Patent Grant
9930888
The present invention relates to an improved antimicrobial composition comprising a lactam.
WO 2007/085042 and WO 2004/016588 disclose lactams for antimicrobial benefit.
Despite the prior art there remains a need for improved antimicrobial compositions.
Accordingly, and in a first aspect of the present invention there is provided an antimicrobial composition comprising a lactam and a hydrotrope preferably wherein the lactam is of formula (I) or (II):
In a second aspect, there is provided an antimicrobial additive composition containing a lactam and a hydrotrope.
Preferably the anti-microbial composition and additive composition contains 0.000001 to 50% wt. lactam, more preferably 0.001 to 50% wt. even more preferably 0.01 to 5% wt, most preferably 0.01-2%.
In a third aspect of the invention there is provided an antimicrobial composition comprising an antimicrobial additive composition of the second aspect.
In a fourth aspect there is provided a method for making an antimicrobial composition comprising the steps:
In a fifth aspect there is provided a method for making an antimicrobial additive composition comprising the step of directly mixing a hydrotrope with a lactam.
In a sixth aspect, the present invention provides the use of an antimicrobial composition according to the first and third aspect or an antimicrobial additive composition according to the second aspect for preventing or disrupting microbial growth.
Preferably the antimicrobial additive composition and the method of making said additive composition is substantially free of further components.
The term “substantially free” as used herein shall be understood to mean relatively little to no amount of any content. Preferably the antimicrobial contains less than 1 wt. % more preferably less than 0.1 wt. % of further components.
Preferably the aqueous carrier is suitable for use as a carrier for a home or personal care product. Preferred personal care products include shampoos, hair conditioners, deodorants, skin cleansing compositions and oral care products such as toothpastes and mouthwashes. Preferred home care products are for example a hard surface cleaner or laundry composition.
The antimicrobial additive composition according to the invention can be used as an antimicrobial raw material where it would be diluted in a further composition or the composition may be a consumer product the application of which is intended to provide antimicrobial effect to a substrate or even as a preservative when added to a consumer composition.
Preferably the lactam is of formula (I) or (II):
Preferably the lactam is of formula (I) or (II) wherein:
R1 and R2 are each independently selected from hydrogen, halogen, alkyl, cycloalkyl, alkoxy, oxoalkyl, alkenyl, heterocyclyl, heteroaryl, aryl and aralalkyl; and
R3 is selected from hydrogen, hydroxyl, alkyl, cycloalkyl, alkoxy, oxoalkyl, alkenyl, heterocyclyl, heteroaryl, cycloalkyl, aryl, aralalkyl and —C(O)CR6=CH2;
R4 and R5 are independently selected from hydrogen, aryl, heterocyclyl, heteroaryl, and arylalkyl; and
R6 is selected from hydrogen and methyl; and
R7 is selected from hydrogen and —C(O)CR6=CH2; and
Preferably, at least one of R4 and R5 is hydrogen; and
Preferably, at least one of R1 and R2 is selected from hetercyclyl, heteroaryl, aryl and arylalkyl; and
Preferably, R1 is hydrogen. Preferably, R3 is hydrogen. Preferably, R4 is hydrogen. Preferably, R5 is hydrogen. Preferably, R6 is hydrogen; and
Preferably, R2 is aryl or aralalkyl. More preferably, R2 comprises a halogen substituted phenyl group.
Preferably, the hydrotrope is selected from monopropylene glycol, dimethylsulphoxide, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene derivatives of castor oil and ethanol.
Preferably, the hydroptrope is present at from 0.001 to 25% wt. of the composition.
Preferred lactams are:
The most preferred lactams are:
Preferably, the hydrotrope is selected from monopropylene glycol, dimethylsulphoxide, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene derivatives of castor oil and ethanol.
Preferably, the polyoxyethylene sorbitan fatty ester is a monoester selected from monolaurate, monopalmitate, monostearate and monooleate.
Preferably, the polyoxyethylene sorbitan fatty ester comprises from 5 to 80 oxyethylene units, more preferably from 10 to 45 and most preferably 20. Examples include Polysorbates 20, 40, 60 and 80.
The most preferred polyoxyethylene sorbitan fatty ester is Polysorbate 20.
Preferably, the polyoxyethylene derivative of castor oil comprises from 10 to 50 oxyethylene units, more preferably from 30 to 45 and most preferably 40. Examples include PEG-20, 40 and 60 hydrogenated castor oil.
The most preferred polyoxyethylene derivative of castor oil is PEG-40 hydrogenated castor oil.
Preferably, the composition is a home care or personal care product.
Preferred personal care products include shampoos, hair conditioners, deodorants, skin cleansing compositions and oral care products such as toothpastes and mouthwashes. Preferred home care products include a hard surface cleaner or laundry composition.
Lactams
Suitable lactams are disclosed in WO 2007/085042 and WO 2004/016588 the contents of which with particular regard to the manufacture of lactams and from WO 2007/085042 the manufacture of acrylate polymers with certain lactams associated thereto, is incorporated by reference.
For example:
The following data illustrates the antimicrobial efficacy of a laundry composition (hereinafter ‘base composition’) comprising a lactam (Ref. 295 and Ref. Unsubstituted) and a hydroptrope (monopropylene glycol) but only where hydroptrope is mixed with lactam before adding to the remainder of the composition. The test samples were as follows:
Test samples were diluted in sterile water to achieve a 11.5 ppm level of lactam. Dilute solution (80 μl) was added to a S. epidermidis suspension (20 μl) of bacteria at a concentration of 8 logs in a microplate. Growth media (100 μl tryptone soya broth) was added to each well of the microplate and incubated for 20 hours. Bacterial respiration was measured every 30 minutes and the results were:
The results are shown in
The following illustrates the broad application of the invention within the realm of lactams.
The example below is from data obtained when pre-blending lactams with hydrotrope before adding to the remainder of the composition, and diluting to 11.5 ppm and 0.575 ppm in sterile water in order to assess efficacy against S. epidermidis suspension Dilute solution (80 μl) was added to a S. epidermidis suspension (20 μl) of bacteria at a concentration of 8 logs in a microplate. Growth media (100 μl tryptone soya broth) was added to each well of the microplate and incubated for 20 hours. Bacterial respiration was measured every 30 minutes. Data of the test samples were then compared to un-treated cell suspensions (sterile water added instead of test samples) and percent inhibition calculated.
The aim of this example was to investigate methods of achieving solubility of 5-methylene-4-phenyl-1H-pyrrol-2(5H)-one (Ref. unsubstituted) into the following above described base formulation.
An Ultrasonic mixer was used to obtain determine solubility.
We used a Hielscher UP200S (200W) Sonic Tip on batches of 5-20 ml. We sonicated for up to 60 minutes.
The polysorbates and Pegylated castor oil were considered suitable enough to pursue further experimentation.
Further Evaluations with Each Candidate Solubiliser
We then tested the candidate solubilisers with 1% lactam, both with 72 hours high speed magnetic stirring (with held temperature of ˜500 in the cases of solubilisers that solidify alone at room temperature) and also 20 minutes Sonication.
Preparation of the Lactam Solutions
In each case we incorporated the lactam powder into the solubilisers (at the levels indicated in the below table) using high speed stirring to avoid lumps from forming. Once the powder was added, the described mixing method (either continued high speed stirring or Ultrasonic mixing) commenced. In the cases of Sorbitan Oleate and Polysorbate-60, we applied initial heating to approx. 500 to ensure the solubilisers were fully liquid prior to commencing addition of the lactam. Both of these materials are non-flowing at room temperature. PEG-40 Hydrogenated Castor required initial heating to ˜350 to ensure complete fluidity prior to commencing.
Incorporation of the Lactam Solutions into Base
The base sample provided had a 5% ‘gap’ purposely left out as space for the lactam solution to be added. We ensured the lactam solutions were fully uniform through constant mechanical agitation (to avoid the settling of any unsolubilised lactam material) and added them to base using slow speed stirring to incorporate them without generating aeration.
Stability Testing
We conducted stability testing on all test variants that looked positive (i.e. a reasonable proportion of lactam was solubilised). We prepared samples of the test variants in clear plastic jars and placed them at various temperature conditions:
The aim was to observe any difference in colour, viscosity, solubility or general physical stability. The samples were evaluated every day and compared to the
ambient temperature sample to note any changes. All samples were allowed to equilibrate to ambient temperature before being evaluated.
Isopentyldiol
3-Methoxy-3-methyl-1-butanol
Diglycerin
Pentylene Glycol
PEG-60 Hydrogenated Castor Oil
Polysorbate 60
Polysorbate 80
Sisterna SP30-C
Sisterna SP50-C
Sisterna SP70-C
Polysorbate 20
PEG-40 Hydrogenated Castor Oil
Observation and Formulation Rules
Temperature and Colour Change
One of our first observations was the colour change which was visible in all successful (or partially successful) samples. We saw development of a slight amber tinge to the solution when some lactam was starting to become solubilised. This colour change progressed rapidly when samples exceeded 50 C, resulting in a dark brown colour. When the temperature reached 65 C, the dark brown colour was virtually opaque*. *This level of temperature was only tested for the Polysorbate-20 and PEG-40 Hydrogenated Castor Oil variants.
From observations throughout the project, we concluded that ˜50 C was the optimum temperature for solubilising the lactam.
Mixing Conditions
Very long periods of mechanical stirring (48-72 hours) resulted in improvements in solubilisation compared to shorter periods; however we did not find this length of mixing to be sufficient for full solubilisation. Ultrasonic mixing did prove to be far more successful and we concluded would be required for effective solubilisation, certainly with the shortlisted Polysorbate-20 and PEG-40 Hydrogenated Castor Oil candidates.
From all of the trials conducted, we believe with the right Ultrasonic mixing conditions (of energy versus batch size versus controlled max. 50 C temperature), efficient solubilisation could be achieved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13153600 | Feb 2013 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2014/051731 | 1/29/2014 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2014/118240 | 8/7/2014 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5266590 | Narayanan | Nov 1993 | A |
| 5369118 | Reizlein et al. | Nov 1994 | A |
| 20080095863 | Kabra | Apr 2008 | A1 |
| 20130237613 | Kim | Sep 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 1688543 | Oct 2005 | CN |
| 3910921 | May 1990 | DE |
| 2404502 | Jan 2012 | EP |
| 20100068265 | Jun 2010 | KR |
| WO9213454 | Aug 1992 | WO |
| WO9827811 | Jul 1998 | WO |
| WO9919256 | Apr 1999 | WO |
| WO2004016588 | Feb 2004 | WO |
| WO2007085042 | Aug 2007 | WO |
| WO2008052031 | May 2008 | WO |
| WO 2010069742 | Jun 2010 | WO |
| Entry |
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| Mar. 4, 2014, Search Report in PCTEP2014051731 (NPL 1, pp. 1-5). |
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| Number | Date | Country | |
|---|---|---|---|
| 20150351393 A1 | Dec 2015 | US |
