Debridement Composition

Abstract

The disclosed technology relates to a wound dressing comprising an absorbent layer impregnated or coated with a composition comprising a chelating agent, an amphoteric surfactant, and an anionic surfactant. The invention further relates to methods and uses of the wound dressing.

Claims

1. A wound dressing or debridement tool comprising an absorbent layer impregnated or coated with a composition comprising a chelating agent, an amphoteric surfactant, and an anionic surfactant.

2. The wound dressing or debridement tool of claim 1, wherein the anionic surfactant is present at 0.05 to 1.5 wt %, or 0.1 to 1 wt %, or 0.1 to 0.5 wt %.

3. The wound dressing or debridement tool of claim 1, wherein the anionic surfactant is chosen from a fatty acid or fatty acid salt, a sulphate, a sulphosuccinate, a sarcosine, a sarcosinate, an isethionate, a glutamate, or a taurate.

4. The wound dressing or debridement tool of claim 1, wherein the amphoteric surfactant is present at 0.01 to 1.5 wt %, or 0.02 to 0.8 wt %, or 0.05 to 0.5 wt %.

5. The wound dressing or debridement tool of claim 1, wherein the amphoteric surfactant is chosen from an hydrocarbyl-amphoacetate, alkenyl-amphoacetate, hydrocarbyl -amphodiacetate, alkenyl-amphodiacetate, hydrocarbylampho-propionate, hydrocarbylampho-dipropionate, or hydrocarbylamphohydroxypropyl sultaine, wherein the hydrocarbyl and alkenyl groups contain 6 to 24, or 8 to 24 carbon atoms.

6. The wound dressing or debridement tool of claim 1, wherein the chelating agent is present at 0.01 to 1 wt %, or 0.1 to 0.75 wt %, or 0.1 to 0.5 wt %.

7. The wound dressing or debridement tool of claim 1, wherein the chelating agent is chosen from a hydroxy-carboxylic acid ester or amide acid, or salts thereof, an oxalate, a phosphate, or a salt of ethylenediaminetetra-acetic acid.

8. The wound dressing or debridement tool of claim 1, wherein the composition is impregnated or coated in the wound dressing and comprises: the chelating agent is present at 0.01 to 1 wt %, the anionic surfactant is present at 0.05 to 1.5 wt %, the amphoteric surfactant is present at 0.01 to 1.5 wt %.

9. The wound dressing or debridement tool of claim 1, wherein the composition is impregnated or coated in the wound dressing and comprises: the chelating agent is present at 0.1 to 0.75 wt %, the anionic surfactant is present at or 0.1 to 1 wt %, or the amphoteric surfactant is present at or 0.02 to 0.8 wt %.

10. The wound dressing or debridement tool of claim 1, wherein the composition is impregnated or coated in the wound dressing and comprises: the chelating agent is present at 0.1 to 0.5 wt %, the anionic surfactant is present at 0.1 to 0.5 wt % the amphoteric surfactant is present at or 0.05 to 0.5 wt %.

11. The wound dressing or debridement tool of claim 1, wherein the composition impregnated or coated in the wound dressing or debridement tool comprises: the chelating agent is present at 0.1 to 0.5 wt % (or 0.15 to 1.5 gm.sup.−2), the anionic surfactant is present at 0.1 to 0.5 wt % (or 0.15 to 1.5 gm.sup.−2), and the amphoteric surfactant is present at or 0.05 to 0.4 wt % (or 0.075 to 0.6 gm.sup.−2).

12. The wound dressing or debridement tool of claim 1, wherein the composition impregnated or coated in the wound dressing or debridement tool comprises: the amphoteric surfactant is chosen from an hydrocarbyl-amphoacetate, alkenyl-amphoacetate, hydrocarbyl-amphoacetate, alkenyl-amphoacetate, hydrocarbylampho-propionate, hydrocarbylampho-dipropionate, or hydrocarbylamphohydroxypropyl sultaine, wherein the hydrocarbyl groups contain 6 to 24, or 8 to 24 carbon atoms; the anionic surfactant is chosen from a fatty acid or fatty acid salt, sulphate, a sulphosuccinate, a sarcosine, a sarcosinate, an isethionate, taurate, and a glutamate; and the chelating agent is chosen from a hydroxy-carboxylic acid ester or amide acid, or salts thereof (for example a citrate, tartrate, tartramide, or tartrimide, gluconic acid, a gluconate, a lactate, lactic acid, glycolic acid, or glycolate), an oxalate, a phosphate, or a salt of ethylenediaminetetra-acetic acid (EDTA).

13. The wound dressing or debridement tool of claim 1, wherein the composition impregnated or coated in the wound dressing comprises: the amphoteric surfactant is chosen from an hydrocarbyl-amphoacetate, alkenyl-amphoacetate, hydrocarbyl-amphoacetate, alkenyl-amphoacetate, hydrocarbylampho-propionate, hydrocarbylampho-dipropionate, or hydrocarbylamphohydroxypropyl sultaine, wherein the hydrocarbyl groups contain 6 to 24, or 8 to 24 carbon atoms; the anionic surfactant is chosen from a fatty acid or fatty acid salt, a glutamate, a sulphosuccinate, a sarcosine, or a sarcosinate; and the chelating agent is chosen from an oxalate, a citrate, a phosphate, or a salt of EDTA.

14. The wound dressing or debridement tool of claim 1, wherein the composition may be impregnated or coated in the wound dressing further comprises: a nonionic surfactant.

15. The wound dressing of claim 14, wherein the nonionic surfactant is present at 0.01 to 0.7 wt % (or 0.015 to 1.05 gm.sup.−2), or 0.05 to 0.5 wt % (or 0.075 to 0.75 gm.sup.−2), or 0.1 to 0.3 wt % (or 0.15 to 0.45 gm.sup.−2).

16. The wound dressing or debridement tool of claim 1, wherein the composition impregnated or coated in the wound dressing or debridement tool comprises: the chelating agent is present at 0.01 to 1 wt % (or 0.015 to 1.5 gm.sup.−2), the anionic surfactant is present at 0.05 to 1.5 wt % (or 0.075 to 2.25 gm.sup.−2), the amphoteric surfactant is present at 0.01 to 1.5 wt % (or 0.015 to 2.25 gm.sup.−2), and the nonionic surfactant may be present at 0.01 to 0.7 wt % (or 0.015 to 1.05 gm.sup.−2).

17. The wound dressing or debridement tool of claim 14, wherein the nonionic surfactant is chosen from polyoxyethylene fatty acid esters (polyoxyethylene sorbitan fatty acid ester), polyoxyethylene glycol fatty acid esters (polyoxyethylene glycol fatty acid ester), sucrose fatty acid esters (sucrose fatty acid ester), poly oxyethylene hydrogen carbonate castor oils and polyoxyethylene alkyl ethers (polyoxyethylene hydrogenated castor oil) ether (polyoxyethylene alkyl ether).

18. The wound dressing or debridement tool of claim 1, wherein the absorbent layer impregnated or coated with the composing comprises at least one layer composed of a foam, absorbent, or a gel-forming fibre.

19. The wound dressing or debridement tool of claim 1, wherein the wound dressing absorbent layer is a gel-forming fibre.

20. The wound dressing or debridement tool of claim 1, wherein the wound dressing absorbent layer is a gel-forming fibre. And the fibre is chemically modified carboxymethylcellulose fibres, typically sodium carboxymethylcellulose fibres.

21. (canceled)

22. (canceled)

23. (canceled)

24. (canceled)

25. (canceled)

26. A composition comprising a chelating agent, an amphoteric surfactant, and an anionic surfactant for use in the treatment of a wound, such as a chronic wound, acute wound, burn, a wound comprising a bacterial biofilm or a wound comprising slough.

27. (canceled)

Description

DETAILED DESCRIPTION OF THE DISCLOSURE

[0121] As used herein the expression “wound” may include an injury to living tissue and may be caused by a cut, blow, or other impact, abrasion, pressure, heat or chemical; typically, one in which the skin is cut or broken. A wound may often be described as chronic or acute. Acute wounds may occur as a result of surgery or trauma. Typically, when not too severe and where the victim is otherwise in good health, wounds progress through well-defined stages of healing within a predicted timeframe. Chronic wounds begin as acute wounds. An acute wound can become a chronic wound when it does not follow the normal healing pathway resulting in a lengthened recovery. It is believed that the transition from acute to chronic wound can be due to an inadequate immune response for example: the patient being immuno-compromised, the wound being insufficiently perfused or being highly contaminated.

[0122] Chronic wounds may include for example: venous ulcers (such as those that occur in the legs due to venous insufficiency), which account for the majority of chronic wounds and mostly affect the elderly; diabetic ulcers (for example, foot or ankle ulcers); arterial ulcers (due to peripheral arterial disease); and pressure injuries due to immobility.

[0123] Wounds may also include a deep tissue injury. Deep tissue injury is a term proposed by the National Pressure Ulcer Advisory Panel (NPUAP) to describe a unique form of pressure ulcers. These ulcers have been described by clinicians for many years with terms such as purple pressure ulcers, ulcers that are likely to deteriorate and bruises on bony prominences.

[0124] The disclosed technology relates to the subject matter as defined above. The term “slough” is known to the skilled person and may be defined as a layer or mass of dead tissue separated from surrounding living tissue, or tissue that is adhered to a wound but capable of being removed as in a wound, sore, or inflammation.

Wound Dressing

[0125] The wound dressing disclosed herein may have a thickness between 0.5 to 20, or 2 to 10, or 3 to 7 mm.

[0126] In one embodiment the wound dressing may be buffered to have a pH of 4-10, or 5-8, or 5.5-6.5.

[0127] The wound dressing may be comprised of one or more layers selected from the group comprising an outer cover layer, an absorbent layer, a gel-forming fibre, an adhesive layer, a wound contact layer, a distribution layer, and combinations thereof.

[0128] In some embodiments, a wound dressing includes one or more absorbent layer(s). The absorbent layer may be a foam or a structure derived from a superabsorbent polymeric material. If foam is used, the foam may also act as a distribution layer.

[0129] In some embodiments the wound dressing comprises an outer cover layer and one or more absorbent layer(s) in combination with a gel-forming fibre. The gel-forming fibre typically is in direct contact with the wound, and thus no additional wound contact layer is required.

[0130] By gel forming fibres is meant hygroscopic fibres which upon the uptake of wound exudate become moist slippery or gelatinous. The gel forming fibres can be of the type which retain their structural integrity on absorption of exudate or can be of the type which lose their fibrous form and become an amorphous or structureless gel. The gel forming fibres are typically sodium carboxymethylcellulose fibres, chemically modified cellulosic fibres, alkyl sulphonate modified cellulosic fibres such as those described in WO2012/061225, pectin fibres, alginate fibres, chitosan fibres, hyaluronic acid fibres, or other polysaccharide fibres or fibres derived from gums, as well as non-cellulose synthetic fibres such as poly(vinyl alcohol) and polyacrylate.

[0131] In one embodiment the gel forming fibres may be chemically modified carboxymethylcellulose fibres, typically sodium carboxymethylcellulose fibres. In one particular embodiment the absorbent layer is the gel-forming fibres, and the dressing does not contain additional dressing layers.

[0132] The gel forming fibres are typically chemically modified cellulosic fibres in the form of a fabric and in particular carboxymethylated cellulose fibres as described in PCT WO00/01425. Sodium carboxymethylcellulose fibres typically have a degree of substitution of at least 0.05 carboxymethyl groups per glucose unit. The gel forming fibres typically have an absorbency of at least 2 grams (or at least 8 grams, or at least 10 grams), 0.9% saline solution per gram of fibre (as measured by BS EN 13726-1 (2002) “Test methods for primary wound dressings”, section 3.2 “Free swell absorptive capacity”). The carboxymethylated cellulosic fabrics typically have a degree of substitution between 0.12 to 0.35 (as defined in WO00/01425) more typically a degree of substitution of between 0.20 and 0.30 such that the absorbency of a fabric produced from is increased when compared to the unmodified cellulose. Particular useful fabrics have an absorbency of between 10 g/g of to 30 g/g of isotonic aqueous solution as measured by the method described in BS EN 13726-1 (2002).

[0133] The cellulosic fabric typically consists solely of cellulosic fibre but may contain a proportion of a textile fibre or gel forming fibre. This textile fibre may be for example a cellulose fibre of a known kind and may comprise continuous filament yarn and/or staple fibre.

[0134] The absorbent layer can be in direct contact with the wound, or comprise a wound contact layer, positioned between the wound and the absorbent layer. The wound contact layer is capable of absorbing exudate from the wound and transmitting it to the absorbent layer.

[0135] The wound contact layer in one embodiment comprises gel-forming fibres, or a silicone gel.

[0136] The outer cover layer of the dressing is a bacterial and viral barrier layer which typically resists the ingress of liquid but allows moisture vapour transmission.

[0137] In one embodiment the absorbent layer may be a superabsorbent. The superabsorbent may be a fibrous polymer, or a nonwoven material.

[0138] The superabsorbent may be a polyacrylate or starch polymer.

[0139] In one embodiment the absorbent layer may be a foam. The foam may have an open cell and/or closed cell structure. The foam may be derived from polyurethane, polyvinyl alcohol, a collagen, a chitosan. Typically, the foam may be a polyurethane foam.

[0140] The wound dressing disclosed herein may be prepared by a process comprising applying to the absorbent layer a composition comprising a chelating agent, an amphoteric surfactant as disclosed herein.

[0141] Inclusion of the disclosed technology in a wound dressing or similar wound treatment device (for instance a debridement tool) can be achieved by addition to the material from which the device is constructed or by addition to the finished device.

[0142] For example, where a component part or all of the device is constructed from fibres the technology may be: [0143] added to the dope (the liquid from which the fibres are spun [extruded]) [0144] co-extruded in a hot melt process [0145] washed into the fibre by a soaking process [0146] coated onto the formed fibre by passing through a bath containing the technology in a liquid or solution form {where the solute may be removed by a drying process (known in the art—such as by forced air (or any other gas—particularly nitrogen if flammable solvents are involved; or by heat; or by heat and forced air)} or as a molten liquid [0147] sprayed onto the formed fibre in a liquid form or from a solution {where the solute may be removed by a drying process (known in the art—such as by forced air (or any other gas—particularly nitrogen if flammable solvents are involved; or by heat; or by heat and forced air)} or as a molten liquid in a hot-melt inkjet process [0148] added as a powder coating where adhesion could be encouraged by electrostatic effects or by increasing the adhesive tack properties of the receiving fibre (say by partial hydration using humidity or by pre-treating the fibre with a viscous liquid such as an alcohol (for example hexanol), a polyol (for example propan-1,2-diol or glycerol), a hydrophilic hydrocarbon (for example a poly(ethylene oxide)) or by the order of addition of the invention itself (for example a liquid surfactant such as liquid fatty acid or fatty acid salt or a liquid fatty acid that will form the salt in situ). Or, where the device is preformed, for example as a fabric or a foam, the technology may be added via similar washing, coating, spraying or powder coating. [0149] Additionally, the technology may be added by suspending the technology in a non-solvent and passing this through the device such that the suspended technology is mechanically trapped (i.e. positively added by filtration of the technology); [0150] or added as an ink or pigment by a printing process, for example a screen-printing process, where the addition can be closely controlled by use of the screen. The print could be a continuous, for example as achieved by flood-coating, or, more preferably as a discontinuous coating (regular or random patterned) as it has less impact on the devices porosity/breathability, flexibility and ability to contour to the complex topography of the wound bed and both the macroscopic (physiology) and microscopic (cellular) levels. [0151] added as a separate layer: [0152] for example, as a gel coating directly onto the wound device by, for example, a knife-over-roll or gravure coating technique [0153] or cast as a film by a similar coating technique and then adhered to the wound device by tackifying the device or the film by, for example humidification, or by the addition of an adhesive.

[0154] While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.

EXAMPLE 1

[0155] The following examples are prepared and evaluated using a simulated wound matrix composition. A wound matrix is prepared to contain:

TABLE-US-00001 Component Formulation Water 44.338% w/w Sodium alginate 1.75% w/w Xanthan Gum 25.2% w/w Microcrystalline Cellulose 0.3% w/w Electrolytes and divalent Calcium chloride (1.5% w/w) metal ions Hydrolysed Collagen 1% w/w Hydrolysed Keratin 1% w/w Gelatin type A 0.5% w/w Human Plasma 3% w/w Deactivated yeast cells 20% w/w Crystal Violet Stain 0.26% w/w solution used at 2.5% w/w of final formulation Sodium propylparaben 0.112% w/w Sodium hydroxide 0.3% w/w

[0156] The simulated wound matrix is crosslinked with 1.5% w/w calcium chloride for 18 hours onto a solid phase screening system (96-peg microtiter plate lid). The pegs are dipped into the simulated wound matrix and immediately transferred to a calcium chloride bath to achieve cross-linking. Solutions of test materials are prepared at 1% w/w in a 96 well microtiter plate. Following crosslinking, the pegs are inserted into the wells and incubated at 37° C. for 1 hour. Efficacy is characterised by the change in colour of the test solutions resulting from disruption of the stained material and is quantified by reading the absorbance of each solution at 595 nm. Results are presented with respect to a 1% w/w benzethonium chloride aqueous solution. Benzethonium chloride being a Comparative Example and disclosed in s WO2012/136968 as part of the invention disclosed therein.

TABLE-US-00002 1% w/w Surfactants % Difference in HLB Compound Class Efficacy Value† Benzalkoniunn Cationic +60 N/A Chloride Di-sodium Lauryl Anionic +844 N/A Sulfosuccinate Sodium Laureth-2 Anionic −30 15.3 Sulphate Sodium Dodecyl Anionic −99 33.0 Sulphate Sodium Oleate Anionic +996 10.55 Cocoamidopropyl Amphoteric +120 N/A betaine Poloxamer 188 Nonionic −90 3.4 1% w/w Chelators % Difference Solubility of in Calcium Salt Compound Efficacy (mg/mL) Tris-odium Citrate +1750 0.23 (pH 7.5) Potassium Oxalate +1350 <0.005 (pH 7.5)  Sodium Di-hydrogen −70 0.63 (pH 4.5) Phosphate Citric Acid +50   17 (pH 2.0) †AKZO Nobel published values using modified Davies HLB group numbers (Cosmetic Emulsions, Elżbieta Sikora, ISBN / ISSN: 978-83-65991-50-8) ‡Determination of calcium salt solubility with changes in pH and .sub.PCO.sub.2, simulating varying gastrointestinal environments. Goss SL et al. Journal of Pharmacy and Pharmacology 59; 11; 1485-1492.

[0157] Comparisons are also made to a composition containing 0.39% w/w di-sodium EDTA and 0.135% w/w benzethonium chloride, based on the formula of a commercially available product (AQUACEL® Ag+Extra)). This composition is 30% less effective than the Comparative example outlined above with 1% benzethonium chloride.

Interpretation of Results

[0158] HLB value is predictive of the efficacy of detergency of certain surfactants and would typically be used to guide selection, the higher the HLB value the greater the predicted detergency. The ability of the surfactants (with published HLB values) at 1% w/w to disrupt the simulated test wound matrix does not correlate as might be expected. Sodium lauryl sulphate (SLS) is regularly used as a bench mark for high detergency but is also regarded as being too harsh for routine use in personal care products. Di-sodium lauryl sulfosuccinate is regarded as a milder alternative to SLS. Sodium oleate, the basis for traditional bar-soap, is also generally accepted as being an inferior cleaning agent to SLS, yet both sodium oleate and di-sodium lauryl sulfosuccinate have efficacies an order of magnitude greater than SLS in disrupting the simulated test wound matrix. Similarly, sodium oleate and di-sodium lauryl sulfosuccinate have efficacies an order of magnitude greater than benzalkonium chloride, cocoamidopropyl betaine and Poloxamer™ 188 all of which are commonly used in liquid wound cleansing products. Thus, demonstrating the choice of surfactant cannot be predicted by expected detergency or by selecting components in common use.

[0159] The simulated test wound matrix is cross-linked and fixed onto the test surface by treatment with calcium chloride. It may therefore seem obvious that this fixation could be reversed by application of a compound that can compete for calcium and remove it, for example by precipitation as a poorly soluble salt. It would seem reasonable to assume that lack of solubility of a calcium chelating agent could be used as a predictor of the ability of that agent to remove calcium from the matrix and therefore be of higher matrix disruptive potential. Calcium citrate (at pH 7.5) is significantly more soluble than calcium oxalate at the same pH, yet citrate shows greater efficacy in the simulated test wound matrix than an equivalent w/w of oxalate. Furthermore, although reducing the pH of the citrate system to that of citric acid does both increase solubility of the calcium salt and decrease matrix disruption as predicted, it is still more effective than the higher pH sodium di-hydrogen phosphate which has a less soluble calcium salt. Thus, selecting a chelant cannot be predicted by calcium salt solubility or by pH effect.

EXAMPLE 2

[0160] The combined effect of surfactants and chelants is investigated when presented as a coating on a wound dressing that gels in the presence of water [AQUACEL® Extra, ConvaTec PLC]. Dressings without surfactant or chelator are used as controls.

[0161] The test model from Example 1 is adapted to accommodate solid test materials. To achieve this the simulated wound matrix is cast onto cellulose acetate sheets using a thin film applicator (1.5 mm wet thickness) and submerged face-down into 1.5% w/w calcium chloride for 24 hours. Test dressings are cut to 2 cm.sup.2, hydrated with 1 ml Test Solution A (BS EN 13726-1:2002), placed onto the substrate and incubated 37° C. for 18 hours. Efficacy is characterised by the change in colour of the dressings resulting from absorption of liquified test matrix containing crystal violet dye. The solubilised fraction is quantified by extraction of the crystal violet stain from the dressings by adding 2 ml of 33% v/v acetic acid and extracting for 30 minutes on a roller mixer. The absorbance of each resultant solution is read at 595 nm.

Results on a % w/w basis:

TABLE-US-00003 Increase in Efficacy Experiment Surfactant Chelator % 2A 0.5% w/w 0.25% w/w 275 sodium oleate tetra-sodium EDTA 2B 0.5% w/w  0.5% w/w 244 sodium oleate tetra-sodium EDTA 2C 1.0% w/w  0.5% w/w 264 sodium oleate tetra-sodium EDTA
Results on a weight per unit area basis:

TABLE-US-00004 Increase in Efficacy Experiment Surfactant Chelator % 2A 0.75 g/m.sup.2 0.375 g/m.sup.2 275 sodium oleate tetra-sodium EDTA 2B 0.75 g/m.sup.2  0.75 g/m.sup.2 244 sodium oleate tetra-sodium EDTA 2C  1.5 g/m.sup.2  0.75 g/m.sup.2 264 sodium oleate tetra-sodium EDTA

Interpretation of Results

[0162] Test substances are described as a weight percentage of the dry dressing. As the dressings in the example absorb high volumes of aqueous liquids (approximately 23 g/g in this instance) and the function of the test substances is facilitated by moisture, due consideration must be given to dilution effects. 1.0% w/w in this example approximates to a 0.043% solution if tested as in Example 1. Therefore, much reduced effects might be anticipated. However, significant improvement is achieved over both the control and the cationic surfactant/chelator comparators.

[0163] No improvement in performance is observed for the individual or combined increase in concentration of the test substances.

EXAMPLE 3

[0164] As with any medical treatment, patient safety is paramount and where skin is broken there is always a risk that components may remove essential lipids from tissue, absorbed into local tissue or the circulatory systems of the blood and lymph. To reduce risk, it is advisable to select the safest candidate and to minimise exposure to any soluble or absorbable substance and this is most readily achieved by minimising the amount and/or concentration applied. Because of their comparatively high detergency, anionic surfactants are considered harsh whereas amphoteric surfactants are generally less effective but have better skin compatibility. Therefore, three added component systems on gelling dressings are investigated consisting of a chelator and two surfactants. The test is as described in Example 2.

Results on a % w/w basis:

TABLE-US-00005 Sodium Tetra- Increase Sodium Cocoampho- sodium in Oleate / acetate / EDTA / Efficacy / Experiment % w/w % w/w % w/w % 3A 0.55 0.2625 0.30 57 3B 1.00 0.025 0.50 81 3C 0.10 0.50 0.10 73 3D 0.50 0.0625 0.25 177

[0165] Results on a weight per unit area basis:

TABLE-US-00006 Sodium Tetra- Increase Sodium Cocoampho- sodium in Oleate / acetate / EDTA / Efficacy / Experiment g/m.sup.2 g/m.sup.2 g/m.sup.2 % 3A 0.825 0.394 0.45 57 3B 1.5 0.0375 0.75 81 3C 0.15 0.75 0.15 73 3D 0.75 0.0938 0.375 177

[0166] Interpretation of Results

[0167] No linear relationships between component concentration and activity could be identified with the addition of the amphoteric surfactant (sodium cocoamphoacetate) seemingly reducing activity (comparing example 3B to 2C). However synergistic combinations are found (example 3D) where an addition of the amphoteric surfactant enabled significant reductions in both the anionic surfactant and chelator whilst still achieving a significant improvement in performance over the base dressing.

[0168] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or steps are included or are to be performed in any particular embodiment.

[0169] In this specification, the use of the singular includes the plural unless the context clearly dictates otherwise. In this application, the use of “or” means “and/or” unless stated otherwise. Furthermore, use of the term “including” as well as other forms, such as “include”, “includes,” and “included,” is not limiting.

[0170] Unless defined otherwise, all technical and scientific terms used in this specification have the same meaning as is commonly understood by the reader skilled in the art to which the claimed subject matter belongs. It is to be understood that the foregoing summary of the disclosure and the following examples are exemplary and explanatory only and are not restrictive of any subject matter claimed.

[0171] Each of the documents referred to above is incorporated herein by reference. Except in Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, device dimension, and the like, are to be understood as modified by the word “about.”

[0172] Unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade.

[0173] Each of the documents referred to above is incorporated herein by reference. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word “about”.

[0174] As used herein, the expression “consisting essentially of” permits the inclusion of substances that do not materially affect the basic and novel characteristics of the composition under consideration.

[0175] It is to be understood that at least some of the figures and descriptions of the disclosure have been simplified to focus on elements that are relevant for a clear understanding of the disclosure, while eliminating, for purposes of clarity, other elements that the reader skilled in the art will appreciate may also be required. Because such elements are well known to the reader skilled in the art, and because they do not necessarily facilitate a better understanding of the disclosure, a description of such elements is not provided herein.