that can be drawn from the results of table 12 above is:

repeated cycling of the composition containing isopropyl myristate produced skin feel better than that produced by any of the various isopropyl esters containing the compositions tested.

TABLE 13 results of experiment E, site 1

Sensory effects resulting from varying the concentration of IPM

The conclusion that can be drawn from the results of table 13 above is:

various levels of isopropyl myristate were added to the compositions and after repeated cycles, the experiments were dependent on the preferred composition containing isopropyl myristate at levels of 0.5%, 0.8% and 1.0%. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

TABLE 14 experiment E, site 2

Sensory effects resulting from varying the concentration of IPM

The conclusion that can be drawn from the results of table 14 above is:

various levels of isopropyl myristate were added to the compositions and after repeated cycles, the experiments were dependent on the preferred composition containing isopropyl myristate at levels of 0.5%, 0.8% and 1.0%. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

TABLE 15 experiment E, site 3

Sensory effects resulting from varying the concentration of IPM

The conclusion that can be drawn from the results of table 15 above is:

various levels of isopropyl myristate were added to the compositions and after repeated cycles, the experiments were dependent on the preferred composition containing isopropyl myristate at levels of 0.5%, 0.8% and 1.0%. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

TABLE 16 experiment F-site 1

Sensory effects produced by varying the amount of propylene glycol

The conclusion that can be drawn from the results of table 16 above is:

various levels of propylene glycol were added to the composition, with the propylene glycol levels being 0.5%, 0.8% and 1.0% depending on the preferred composition containing propylene glycol after repeated recycling. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

TABLE 17 EXPERIMENT F-site 2

Changing the level of propylene glycol the resulting sensory effect

The conclusion that can be drawn from the results of table 17 above is:

various levels of propylene glycol were added to the composition, with the propylene glycol levels being 0.5%, 0.8% and 1.0% depending on the preferred composition containing propylene glycol after repeated recycling. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

TABLE 18 EXPERIMENT F-site 3

Sensory effects produced by varying the amount of propylene glycol

The conclusion that can be drawn from the results of table 18 above is:

various levels of propylene glycol were added to the composition, with the propylene glycol levels being 0.5%, 0.8% and 1.0% depending on the preferred composition containing propylene glycol after repeated recycling. Of these contents, the content of 0.5% is superior to the contents of 0.8% and 1.0% to some extent.

General conclusions regarding emulsions in all experiments D, E, F and sites

Notably, for test D, E, F, the preferred compositions selected by the panelists at each site were the same. The results are consistent indicating clearly discernable differences in the in-person experience and results of panelists.

Experiment D

With respect to skin feel, most panelists in three locations agreed on compositions with preferred emollients. They specifically selected the formulation with isopropyl myristate.

Experiment E

Most panelists agreed that the formulation with IPM produced a significantly better sensation than any other experimental formulation. Not only after the first application but also after repeated applications. Similar results were obtained with other exemplified formulations, isopropyl myristate at a concentration of 1.0% w/w and an optimum content of isopropyl myristate of 0.5%.

In tables 10-18, example 8, which contains triclosan as a biocide, was used. In mind, the substitution of triclosan for chlorhexidine gluconate yielded substantially equivalent results in skin feel.

As will be appreciated by those skilled in the art, the biocidal composition may be formulated with other ingredients and other concentrations without departing from the inventive concept disclosed herein, i.e., the addition of isopropyl myristate to improve the feel of the product and enhance the propensity for use.

Experiment F

For experiment D, most panelists agreed on compositions with the preferred level of propylene glycol with respect to skin feel and pilling. The results remained consistent throughout the life cycle. In a preferred composition, the propylene glycol is added in an amount of 0.5%.

Claims (28)

1. A non-pilling biocidal hand rub gel, solution, emulsion or suspension which produces a biocidal effect equal to or greater than that produced by 6ml of 60% v/v aqueous isopropanol within 60 seconds when used at a rate of less than 6ml of the composition for 60 seconds as determined according to the test method of EN1500:1997, characterised in that the composition comprises phenoxyethanol and at least 0.2% w/w to 0.3% w/w of isopropyl myristate as an anti-pilling agent.

2. A non-pilling biocidal hand rub composition according to claim 1 wherein rubbing a hand with 3ml of said composition for 30 seconds produces a biocidal effect substantially the same as or better than 6ml of 60% v/v isopropanol within 60 seconds as measured according to the test method of EN1500: 1997.

3. The non-pilling biocidal hand rub composition according to claim 1 or 2, wherein said composition is an ethanol based biocidal hand rub composition.

4. The non-pilling biocidal hand rub composition according to claim 3, free of isopropyl hexanoate, isopropyl laurate, isopropyl palmitate and isopropyl stearate.

5. The non-pilling biocidal hand rub composition according to claim 3 wherein isopropyl myristate is the only derivative of myristic acid in the composition.

6. The non-pilling biocidal hand rub composition according to claim 2 comprising a glycol.

7. The non-pilling biocidal hand rub composition according to claim 6 wherein said glycol is or includes dipropylene glycol in a weight percentage of 0.25-4 times the weight percentage of isopropyl myristate.

8. The non-pilling biocidal hand rub composition according to claim 2 comprising phenoxyethanol at a concentration of 1 wt% or less.

9. The non-pilling biocidal hand rub composition according to claim 2 comprising ethylene glycol and phenoxyethanol in a percentage by weight of 1% of the composition.

10. The non-pilling biocidal hand rub composition of claim 2 comprising dipropylene glycol and phenoxyethanol.

11. The non-pilling biocidal hand rub composition according to claim 2 wherein said composition is in the form of a gel.

12. The non-pilling biocidal hand rub composition according to claim 1 wherein said composition is in the form of an emulsion or suspension.

13. The non-pilling biocidal hand rub composition according to claim 12 free of isopropyl hexanoate, isopropyl laurate, isopropyl palmitate and isopropyl stearate.

14. A non-pilling biocidal hand rub composition according to claim 12 or 13 wherein isopropyl myristate is the only derivative of myristic acid in the composition.

15. The non-pilling biocidal hand rub composition according to claim 12 comprising one or more glycols.

16. The non-pilling biocidal hand rub composition according to claim 15 wherein at least one glycol is a low molecular weight ethylene glycol.

17. The non-pilling biocidal hand rub composition according to claim 16 wherein the low molecular weight ethylene glycol is propylene glycol.

18. The non-pilling biocidal hand rub composition according to claim 12 comprising phenoxyethanol at a concentration of 1 wt% or less.

19. The non-pilling biocidal hand rub composition of claim 12 comprising ethylene glycol and phenoxyethanol in a weight percentage of 1% of the weight percentage of said composition.

20. The non-pilling biocidal hand rub composition of claim 12 comprising propylene glycol and phenoxyethanol.

21. A method of improving the skin feel of a biocidal hand rub composition which produces an effect equal to or greater than the biocidal effect produced by rubbing a hand with 6ml of 60% v/v isopropanol for 60 seconds, characterised in that the method includes the step of adding to the hand rub composition phenoxyethanol and 0.2% w/w to 0.3% w/w isopropyl myristate for use as an anti-pilling agent.

22. The method of claim 21, wherein the hand rub composition comprises one or more glycols.

23. The method of any one of claims 21-22, wherein the hand rub composition comprises ethylene glycol and phenoxyethanol.

24. The method of claim 23, wherein the glycol is or includes dipropylene glycol at a weight percentage of 0.25 to 4 times a weight percentage of isopropyl myristate.

25. The method of claim 21, wherein the hand rub composition is in the form of a gel.

26. The method of claim 21, wherein the hand rub composition is in the form of an emulsion.

27. The method of claim 21, wherein the isopropyl myristate is the only derivative of myristic acid in the composition.

28. The method of claim 21, wherein the isopropyl myristate is free of isopropyl caproate, isopropyl laurate, isopropyl palmitate, and isopropyl stearate.