Lactam compositions and uses

Abstract

The present invention relates to a composition comprising: (a) 0.0001 - 5 wt.% of a lactam; and (b) 1 - 80 wt.% of a solvent; wherein the composition has a pH of 4 to 6.50; wherein the lactam is selected from the group consisting of the following formulae. The present invention also relates to a method of treating a surface to improve the resistance of the surface to bacterial soiling; and also to the use of the combination of a solvent with a pH of 4 to 6.50 applied to the composition in a lactam composition to improve the solubility and stability of the lactam in the composition.

Description

Technical Field

[0001] This invention relates to improvements in the field of hygiene, and particularly to compositions comprising lactams that exhibit improved lactam solubility and stability. Background Technology

[0002] Hygiene, especially the inhibition of bacterial species, is important to consumers.

[0003] Lactams are known as inhibitors of bacterial species. They can be applied to surfaces to inhibit bacterial species.

[0004] The goal is to improve the availability of lactams and provide formulations that exhibit improved lactam solubility and stability. Summary of the Invention

[0005] We have found that by formulating compositions containing lactams in combination with solvents at pH 4–6.50, the resulting formulations exhibit improved lactam solubility and stability.

[0006] In a first aspect, the present invention relates to a composition comprising: -

[0007] (a) 0.0001-5% by weight, preferably 0.0001-2.5% by weight, more preferably 0.0001-1% by weight, even more preferably 0.001-1% by weight of lactam; and

[0008] (b) 0.5-95% by weight, preferably 0.5-90% by weight, more preferably 0.5-80% by weight of solvent;

[0009] The composition has a pH of 4-6.50, preferably pH 4-6.25, and more preferably pH 4.50-6.00;

[0010] The lactams mentioned above are selected from:

[0011] as well as

[0012] Preferably, the pH is 4-5.40, more preferably 4.50-5.40.

[0013] More preferably, the lactam is selected from:

[0014] and / or

[0015] Most preferably, the lactam is:

[0016] (4-Chlorophenyl)-5-methylene-pyrrole-2-one.

[0017] Preferably, the lactam is delivered from the water-based composition, preferably containing 0.1 to 98% by weight, more preferably 0.5 to 80% by weight, and more preferably 1 to 75% by weight of water.

[0018] The solvent is selected from: alcohols; levulinate derivatives; lactate derivatives; and solvents with a dielectric constant of 15 or higher, preferably selected from: alcohols, levulinate derivatives; and lactate derivatives; more preferably selected from: levulinate derivatives and lactate derivatives.

[0019] Preferred examples of solvents are: alcohols, preferably C1-C4 alcohols, more preferably ethanol; lactate derivatives, preferably ethyl lactate and / or butyl lactate; levulinate derivatives, preferably 2-methyltetrahydrofuran, ethyl levulinate and / or ethyl levulinate glycerol ketal (LGK); and solvents with a dielectric constant of 15 or higher, preferably dimethyl sulfoxide (DMSO).

[0020] Preferably, the solvent is selected from: ethanol; ethyl lactate, butyl lactate; 2-methyltetrahydrofuran, ethyl levulinate and ethyl levulinate glycerol ketal (LGK), or mixtures thereof.

[0021] Preferably, the solvent is selected from: acetylacetic acid ester derivatives; and lactate ester derivatives.

[0022] Most preferably, the solvent is selected from: ethyl lactate, butyl lactate; 2-methyltetrahydrofuran, ethyl levulinate and ethyl levulinate glycerol ketal (LGK), or mixtures thereof.

[0023] The solvent is present at levels of 0.5-95% by weight, preferably 0.5-90% by weight, more preferably 0.5-80% by weight. The solvent may be present at minimum levels of 0.5% by weight, 0.75% by weight, 1% by weight, 1.5% by weight, 2% by weight, 2.5% by weight, or even 5% by weight. The solvent may be present at maximum levels of 95% by weight, 90% by weight, 85% by weight, 80% by weight, 70% by weight, 60% by weight, 50% by weight, 40% by weight, 30% by weight, 25% by weight, 20% by weight, or even 10% by weight. Any higher level of solvent is intended to be combined with any lower level of solvent.

[0024] Preferably, the composition comprises one or more surfactants. The surfactant may be present at a level of 0.25 to 25% by weight, preferably 0.25 to 20% by weight, more preferably 0.25 to 15% by weight, even more preferably 0.25 to 10% by weight, or even 0.5 to 10% by weight or even 0.5 to 5% by weight.

[0025] The surfactant may be present at a level of 0.25 to 25% by weight, preferably 0.25 to 20% by weight, more preferably 0.25 to 15% by weight, even more preferably 0.25 to 10% by weight, or even 0.5 to 10% by weight or even 0.5 to 5% by weight.

[0026] The surfactant is preferably selected from anionic, nonionic, cationic, and / or amphoteric surfactants. Nonionic surfactants are preferred.

[0027] The composition preferably contains a buffer.

[0028] In a second aspect, the present invention relates to a method for treating a surface by treating it with a composition according to a first aspect of the invention to improve the surface’s resistance to bacterial contamination.

[0029] Preferably, the surface to be treated is selected from plastics, metals, wood, polymers, paper, fabrics and / or wiping materials.

[0030] Preferably, in this method, the lactam is selected from:

[0031] and / or Preferably

[0032] In a third aspect, the invention also relates to the use of a solvent in a lactam composition and a pH of 4-6.5, preferably 4-6.25, more preferably 4.50-6.00 applied to the composition for improving the solubility and stability of the lactam in the composition.

[0033] Preferably, in the said use, the lactam is selected from:

[0034] and / or Preferably Attached Figure Description

[0035] Figure 1 Figure 1 These are photographs showing the solubility of lactam 488 at pH 5, pH 7, and pH 8.

[0036] Figure 2 Figure 2 The effect of pH on the solubility and stability of lactam 488 is shown. Initial solubility (left axis and circular data points) and stability (right axis and square data points) of lactam vs. buffer pH, where lactam is delivered in ethanol, with a total of 2% solvent and 100 ppm lactam in solution. Detailed Implementation

[0037] Unless otherwise stated, the indefinite article “a” or “one” and its corresponding definite article “the” as used herein refer to at least one, or one or more.

[0038] It should be understood that, unless otherwise explicitly stated, all preferred options are combinable.

[0039] lactam

[0040] Lactams are cyclic amides. The lactam is selected from the following lactams:

[0041]

[0042] More preferably, the lactam is selected from:

[0043] and / or

[0044] Most preferably, the lactam is:

[0045] (4-Chlorophenyl)-5-methylene-pyrrole-2-one.

[0046] When the lactam is cationic, it can be used as a cationic ion or in combination with a suitable counterion (e.g., iodide ion).

[0047] lactam levels

[0048] Preferably, the lactam is present at a level of 0.0001-2.5% by weight, more preferably 0.0001-1% by weight. For example, the lactam may suitably be present at a level of 0.001 to 1% by weight, or even 0.01 to 1% by weight, or even 0.01 to 0.5% by weight.

[0049] Composition

[0050] Preferably, the lactam is delivered from the water-based composition, which preferably contains 0.1 to 98% by weight, more preferably 0.5 to 80% by weight, and even more preferably 1 to 75% by weight of water. The composition may contain any amount of water ranging from a lower amount of 0.1, 0.5, 1, 1.5, 2 or even 5% by weight to up to 30, 40, 50, 60, 70, 75, 80, 85, 90, 95, 96, 97, 98 or even 99% by weight.

[0051] solvent

[0052] The composition contains a solvent.

[0053] Preferred solvents are selected from: alcohols; levulinate derivatives; lactate derivatives; and solvents with a dielectric constant of 15 or higher. Preferred examples of solvents are: alcohols, preferably C1-C4 alcohols, more preferably ethanol; lactate derivatives, preferably ethyl lactate and / or butyl lactate; levulinate derivatives, preferably 2-methyltetrahydrofuran, ethyl levulinate and / or ethyl levulinate glycerol ketal (LGK); and solvents with a dielectric constant of 15 or higher, preferably dimethyl sulfoxide (DMSO).

[0054] Preferably, the solvent is selected from: ethanol; ethyl lactate, butyl lactate; 2-methyltetrahydrofuran (2Me-THF), ethyl levulinate and ethyl levulinate glycerol ketal (LGK), or mixtures thereof.

[0055] Preferably, the solvent is selected from: acetylacetic acid ester derivatives; and lactate ester derivatives.

[0056] Most preferably, the solvent is selected from: ethyl lactate, butyl lactate; 2-methyltetrahydrofuran, ethyl levulinate and ethyl levulinate glycerol ketal (LGK), or mixtures thereof.

[0057] 2Me-THF, ethyl levulinate, and LGK can be classified as levulinic acid derivatives (or levulinic acid ester derivatives). Leucylpropionic acid can be derived from lignocellulosic biomass (i.e., corn husks, sugarcane bagasse, etc.) and can be converted to 2Me-THF in a cyclization reaction, to ethyl levulinate in a one-step esterification, and to LGK in two steps (esterification and ketal synthesis).

[0058] Ethyl lactate and butyl lactate are lactic acid (lactate) derivatives. Lactic acid is a byproduct of fermentation, which then reacts with ethanol or butanol to produce ethyl lactate and butyl lactate.

[0059] The solvent is present at levels of 0.5-95% by weight, preferably 0.5-90% by weight, more preferably 0.5-80% by weight. The solvent may be present at minimum levels of 0.5% by weight, 0.75% by weight, 1% by weight, 1.5% by weight, 2% by weight, 2.5% by weight, or even 5% by weight. The solvent may be present at maximum levels of 95% by weight, 90% by weight, 85% by weight, 80% by weight, 70% by weight, 60% by weight, 50% by weight, 40% by weight, 30% by weight, 25% by weight, 20% by weight, or even 10% by weight. Any higher level of solvent is intended to be combined with any lower level of solvent.

[0060] The solvent may be present at a level of 1-80% by weight, preferably 1-50% by weight, more preferably 1-40% by weight. The solvent level may also be 1-30% by weight, 1-20% by weight, or even 1-15% by weight or 1-10% by weight.

[0061] Preferably, the composition comprises one or more surfactants. The surfactant may be present at a level of 0.25 to 25% by weight, preferably 0.25 to 20% by weight, more preferably 0.25 to 15% by weight, even more preferably 0.25 to 10% by weight, or even 0.5 to 10% by weight or even 0.5 to 5% by weight.

[0062] The surfactant is preferably selected from anionic, nonionic, cationic, and / or amphoteric surfactants. Nonionic surfactants are preferred.

[0063] The composition may preferably contain a buffer to help maintain any resulting composition within a specified pH range. The buffer system may be any commonly used buffer system known in the art. These may include, for example, citrate, acetate, phosphate and / or carbonate buffers, or mixtures thereof.

[0064] Further components

[0065] The composition may contain further ingredients such as surfactants, chelating agents, thickeners, pH adjusters, and fragrances.

[0066] The invention will be further described through the following non-limiting embodiments.

[0067] Example

[0068] Example 1 - Preparation of a preferred lactam

[0069] Preparation of 4-(4-chlorophenyl)-5-hydroxy-5-methylfuran-2(5H)-one

[0070]

[0071] 1-(4-chlorophenyl)prop-2-one (40.00 g, 34.75 mL, 237.2 mmol), glyoxylic acid monohydrate (32.75 g, 355.8 mmol), and phosphoric acid (69.74 g, 711.7 mmol) were combined at room temperature and then heated to 85 °C overnight. After cooling to room temperature, the mixture was poured into a mixture of water (500 mL) and ethyl acetate (500 mL). The layers were separated, and the aqueous phase was extracted with ethyl acetate (500 mL). The combined organic layers were washed with a 1:1 mixture of water and brine (2 x 500 mL), dried (MgSO4), and concentrated under reduced pressure to give 4-(4-chlorophenyl)-5-hydroxy-5-methylfuran-2(5H)-one (66.00 g, >100% yield), which was a brown oil. This substance was used for the next step without further purification.

[0072] Preparation of 4-(4-chlorophenyl)-5-hydroxy-5-methyl-1H-pyrrole-2(5H)-one

[0073]

[0074] 4-(4-chlorophenyl)-5-hydroxy-5-methylfuran-2(5H)-one (66.00 g, 293.8 mmol) was dissolved in thionyl chloride (196.8 g, 120.0 mL, 1654 mmol) and heated at 40 °C for 1 hour, followed by heating at 80 °C for 2 hours. The mixture was concentrated under reduced pressure and azeotropically reacted with 2-methyltetrahydrofuran (200 mL). The residue was diluted with 2-methyltetrahydrofuran (160 mL) and the solution was added at 0 °C to a cooled, stirred mixture of 28% ammonia (180 mL) in 2-methyltetrahydrofuran (20 mL). The mixture was warmed to room temperature and stirred overnight. Water (100 mL) and ethyl acetate (200 mL) were added, and the layers were separated. The aqueous phase was extracted with ethyl acetate (200 mL), and the combined organic extracts were dried (MgSO4) and concentrated under reduced pressure. 4-(4-chlorophenyl)-5-hydroxy-5-methyl-1H-pyrrole-2(5H)-one (23.18 g, 35% yield) was purified by dry rapid column chromatography (5-60% ethyl acetate in heptane) as a cream-colored solid.

[0075] 1 H NMR(400MHz,d6-DMSO)8.55(brs,1H),7.88-7.83(m,2H),7.51-7.46(m,2H),6.37(d,1H),6.32(s,1H),1.45(s,3H)

[0076] UPLC (alkaline) 1.5 L / 5.00 min, 100% purity, M+H + 224

[0077] MP 177℃

[0078] Preparation of 4-(4-chlorophenyl)-5-methylene-1H-pyrrole-2(5H)-one

[0079]

[0080] A solution of boron trifluoride diethyl ether compound (8.213 g, 7.142 mL, 57.87 mmol) in anhydrous dichloromethane (45 mL) was added to a cooled solution of 4-(4-chlorophenyl)-5-hydroxy-5-methyl-1H-pyrrole-2(5H)-one (10.00 g, 44.51 mmol) in anhydrous dichloromethane (100 mL) for 15 minutes at 0 °C. The mixture was stirred at 0 °C, then slowly heated to room temperature and stirred for 2 hours. The reaction was quenched with ice water (100 mL) and the layers were separated. The aqueous layer was extracted with dichloromethane (100 mL), and the combined organic layers were washed with a 1:1 mixture of water and saturated sodium bicarbonate aqueous solution (100 mL), dried (MgSO4), and filtered. Silica was added to the filtrate and the mixture was stirred for 10 minutes. The mixture was then filtered through a silica plug, thoroughly washed with dichloromethane, and then washed with a 3:1 mixture of dichloromethane and diethyl ether. Fractions containing the desired product were combined and concentrated under reduced pressure. A precipitate formed during concentration, which was collected by filtration and washed with diethyl ether to give 4-(4-chlorophenyl)-5-methylene-1H-pyrrole-2(5H)-one (5.25 g, 57% yield) as a cream-colored solid.

[0081] 1 H NMR(400MHz,d6-DMSO)10.10(s,1H),7.54-7.47(m,4H),6.36(s,1H),5.04(t,1H),4.85(s,1H)

[0082] UPLC (alkaline) 1.87 / 5.00 min, 100% purity, M+H + 206

[0083] MP 182℃

[0084] Preparation of 5-hydroxy-5-methyl-4-(p-tolyl)furan-2(5H)-one

[0085]

[0086] 1-(p-Tolyl)prop-2-one (25.00 g, 24.00 mL, 168.7 mmol), glyoxylic acid monohydrate (23.29 g, 253.0 mmol), and phosphoric acid (49.60 g, 506.1 mmol) were combined at room temperature and then heated overnight at 90 °C. After cooling to room temperature, the mixture was poured into a stirred mixture of ice water (400 mL) and ethyl acetate (400 mL). The layers were separated, and the organic phase was washed with water (100 mL), dried (MgSO4), and concentrated under reduced pressure. The mixture was azeotropically reacted with 2-methyltetrahydrofuran (50 mL) to give 5-hydroxy-5-methyl-4-(p-Tolyl)furan-2(5H)-one (16.50 g, 48% yield) as a brown solid.

[0087] 1 H NMR(400MHz,d6-DMSO)7.86(s,1H),7.75(d,2H),7.28(d,2H),6.59(s,1H),2.32(s,3H),1.61(s,3H)

[0088] Preparation of 5-hydroxy-5-methyl-4-(p-tolyl)-1H-pyrrole-2(5H)-one

[0089]

[0090] 16.50 g (80.80 mmol) of 5-hydroxy-5-methyl-4-(p-tolyl)furan-2(5H)-one was dissolved in thionyl chloride (48.06 g, 29.47 mL, 404.0 mmol) and heated at 50 °C for 1 hour, followed by heating under reflux for 1 hour. After cooling to room temperature, the mixture was concentrated under reduced pressure and azeotropically reacted with 2-methyltetrahydrofuran (2 x 50 mL). The residue was diluted with 2-methyltetrahydrofuran (60 mL) and the solution was added at 0 °C to a cooled, stirred mixture of 28% ammonia (55 mL, 808.0 mol) in 2-methyltetrahydrofuran (10 mL). The mixture was warmed to room temperature and stirred overnight. 2-methyltetrahydrofuran was removed under reduced pressure, and the residue was diluted with water (200 mL) and diethyl ether (100 mL). The mixture was stirred at room temperature for 20 minutes. The solid was collected by filtration and stirred in water (100 mL) and ether (50 mL) at room temperature for 10 minutes. The solid was collected by filtration, washed with water and ether, and dried under vacuum at 50 °C to give 5-hydroxy-5-methyl-4-(p-tolyl)-1H-pyrrole-2(5H)-one (10.49 g, 31% yield) as a light beige solid.

[0091] 1 H NMR(400MHz,d6-DMSO)8.44(brs,1H),7.73(d,2H),7.21(d,2H),6.24(s,2H),2.29(s,3H),1.45(s,3H)

[0092] 13 C NMR(400MHz,d6-DMSO)170.4(s,1C),161.1(s,1C),139.8(s,1C),129.7(s,2C), 128.9(s,1C),128.2(s,2C),119.1(s,1C),87.8(s,1C),26.7(s,1C),21.5(s,1C)

[0093] UPLC (alkaline) 1.41 / 5.00 min, 100% purity, M+H+ 204

[0094] MP decomposes at 178℃

[0095] Preparation of 5-methylene-4-(p-tolyl)-1H-pyrrole-2(5H)-one

[0096]

[0097] A solution of boron trifluoride diethyl ether compound (6.85 g, 5.96 mL, 55.5 mmol) in anhydrous dichloromethane (40 mL) was added to a cooled solution of 5-hydroxy-5-methyl-4-(p-tolyl)-1H-pyrrole-2(5H)-one (8.68 g, 42.7 mmol) in anhydrous dichloromethane (87 mL) over 15 minutes at 0 °C. After 1 hour, the mixture was slowly heated to room temperature. After another 3 hours, the reaction was diluted with dichloromethane (50 mL) and ice water (100 mL) and stirred for 10 minutes. The layers were separated, and the organic layer was washed with water (100 mL), a 1:1 mixture of water and saturated sodium bicarbonate aqueous solution (100 mL), and brine (100 mL). The organic layer was filtered through diatomaceous earth and washed with dichloromethane. Any excess water was removed by pipetting, and the filtrate (MgSO4) was dried and concentrated under reduced pressure to a brown solid. The solid was stirred in hot dichloromethane (120 mL) for 15 minutes, then slowly cooled to room temperature, and then cooled to 0 °C. The solid was collected by filtration to give 5-methylene-4-(p-tolyl)-1H-pyrrole-2(5H)-one (3.87 g, 49% yield) as a yellow solid. Silica was added to the filtrate, and the mixture was stirred for 10 minutes, then filtered through a silica plug, washed thoroughly with dichloromethane, and then washed with a 4:1 mixture of dichloromethane and diethyl ether. The filtrate was concentrated under reduced pressure to give 5-methylene-4-(p-tolyl)-1H-pyrrole-2(5H)-one (0.58 g, 7%) as a yellow solid. The overall yield of 5-methylene-4-(p-tolyl)-1H-pyrrole-2(5H)-one was 4.45 g, 56% yield.

[0098] 1 H NMR(400MHz,d6-DMSO)10.11(brs,1H),7.35(d,2H),7.25(d,2H),6.25(s,1H),5.01(s,1H),4.85(s,1H),2.31(s,3H)

[0099] UPLC (alkaline) 1.83 / 5.00 min, 100% purity, M+H + 186

[0100] MP decomposes at 200℃

[0101] Materials used

[0102] In the following examples, the lactam used is lactam 488.

[0103] This is 4-(4-chlorophenyl)-5-methylene-pyrrole-2-one and its structure is shown below:

[0104]

[0105] Example 2

[0106] This example demonstrates the effect of pH on the solubility of lactams in an aqueous composition containing a solvent. A target 10,000 ppm stock solution of lactam 488 in ethanol was prepared and placed on a bottle roller for 24 hours, then filtered through a syringe filter to produce a saturated solution (potentially approximately 8,000 ppm in ethanol). This stock solution was mixed in a 1:2 ratio with 0.1 M acetate buffer at pH 5.2 or with 0.1 M phosphate buffer at pH 7 or 8, stirred in a vial, and any precipitate formed was visually observed, indicating insolubility. From Figure 1 (Glass image) It can be seen that lactams are mostly soluble to an acceptable level at pH 5, while the solubility is greatly reduced at pH 7 and 8.

[0107] Example 3

[0108] This example demonstrates that the lactam composition lacks stability at pH levels below 4 and above 6.5.

[0109] The initial lactam solubility (over 3 hours) was measured by preparing a 5 mg / mL solution of lactam 488 in ethanol. A 0.1 M phosphate / citrate / carbonate mixed buffer was prepared and adjusted to a pH range of 2–10 (accurate values ​​within...). Figure 2 (as shown in Table 1), and then add lactam 488 / EtOH stock solution to a total of 2%, corresponding to a theoretical lactam concentration of 100 ppm in the solution.

[0110] The solution was equilibrated for 3 hours, and then 200 μl of each of the seven replicates was aliquoted into 96-well microtiter plates (Greiner, UV-Star), with the eighth well serving as a background without lactam. UV absorption spectra were recorded in the 200–450 nm range using a Varioskan Lux UV / Vis plate reader to quantify the intensity (λ) of the lactam peak. max =280nm), and for calibration of known EtOH / lactam solutions, the signal is converted to ppm lactam in solution.

[0111] Using solution state 1Long-term lactam stability was measured by ¹H NMR. Lactam 488 was dissolved in d6-DMSO to the maximum concentration (~10 mg / mL) and mixed with a series of pH buffers (pH 7.4 0.2 M phosphate buffer, pH 6 0.1 M citrate buffer, pH 5.2 0.1 M acetate buffer, 4, 2) and water in a 2:1 ratio. These samples were then filtered and subjected to water inhibition. 1 ¹H NMR studies were conducted weekly over four weeks. The relative percentage of residual lactam was quantified using the integral of the buffer peak, compared to the lactam resonance at 5.22 ppm.

[0112] The results of the stability and solubility of lactams are in Figure 2 For UV / Vis and 1 H NMR data show. Figure 2 The values ​​are also shown in Table 1.

[0113] 2 >80* 20 3.12 80.53 ～30* 4.08 77.83 50 5.22 73.53 80 6.21 72.22 60 7.08 67.90 20 8.05 67.68 <10* 8.92 68.43 5 9.84 63.17 <5*

[0114] Table 1 shows the initial concentrations calculated using UV / Vis spectroscopy, and the attenuation measured by NMR spectroscopy – values ​​with * were not measured but were estimated by extrapolation from the figures.

[0115] For compositions with pH values ​​between 4 and 6.5, the lactam initially dissolves and exhibits long-term stability (4 weeks). Above this pH, the composition is not sufficiently soluble and is also unstable, while below pH 4, the composition is unstable.

Claims

1. A composition comprising: (a) 0.0001-5% by weight of lactam; and (b) 1 to 80% by weight of a solvent, wherein the solvent is selected from: C1-C4 alcohols, solvents with a dielectric constant of 15 or higher, or mixtures thereof; The composition has a pH of 4 to 5.40; The lactam mentioned above is: 4-(4-Chlorophenyl)-5-methylene-pyrrole-2-one.

2. The composition according to claim 1, wherein the pH is 4.50-5.

40.

3. The composition according to claim 1, wherein the composition comprises 0.0001-2.5% by weight of lactam.

4. The composition according to claim 1, wherein the composition comprises 0.0001-1% by weight of lactam.

5. The composition according to claim 1, wherein the composition comprises 0.001-1% by weight of lactam.

6. The composition according to claim 1, wherein the composition comprises 1 to 50% by weight of a solvent.

7. The composition according to claim 1, wherein the composition comprises 1 to 40% by weight of a solvent.

8. The composition according to any one of claims 1-7, wherein the composition is a water-based composition.

9. The composition according to any one of claims 1-7, wherein the composition comprises 0.1 to 98% by weight of water.

10. The composition according to any one of claims 1-7, wherein the composition comprises 0.5 to 80% by weight of water.

11. The composition according to any one of claims 1-7, wherein the composition comprises 1 to 75% by weight of water.

12. The composition according to any one of claims 1-7, wherein the solvent is a solvent with a dielectric constant of 15 or higher.

13. The composition according to any one of claims 1-7, wherein the solvent is a C1-C4 alcohol.

14. The composition according to claim 13, wherein the alcohol is ethanol.

15. The composition of claim 12, wherein the solvent having a dielectric constant of 15 or higher is dimethyl sulfoxide (DMSO).

16. The composition according to any one of claims 1-7, wherein the solvent is selected from ethanol, dimethyl sulfoxide (DMSO), or mixtures thereof.

17. The composition according to any one of claims 1-7, wherein the composition comprises a buffer system.

18. A method of treating a surface by treating it with a composition according to any one of claims 1 to 17 to improve the surface's resistance to bacterial contamination.

19. The method of claim 18, wherein the surface to be treated is selected from plastics, metals, wood, polymers, paper, fabrics and / or wiping materials.

20. The use of a combination of a solvent and a pH of 4-5.40 applied to the lactam composition for improving the solubility and stability of the lactam in the composition, wherein the solvent is selected from: C1-C4 alcohols, solvents with a dielectric constant of 15 or higher, or mixtures thereof; and wherein the lactam is: 4-(4-Chlorophenyl)-5-methylene-pyrrole-2-one.

21. The use of a combination of a solvent and a pH of 4.50-5.40 applied to the lactam composition for improving the solubility and stability of the lactam in the composition, wherein the solvent is selected from: C1-C4 alcohols, solvents with a dielectric constant of 15 or higher, or mixtures thereof; and wherein the lactam is: 4-(4-Chlorophenyl)-5-methylene-pyrrole-2-one.

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