Wound cleansing composition

Abstract

78 Abstract The present disclosure relates generally to wound care, and more particularly, to compositions suitable for use in wound care.

Description

Wound cleansing compositionFIELD

[0001] The present disclosure relates generally to wound care, and more particularly, to compositions suitable for use in wound care.BACKGROUND

[0002] Owing to an aging population and growing prevalence of vasculopathy, the incidence of chronic wounds is increasing worldwide. Chronic wounds are a major burden on healthcare systems and patient quality of life, often leading to loss of function and amputation. Although their treatment accounts for approximately 3% of total healthcare costs in developed countries, a 2018 cohort study found that fewer than 50% of chronic wounds managed by the UK National Health Service healed within a year. Moreover, chronic wounds recur in up to 60-70% of patients. This poor prognosis underlines the need for new approaches to chronic wound care.

[0003] Normal wound healing comprises four intricate and overlapping phases: haemostasis, inflammation, proliferation, and remodelling. After the formation of a thrombus, leukocytes infiltrate the wound and remove bacteria and debris, preparing the wound for healing. This enables the formation of new connective tissue and blood vessels, known as granulation tissue, and subsequent wound closure and re-epithelialisation. An wound is classed as chronic if it fails to progress through this sequence within 4-6 weeks. Wound chronicity is often attributed to diabetes and vascular diseases. The resulting nerve damage and poor perfusion to extremities alter the wound microenvironment and delay healing. Chronic wound healing stalls in the inflammatory phase due to an imbalance of cytokines, proteases, and their inhibitors. Prolonged inflammation leads to the accumulation of slough, a fibrinous substance composed of dead leukocytes and degraded proteins.

[0004] Microbial infection occurs in almost all wounds and is a significant cause of chronicity. Bacteria adhere to necrotic tissue in the wound bed and form microcolonies that secrete extracellular polymeric substances (EPS). The bacteria become encased in a EPS matrix which eventually matures into a complex biofilm composed of proteins, polysaccharides, nucleic acids, metal ions, and lipids. Biofilm sequesters antimicrobials and inhibits the activation of phagocytes, providing resistance to both antimicrobials and the host immune system. Moreover, biofilm in the wound bed impedes the migration and function of keratinocytes, leukocytes, and fibroblasts, preventing the normal inflammatory response andsubsequent healing processes. The recalcitrant biofilm perpetuates an inflammatory cycle wherein tissue is degraded more quickly than it is produced, preventing the progression of healing.

[0005] Biofilm is believed to exist in up to 80% of chronic wounds and is a direct cause of wound chronicity. Slough, and other non-viable matter, delays the formation of granulation tissue and facilitates the development of biofilm. It is evident that for any wound to successfully heal, biofilm and necrotic tissue must be removed from the wound bed. Ideal wound management involves the reduction of microorganisms and necrotic tissue to levels that can be managed by the host immune system, without inducing damage to healthy tissues nor bacterial resistance. Standard wound care involves cleansing the wound to remove loosely attached debris and bacteria, followed by the removal of necrotic tissue (debridement), and finally dressing application. Dressings optimise the healing environment by balancing moisture levels, preventing infection, and removing debris. However, wounds should be irrigated between dressing changes to remove any debris and biofilm that may have sloughed off onto the dressing. With little clinical evidence supporting the use of more specialised cleansing materials, normal saline is often used to irrigate wounds due to its high biocompatibility. However, saline is non-antimicrobial and is ineffective at removing biofilm from necrotic wounds. Broad-spectrum antiseptics are frequently used to control wound infection but are often cytotoxic due to their lack of selectivity. Selective antibiotics may be more effective at preserving host tissue, but their repeated use catalyses antibiotic resistance. Moreover, owing to the sequestration properties of EPS, the single use of antimicrobials to combat wound infection has been largely unsuccessful.

[0006] Accordingly, there is a need for wound cleansing solutions having physical modes of action against biofilms and the microorganisms comprised therein. Additionally, there is a need for wound cleansing solutions that exhibit a balance of efficacy and biocompatibility. The present disclosure seeks to address these needs with the various aspects and embodiments defined herein.

[0007] Hypochlorous acid is an efficient, biocompatible, non-toxic, non-irritant and broadspectrum antimicrobial agent. It is widely recognised in the art as an effective antimicrobial agent with activity against bacteria, viruses, fungi and spores. Due to its ability to affect multiple cellular target sites in a non-specific way, hypochlorous acid may be an attractive antimicrobial agent for use in cleansing wounds to reduce the risk of emerging resistance. However, hypochlorous acid can be challenging to use in commercial formulations due to its inherentinstability during storage. Additionally, the presence of biofilms e.g. in a wound to be cleansed, may reduce the antimicrobial efficacy of the hypochlorous acid.

[0008] Accordingly, there is also a need for wound cleansing solutions comprising hypochlorous acid that are formulated to increase the stability, shelf-life and / or antimicrobial activity of the hypochlorous acid. In particular, there is a need to enhance the efficacy of hypochlorous acid against biofilms and the microbes comprised in the protective environment thereof. There is also a need for wound cleansing solutions that exhibit a balance of efficacy and biocompatibility. The present disclosure seeks to address these needs with the various aspects and embodiments defined herein.SUMMARY

[0009] In a first aspect, provided is a wound cleansing composition comprising:(i) a surfactant in an amount of from about 0.1 to about 20% by weight of the composition;(ii) a chelating agent in an amount of from about 0.5 to about 10% by weight of the composition; and(iii) an aqueous solvent in an amount of at least about 50% by weight of the composition; wherein the composition does not include sodium oleate or a cationic surfactant; wherein the surfactant is selected from the group consisting of anionic surfactants, amphoteric surfactants, and mixtures thereof; and wherein the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof.

[0010] In a second aspect, the invention provides a method for cleansing and / or irrigating a wound, wherein said method comprises contacting said wound with a wound cleansing composition, wherein the wound cleansing composition comprises:(i) a surfactant in an amount of from about 0.1 to about 20% by weight of the composition;(ii) a chelating agent in an amount of from about 0.1 to about 10% by weight of the composition; and(iii) an aqueous solvent in an amount of at least about 50% by weight of the composition;wherein the surfactant is selected from the group consisting of anionic surfactants, amphoteric surfactants, and mixtures thereof; and wherein the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof.

[0011] In a third aspect, the invention provides a wound cleansing composition for use in cleansing and / or irrigating a wound, wherein the wound cleansing composition comprises:(i) a surfactant in an amount of from about 0.1 to about 20% by weight of the composition;(ii) a chelating agent in an amount of from about 0.1 to about 10% by weight of the composition; and(iii) an aqueous solvent in an amount of at least about 50% by weight of the composition; wherein the surfactant is selected from the group consisting of anionic surfactants, amphoteric surfactants, and mixtures thereof; and wherein the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof.

[0012] A fourth aspect provides a wound cleansing composition for use in treating a wound by disrupting one or more biofilms of the wound, wherein the composition is aqueous and comprises:(i) a surfactant in an amount of about 0.01 to about 10% by weight of the composition;(ii) a chelating agent in an amount of about 0.01 to about 10% by weight of the composition; and(iii) hypochlorous acid; wherein the surfactant is selected from anionic surfactants, non-ionic surfactants, amphoteric surfactants, and mixtures thereof; wherein the chelating agent is selected from citrates, oxalates, phosphates, ethylenediaminetetraacetates, and mixtures thereof; and wherein the composition has a pH from about 4 to about 8, and does not include a cationic surfactant.

[0013] An embodiment of the above aspect provides a wound cleansing composition for use in treating a wound by disrupting one or more biofilms of the wound, wherein the composition is aqueous and consists of:(i) a surfactant in an amount of about 0.01 to about 10% by weight of the composition;(ii) a chelating agent in an amount of about 0.01 to about 10% by weight of the composition; and(iii) hypochlorous acid; wherein the surfactant is selected from anionic surfactants, non-ionic surfactants, amphoteric surfactants, and mixtures thereof; wherein the chelating agent is selected from citrates, oxalates, phosphates, ethylenediaminetetraacetates, and mixtures thereof; and wherein the composition has a pH from about 4 to about 8 and does not include a cationic surfactant.

[0014] A further, fifth aspect provides a method for treating a wound by contacting the wound with an aqueous wound cleansing composition and disrupting one or more biofilms of the wound, wherein the composition is defined hereinabove.

[0015] A further, sixth aspect provides an aqueous wound cleansing composition comprising:(i) a surfactant in an amount of about 0.01 to about 5% by weight of the composition;(ii) a chelating agent in an amount of about 0.01 to about to about 5% by weight of the composition; and(iii) hypochlorous acid; wherein the surfactant is selected from sarcosinates, glutamates, isethionates, amphoacetates, amphodiacetates, betaines, amidoalkylbetaines, polysorbates, sulfates and mixtures thereof; wherein the chelating agent is selected from citrates, oxalates, phosphates, ethylenediaminetetraacetates, and mixtures thereof; provided that when the surfactant includes a betaine or an amidoalkylbetaine surfactant, the chelating agent is not an ethylenediaminetetracetate; wherein the composition has a pH of from about 4 to about 8, and does not include a cationic surfactant.

[0016] An embodiment of the above aspect provides an aqueous wound cleansing composition consisting of:(i) a surfactant in an amount of about 0.01 to about 5% by weight of the composition;(ii) a chelating agent in an amount of about 0.01 to about to about 5% by weight of the composition; and(iii) hypochlorous acid; wherein the surfactant is selected from sarcosinates, glutamates, isethionates, amphoacetates, amphodiacetates, betaines, amidoalkylbetaines, polysorbates, sulfates and mixtures thereof; wherein the chelating agent is selected from citrates, oxalates, phosphates, ethylenediaminetetraacetates, and mixtures thereof; provided that when the surfactant includes a betaine or an amidoalkylbetaine surfactant, the chelating agent is not an ethylenediaminetetracetate; wherein the composition has a pH of from about 4 to about 8 and does not include a cationic surfactant.

[0017] Also described herein are processes of preparing the above-defined compositions. These aspects and embodiments are set out in the appended independent and dependent claims. It will be appreciated that features of the dependent claims may be combined with each other and with features of the independent claims in combinations other than those explicitly set out in the claims. Furthermore, the approaches described herein are not restricted to specific embodiments such as those set out below, but include and contemplate any combinations of features presented herein. For example, the aqueous wound cleansing composition used for treating a wound by disrupting one or more biofilms of the wound may be defined by the preceding paragraph.

[0018] The foregoing and other objects, features, and advantages of the present disclosure will appear more fully hereinafter from a consideration of the detailed description that follows along with the accompanying drawings. It is to be expressly understood, however, that the drawings are for illustrative purposes and are not to be construed as defining the limits of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGSFig. 1 : Solution properties of sodium cocoyl glutamate (1 / 2 / 5 / 10% w / w) in combination with chelators: trisodium citrate, sodium phosphate dibasic, sodium oxalate and tetrasodium EDTA (1 / 2 / 5 / 10%).A) pH,B) surface tension, andC) osmolality of resulting combination solutions.Fig. 2: Solution properties of sodium cocoamphoacetate (1 / 2 / 5 / 10% w / w) in combination with chelators: trisodium citrate, sodium phosphate dibasic, sodium oxalate and tetrasodium EDTA (1 / 2 / 5 / 10%).A) pH,B) surface tension, andC) osmolality of resulting combination solutions.Fig. 3: Solution properties of sodium lauroyl sarcosinate (1 / 2 / 5 / 10% w / w) in combination with chelators: trisodium citrate, sodium phosphate dibasic, sodium oxalate and tetrasodium EDTA (1 / 2 / 5 / 10%).A) pH,B) surface tension, andC) osmolality of resulting combination solutions.Fig. 4: Z values of 33 combination candidate solutions in round 2 combination testing. Values were calculated relative to Prontosan as positive control. Prontosan is a wound irrigation solution for cleansing, rinsing and moisturising acute and chronic skin wounds. Additional comparative compositions Actolind, Octenilin and saline were also included in order to gauge efficacy. Actolind is a wound cleansing solution; octenilin is a wound irrigation solution.Fig. 5: Pareto plots showing significance of the effects of each factor (surfactant concentration / chelator concentration / pH) .A) sodium lauroyl sarcosinate + tetrasodium EDTA,B) sodium cocoamphoacetate + tetrasodium EDTA,C) sodium cocoyl glutamate + tetrasodium EDTA, andD) sodium cocoyl glutamate + trisodium citrate.The largest effect on response (Z value) is indicated by the bars that extend farthest. In all combinations, pH and chelator concentration display a larger impact on cleanser efficacy than surfactant concentration. The red horizontal line indicates which effects are statistically significant.Fig. 6: Cube plots showing relationship between 3 designated factors ([surfactant], [chelator] and pH), and response (Z value).A) sodium lauroyl sarcosinate + tetrasodium EDTA,B) sodium cocoamphoacetate + tetrasodium EDTA,C) sodium cocoyl glutamate + tetrasodium EDTA, andD) sodium cocoyl glutamate + trisodium citrate.Fig 7: Optical density measurements (595 nm) for S. aureus (top) and P. aeruginosa(bottom). Antibiofilm activity was monitored at 1, 0.5, 0.25, 0.125. 0.0625 and 0.03125 times the concentration of the neat solution following serial dilution across the test plate.A) 2 wt% Na cocoyl glutamate + 2 wt% tetrasodium EDTA.B) 2 wt% Na lauroyl sarcosinate + 2 wt% tetrasodium EDTA.C) 2 wt% Na cocamphoacetate + 2 wt% tetrasodium EDTA.D) 2 wt% Na cocoyl glutamate + 2 wt% trisodium citrate.Fig. 8: Total Viable Counts in CFU / peg for S. aureus (top) and P. aeruginosa (bottom). Antibiofilm activity was monitored at 1, 0.5, 0.25, 0.125. 0.0625 and 0.03125 times the concentration of the neat solution following serial dilution across the test plate.A) 2 wt% Na cocoyl glutamate + 2 wt% tetrasodium EDTA.B) 2 wt% Na lauroyl sarcosinate + 2 wt% tetrasodium EDTA.C) 2 wt% Na cocamphoacetate + 2 wt% tetrasodium EDTA.D) 2 wt% Na cocoyl glutamate + 2 wt% trisodium citrate.Fig. 9: Overview of the in vitro assay used to assess cleanser combination efficacy. Simulated biofilm / non-viable matter discs were added to each pre-warmed test solution. Solutions were incubated for 10 minutes at 37°C before being homogenised on a roller mixer for 3 minutes. The quantity of crystal violet that leached into the solutions increased with substrate degradation. To remove any precipitate or substrate residue, 1ml samples of each solution were centrifuged at 10,000 RPM for 5 minutes. 200pl of supernatant from each solution were added to a 96-well plate. Absorbance values were measured on a microplate reader at 595nm and used to derived Z-values relative to the positive control (Prontosan irrigation solution).Fig. 10: The debridement-enhancing effect of combining sodium lauroyl sarcosinate and EDTA on simulated wound slough / biofilm.Left: Both sodium lauroyl sarcosinate and EDTA individually failed to degrade the substrate at all concentrations tested (0.03-2.00% w / w). However, combinations of concentrations of each component (0.50-2.00 % w / w) induced visible degradation. Right: A, B, and C show substrate discs after incubation in 2.00% w / w sodium lauroyl sarcosinate, 2.00% EDTA, and 2.00% EDTA and 2.00% sodium lauroyl sarcosinate, respectively.Concentrations of the surfactant alone caused the formation of a white precipitate on the substrate surface but did not penetrate and alter its consistency. Concentrations of EDTA alone visibly degraded the substrate and released crystal violet into the solution, but centrifugation returned a colourless supernatant with crystal violet suspended in the pellet. Concentrations of each component in combination caused marked degradation of the substrate and the visible release and solubilisation of crystal violet that was not separated upon centrifugation.Fig. 11: The interrelationship between sodium lauroyl sarcosinate concentration, EDTA concentration, and debridement Z-value. For concentrations >0.50% w / w, the sum of the Z-values of the individual excipients was significantly lower than the Z-value of their corresponding combination. For combinations >0.25% w / w of both sodium lauroyl sarcosinate and EDTA, debridement Z-value appeared to increase exponentially with concentration.Fig 12: Speciation curve for chlorine, hypochlorous acid and hypochlorite in water.Fig 13: UV-Vis absorbance spectrum of DPD in the presence of free chlorine according to the Palin Test as described in Examples, Experimental 3, 1.1.1.Fig 14: Change in absorbance of Salvesan® solution diluted 1: 100 in the presence of DPD according to the Palin Test as described in Examples, Experimental 3, 1.1.1.Fig 15: Free chlorine absorbance of Salvesan® solution in the presence of DPD (according to the Palin Test as described in Examples, Experimental 3, 1.1.1) as a function of concentration of hypochlorous acid (ppm).Fig 16: pH stability study of (A) Simple science® and (B) Microdacyn® in the presence of a chelating agent selected from EDTA, phosphate and citrate as a function of time and temperature.Fig 17: pH change measured for the samples of Fig 16 after 3 weeks storage at 5°C, 20.7°C and 35°C.Fig 18: pH stability study of the effect of surfactants selected from benezethonium chloride (benz), Sodium dodecyl sulfate (SDS), cocamidopropyl betaine (coca), and Tween 20® with respect to time / temperature for Simple Science® solutions.Fig 19: pH stability study of the effect of surfactants selected from benezethonium chloride (benz), Sodium dodecyl sulfate (SDS), cocamidopropyl betaine (coca), and Tween 20® with respect to time / temperature for Microdacyn® solutions.Fig 20: pH change measured for the samples of (A) Figure 18 and (B) Figure 19 after 3 weeks storage at 5°C, 20.7°C and 35°C.Fig 21 : pH change measured for a control Salvesan® solution and Salvesan® solutions containing combinations of chelating agent and surfactant as described in Examples, Experimental 3, Section 3 after 3 weeks storage at 5°C, 20.7°C and 35°C.DETAILED DESCRIPTION

[0019] While various exemplary embodiments are described or suggested herein, other exemplary embodiments utilizing a variety of methods and materials similar or equivalent to those described or suggested herein are encompassed by the general inventive concepts. Those aspects and features of embodiments which are implemented conventionally may not be discussed or described in detail in the interests of brevity. It will thus be appreciated that aspects and features of apparatus and methods described herein which are not described in detail may be implemented in accordance with any conventional techniques for implementing such aspects and features.

[0020] As used in this specification and the claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Unless otherwise stated, the term "about" modifying the quantity of a component refers to variation in the numerical quantity that can occur, for example, through typical measuring and handling procedures used for making concentrates, mixtures or solutions in the real world; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of the materials employed, or to carry out the methods; and the like. The term “about” also encompassesamounts that differ due to different equilibrium conditions for a composition resulting from a particular initial mixture. Whether or not modified by the term "about", the claims include equivalents to the quantities. As used herein, the term “at least” includes the end value of the range that is specified. For example, “at least 10 wt%” includes the value 10 wt%.

[0021] The ranges provided herein provide exemplary amounts of each of the components. Each of these ranges may be taken alone or combined with one or more other component ranges.

[0022] As used herein, wt% means “weight percentage” as the basis for calculating a percentage. Unless indicated otherwise, all % values are calculated on a weight basis, and are provided with reference to the total weight of the product in which the substance is present. As used herein, w / w means “weight by weight” as the basis for calculating a percentage. Unless otherwise indicated, reference to "% by weight" (or “% by weight”) of a product or composition reflects the total wet weight of the product or composition (i.e., including water).

[0023] As used herein, “substantially free” means no more than trace amounts, i.e. the amount of the substance(s) concerned is negligible. In various embodiments, “substantially free” means no more than 1000 ppm, preferably no more than 100 ppm, more preferably no more than 10 ppm, even more preferably no more than 1 ppm of the substance(s) concerned.

[0024] In all aspects of the present disclosure, the disclosure includes, where appropriate, all enantiomers and tautomers of the compounds disclosed herein. A person skilled in the art will recognise compounds that possess optical properties (one or more chiral carbon atoms) or tautomeric characteristics. The corresponding enantiomers and / or tautomers may be isolated / prepared by methods known in the art.

[0025] Some of the compounds disclosed herein may exist as stereoisomers and / or geometric isomers - e.g. they may possess one or more asymmetric and / or geometric centres and so may exist in two or more stereoisomeric and / or geometric forms. The present disclosure contemplates the use of all the individual stereoisomers and geometric isomers of those compounds, and mixtures thereof. The terms used in the claims encompass these forms.Wound Cleansing Composition

[0026] As described herein, there is provided a wound cleansing composition comprising a surfactant, a chelating agent and an aqueous solvent where the composition does not includesodium oleate or a cationic surfactant, and the surfactant and chelating agent are as defined below.

[0027] There is also provided an aqueous wound cleansing composition comprising a surfactant, a chelating agent and hypochlorous acid, wherein the composition has a pH of from about 4 to about 8, and does not include a cationic surfactant, and wherein the surfactant and chelating agent are as defined below. In various embodiments, the aqueous wound cleansing composition consists essentially of, or consists of, a surfactant, a chelating agent and hypochlorous acid, wherein the composition has a pH of from about 4 to about 8, and does not include a cationic surfactant, and wherein the surfactant and chelating agent are as defined below. In various embodiments, such compositions are provided for use in treating a wound by disrupting one or more biofilms of the wound.

[0028] There are various stages of wound hygiene, with typical protocols comprising: (i) cleansing of the skin and wound, (ii) debridement of the wound, (iii) refashioning of the epithelial edge, and / or (iv) biofilm treatment and prevention. Thus, wound cleansing is typically the first stage before debridement and dressing for both acute and chronic wounds. Cleansing a wound means to clean the skin and the wound bed. It is a distinct stage in the routine treatment of wounds as defined in the guidelines proposed by the European Wound Management Association or EWMA. The EWMA explain how “debridement” refers to deeply removing adherent, dead or contaminated tissue from a wound, whereas “cleansing” is the removal of dirt (loose metabolic waste or foreign material). Typically, in wound cleansing the periwound skin and wound are decontaminated using wound cleansers to remove dead skin, loose debris, exudate and microbes to prevent re-colonisation of the wound. The stages differ by at least the point in time and the length of time of application of any composition or tool. Debridement, for example, is related to a longer time of application, during which it is possible for the tool / composition to be active on deeper layers of slough or non-viable tissue. Cleansing on the other hand, requires a fast-acting composition / tool. A wound cleansing composition may only be applied to the wound for about 10 minutes or less. Cleansing is vital to ensure that infection does not develop in the wound itself and that the integrity of the periwound skin is maintained.

[0029] Although wound cleansing and debridement are typically distinct stages in wound hygiene protocols, wound cleansers that also enhance the subsequent debridement stage and / or promote autolytic debridement would be particularly advantageous. Autolytic debridement refers to the lysis or breakdown of necrotic debris and devitalised tissues from a wound through the body’s own mechanisms, such as moist environments and endogenousenzymes. To this end, it has been unexpectedly found that the wound cleansing compositions described herein are effective in cleansing wounds while also enhancing the subsequent debridement step of wound treatment and / or promoting autolytic debridement as defined herein above.

[0030] For several aspects, it has been found surprisingly that the compositions disrupt biofilms comprised in the wound even in the absence of antimicrobial agents.

[0031] For other aspects, and without wishing to be bound by theory, it is believed that the combination of chelating agent and surfactant according to the present disclosure physically weakens and disrupts the components of the biofilm, such as the EPS, rendering the microbes contained in the biofilm more vulnerable to the hypochlorous acid and thus improving the antimicrobial efficacy of the hypochlorous acid while also contributing to the cleansing of the wound. For example, the wound cleansing compositions described herein have been found to be unexpectedly effective for the treatment of wounds having one or more biofilms.

[0032] Moreover, the compositions described herein may also slow and / or prevent the regrowth of biofilm after use.

[0033] The compositions described herein have also been found to exhibit the herein- described efficacies despite the relatively short contact times involved in wound cleansing, such as between wound dressings. The physical disruption of the biofilm and / or other wound components may enhance subsequent debridement steps, e.g. by mechanical means, through various mechanisms such as softening and / or disruption of the structures of said biofilms / components. The provision of a moist, clean environment through cleansing of the wound with the compositions described herein may also promote subsequent autolytic debridement. Thus, while the term “wound cleansing composition” as used herein refers in various embodiments to a composition for use in the wound cleansing step of a hygiene protocol as exemplified above, it is to be understood that said wound cleansing may also comprise the promotion of autolytic and / or subsequent debridement steps. The application of said compositions may also involve a degree of initial debridement, for example through a combination of the chemical effect of said composition on undesirable wound components such as biofilms and the physical effect of the mode of application, for example flow of the composition over the wound effected by irrigation.

[0034] It has also been found surprisingly that the hypochlorous acid comprised in the wound cleansing compositions described herein has good stability and thus the composition also has a long shelf-life. The terms “stability” and “shelf4ife” are defined herein below.

[0035] The wound cleansing composition disclosed herein is therefore advantageous in the treatment of chronic wounds and may also be used for irrigation between dressing applications.

[0036] In various embodiments the wound cleansing compositions described herein are nonantimicrobial. This means that they do not include any antimicrobial agents such as hypochlorous acid, silver compounds, polyhexamethylene biguanide, chlorhexidine, chlorhexidine salts, or the like.

[0037] Whilst the use of antiseptic wound cleansers is popular (owing to their ability to affect multiple cellular target sites in a non-specific way, thus reducing the likelihood of selecting for resistant strains of microorganisms), some resistance has been observed, and crossresistance between antibiotics and antiseptics has been detected. With the prospect of a postantibiotic era looming, ways to maintain our antimicrobial armamentarium should be considered in all aspects of healthcare, including wound cleansing. Normal saline is frequently employed for the cleansing of both acute and chronic wounds, although is often accompanied by a need for increased mechanical action during debridement, thereby resulting in increased patient discomfort. In contrast, the non-antimicrobial wound cleansers disclosed herein can effectively aid subsequent wound debridement and the removal of biofilm even in the absence of antimicrobial agents.

[0038] In other embodiments, the wound cleansing compositions described herein are antimicrobial due to the presence of hypochlorous acid.

[0039] The wound cleansing compositions described herein can be used on all wound types and across all settings, including difficult to access areas such as fissures or pockets. The wound cleansing compositions described herein can be used to loosen and aid removal of non-viable tissue, slough, biofilm and / or other pathogens as well as skin scales from the wound bed, wound edge, and peri-wound skin as part of a wound hygiene protocol. In addition to the properties discussed above, the compositions are also associated with one or more of the following advantageous properties: ease of use, suitability for repeated long-term use, good tolerance, safety, sting / pain-free use, non-irritant, non-toxic to tissue, fast-action, superiority to standard of care (e.g. water, saline), and not interfering with wound healing (e.g. granulation, epithelialisation).

[0040] For ease of reference, these and further features of the present disclosure are now discussed under appropriate section headings. However, the teachings under each section are not limited to the section in which they are found. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs.Hypochlorous acid

[0041] In various aspects, the composition of the present disclosure comprises hypochlorous acid. Hypochlorous acid is a weak acid and a natural oxidising agent that is used as a potent antimicrobial agent and which is produced naturally by human immune cells during infection. It is involved in the last step of the “oxidative burst” pathway in fighting infection and foreign substance invasion. When a cell detects invasion of foreign substance, it undergoes phagocytosis, in which the neutrophil ingests and internalize microorganisms or foreign particles. This phagocytosis event results in the secretion of reactive oxygen species and hydrolytic enzymes. The consumption of oxygen during the generation of reactive oxygen species (the “oxidative burst”) involves the activation of the enzyme NADPH oxidase, which produces large quantities of superoxide. This highly reactive oxygen species decays and is broken down to hydrogen peroxide. Hydrogen peroxide then combines with chloride ions by the action of the enzyme myeloperoxidase (MPO) to form hypochlorous acid (HOCI). HOCI exerts bactericidal properties and immediately destroys bacteria engulfed by the neutrophil.

[0042] HOCI is an efficient biocompatible non-toxic, non-irritant and broad-spectrum antimicrobial agent. However, hypochlorous acid can be challenging to use in commercial formulations due to its inherent instability during storage.

[0043] Hypochlorous acid only exists in solution - it is formed by dissolution of chlorine in water, and in aqueous solution hypochlorous acid partially dissociates into the anion hypochlorite OCk as shown in Scheme 1 .Cl2+ H2O H++ ci- + oci-Scheme 1

[0044] Commercial hypochlorous acid solutions are typically produced by the electrolysis of aqueous sodium chloride solutions. Such processes have been commonly known in the art formany decades, but are mainly used to produce hypochlorite (OCI-) and / or chlorine (Ch)- This is at least partly due to the poor stability of hypochlorous acid with respect to hypochlorite and chlorine. Methods focused on the preparation of hypochlorous acid are known in the art.

[0045] The method by which the hypochlorous acid of the present disclosure is obtained is not limited and the skilled person will be able to select appropriate methods and / or sources from those known in the art. As a consequence of the preparation process and the equilibrium state of the hypochlorous acid, in various embodiments the composition of the present disclosure will comprise amounts of the chlorine species other than hypochlorous acid as discussed above. Additionally, the composition may comprise sodium and chloride ions arising from the manufacturing process of the hypochlorous acid (e.g. electrolysis of aqueous sodium chloride) and / or from sodium chloride added thereafter (e.g. to adjust the osmolality of the solution).

[0046] It has been found that when used in the compositions of the present disclosure, hypochlorous acid has good stability and thus the composition may also have a long shelf-life. Increased stability is advantageous because HOCI is understood to have a higher antimicrobial efficacy than OCI- or Ch. As used herein, “stability” and “shelf-life” may be used interchangeably, and should be understood to refer to minimising the change in pH over time of the composition of the present disclosure; particularly during storage.

[0047] For example, in various embodiments, “stable” means that the pH of the composition may not change by more than ±2 pH, preferably ±1 pH, when the composition is stored for a given period of time. The composition may be stable for at least 3 months, preferably at least 6 months, more preferably at least 12 months. A person skilled in the art of the present disclosure will be able to select suitable storage conditions. For instance, the composition may be stored at ambient temperature (e.g. around 20°C), or preferably at around 5°C. Thus, in various embodiments, the compositions described herein are stored at temperatures less than about 20°C, preferably less than about 10°C, more preferably less than about 5°C. The composition is preferably stored in a dark, sealed container, the nature and material of which are not critical. For example, a dark polyethylene terephthalate (PET) or other moisture resistant plastic container may be used.

[0048] In various embodiments, the composition comprises up to about 50 ppm, up to about 100 ppm, up to about 150 ppm, or up to about 200 ppm hypochlorous acid, where “ppm” means “parts per million”. In various embodiments, the composition comprises at least about 10 ppm hypochlorous acid. Thus, in various embodiments the composition comprises from about 10ppm to about 50 ppm, from about 10 ppm to about 100 ppm, from about 10 ppm to about 150 ppm, or from about 10 ppm to about 200 ppm hypochlorous acid.

[0049] In addition to the enhanced stability discussed above, the combination of surfactant, chelating agent and hypochlorous acid according to the present disclosure has been found to lead to improved antimicrobial efficacy, in particular when treating wounds comprising one or more biofilms. It has been found unexpectedly that the surfactant and chelating agent enhance and cooperate with the hypochlorous acid to enhance antimicrobial activity, particularly against microbes comprised in biofilms.Chelating agent or Chelator

[0050] Chelating agents are organic or inorganic compounds capable of binding metal ions to form complex ring or cage-like structures called ‘chelates’. In the case of chronic wound care, chelation of metal ions removes their ability to interact with the surrounding biochemical matrix, thereby limiting their effects and rendering them effectively inert. Metal ions such as Mg2+and Ca2+have been shown to stabilise biofilms formed by a variety of microorganisms. Multi-valent metal ions enhance the structural integrity of bacterial biofilms via electrostatic interactions that serve to crosslink the polyanionic alginate and similar polysaccharide chains. Despite the association of high-density EPS formation with specific species of bacteria, the resultant polymeric architecture is not an exclusive resource belonging to the producing organism. Instead, it can act as a shared housing utilised by additional species of bacteria less adept at EPS production. Therefore, removal of the ions holding the matrix together is not a speciesspecific strategy, rather a more generalised anti-biofilm measure aimed at disrupting the entire wound-associated bacterial ecosystem.

[0051] Multi-valent metal ions are also implicated in stabilising extracellular DNA (eDNA), an integral matrix component of multiple, clinically relevant biofilms, including those formed by Pseudomonas aeruginosa and Staphylococcus aureus. Specifically, negatively charged eDNA binds to divalent metal ions which promotes bacterial aggregation via cationic bridging. As such, chelation of metal ions can result in EPS disruption, prevention of EPS formation, dispersal of planktonic cells (free-living, single cells) from the biofilm and, in high concentration, cellular lysis. Therefore, removal of such cations from the biofilm matrix may enhance wound cleansing via alteration of both the cellular phenotype and genotype.

[0052] In the first, second and third aspects of the present disclosure, the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, anethylenediaminetetraacetate salt, and mixtures thereof. In various embodiments the salts are metal ion or ammonium salts. The metal ion of said salts is not limited. In various embodiments, metal ion salts are preferred and may be selected from sodium and / or potassium salts. In particularly preferred embodiments, the salts are sodium salts.

[0053] In the fourth aspect of the present disclosure, the chelating agent is selected from the group consisting of citrates, phosphates, oxalates, ethylenediaminetetraacetates, and mixtures thereof. In various embodiments, the citrates, phosphates, oxalates, ethylenediaminetetraacetates, and mixtures thereof are citrate salts, phosphate salts, oxalate salts, ethylenediaminetetraacetate salts, and mixtures thereof. In various embodiments the salts are metal ion or ammonium salts. The metal ion of said salts is not limited. In various embodiments, metal ion salts are preferred and may be selected from sodium and / or potassium salts. In particularly preferred embodiments, the salts are sodium salts.

[0054] The ethylenediaminetetraacetate salt may be a mixture of di-, tri-, or tetra-basic salts of ethylenediaminetetraacetate (EDTA). The EDTA salt may, for instance, be a di-sodium salt of EDTA, or calcium di-sodium salt of EDTA, or tetra-sodium salt of EDTA. In various embodiments, the salt of EDTA is a mixture of salts of EDTA. It is believed that EDTA, when present, will have a form which is dependent on the pH of the wound site. In various embodiments, EDTA may be added to the composition as a tetra-basic salt of EDTA such as tetrasodium EDTA.

[0055] The citrate salt may similarly be a mono-, di- or tri-citrate salt. In various embodiments the citrate salt may be mono-, di- or tri-potassium citrate or mono-, di- or tri-sodium citrate. In preferred embodiments, the citrate salt is a tri-citrate salt such as trisodium citrate.

[0056] The phosphate salt may be an ortho-phosphate, a pyrophosphate, a tripolyphosphate or a derivatised phosphate. The phosphate is typically in the form of a potassium or sodium salt. Examples include potassium phosphate dibasic, potassium pyrophosphate, tri-sodium ascorbate phosphate, disodium phosphate and sodium tripolyphosphate. In preferred embodiments the phosphate salt is a di-phosphate salt such as disodium phosphate.

[0057] In various embodiments the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. The citrate salt, phosphate salt and EDTA salt being defined as above. In various embodiments, the salts are metal ion or ammonium salts. The metal ion of said salts are not limited. In various embodiments, metal ion salts are preferred and may be selected from sodium and / orpotassium salts. In particularly preferred embodiments, the salts are sodium salts. Thus, in various preferred embodiments, the chelating agent is selected from the group consisting of sodium salts of citrate, phosphate, EDTA and mixtures thereof.

[0058] In various embodiments the chelating agent is selected from the group consisting of a citrate salt, an EDTA salt and mixtures thereof. Preferred are EDTA salts such as tetrasodium EDTA.

[0059] In the fifth aspect of the present disclosure, and in various embodiments of the other aspects disclosed herein, the chelating agent is selected from citrates, oxalates, phosphates, ethylenediaminetetraacetates, and mixtures thereof; the citrates, oxalates, phosphates, ethylenediaminetetraacetates, and mixtures thereof being defined as for the first aspect above; provided that when the surfactant includes a betaine or an amidoalkylbetaine surfactant, the chelating agent is not an ethylenediaminetetracetate.Surfactant

[0060] In the present disclosure, the wound cleansing composition includes a surfactant. The composition of the first to third aspects does not, however, include sodium oleate. Sodium oleate is the sodium salt of oleic acid, a monounsaturated fatty acid. It is an anionic surfactant and component of commercial saps. It is not included in the wound cleansing composition of the present invention, unlike the debridement compositions exemplified in WO 2021 / 186188.

[0061] Surfactants are widely used as detergents, emulsifiers, wetting agents, foaming agents and dispersants in the cosmetics, hygiene, food and oil industries. They are also used in a clinical setting including advanced wound care. As surface-active agents, surfactants are amphiphilic; they contain both hydrophilic and hydrophobic components and are therefore capable of lowering the surface tension at the solid / liquid interface, allowing for greater penetration of fluids into the wound bed and subsequent removal of biological materials by irrigating agents such as water or saline.

[0062] Surfactants can be categorised as non-ionic surfactants, cationic surfactants, anionic surfactants, or amphoteric surfactants. Non-ionic surfactants include poloxamers and polysorbates. Poloxamers are non-ionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene flanked by two hydrophilic chains of polyoxyethylene. Trade names such as Pluronic, Kolliphor (pharma grade) and Synperonic are known in the art. Non-ionic surfactants are reported to be effective in the solubilisation and disaggregation of proteins. They are seemingly able to block the adhesion of certain proteins thus reducingmicrobial adhesion. Indeed, wound irrigation solutions containing non-ionic surfactants have been demonstrated to effectively cleanse and remove debris from wounds.

[0063] The present inventors found, however, for the first to third aspects of the present disclosure that a surfactant selected from the group consisting of anionic, amphoteric and mixtures thereof, is surprisingly able to effectively cleanse and remove debris from wounds when used in combination with the chelating agent defined above at the recited concentration ranges and in an aqueous solvent. Particular advantages were seen with an anionic surfactant.

[0064] T o the contrary, the compositions of the fourth to sixth aspects of the present disclosure do not include a cationic surfactant. Thus, in various embodiments of these aspects, the surfactant is selected from anionic surfactants, non-ionic surfactants, amphoteric surfactants, and mixtures thereof. The present inventors have found that a surfactant selected from the group consisting of anionic surfactants, non-ionic surfactants, amphoteric surfactants, and mixtures thereof, is surprisingly able to effectively cleanse and remove debris from wounds when used in combination with the chelating agent defined above in a wound cleansing composition as defined herein. In particular, said combinations have been found to be compatible with hypochlorous acid in said compositions, such that said compositions have enhanced stability and increased antimicrobial efficacy as described herein.

[0065] In various embodiments of the fourth to sixth aspects, the surfactant is a non-ionic surfactant, preferably a polysorbate. Polysorbate surfactants are well known in the art. They are oily liquids derived from ethoxylated sorbitan esterified with fatty acids, and commercial examples include surfactants under the “Tween®” brand name, such as Tween® 20 (polyoxyethylene (20) sorbitan monolaurate; 2-{2-[3,4-bis(2-hydroxyethoxy)oxolan-2-yl]-2-(2- hydroxyethoxy)ethoxy}ethyl dodecanoate). Other brand names include Scattics, Alkest and Canarcel. Further examples are polysorbate 40, polysorbate 60 and polysorbate 80, where the number relates to the type of major fatty acid associated with the polyoxyethylene molecule: monolaurate is indicated by 20, monopalmitate is indicated by 40, monostearate is indicated by 60, and monooleate is indicated by 80.

[0066] The anionic surfactant for all aspects may include all forms of lipophilic oligomeric hydrocarbon and / or polyethoxylate with a negatively charged hydrophilic head group such as carboxylate, sulphate, sulphonate, sulphonated ester, sulphated ester, sulphated amide, carboxylated amide, or phosphate anionic head group. For example, including a fatty acid or fatty acid salt, selected from a fatty acid glutamate salt, sarcosine salt, sarcosinate salt, isethionate salt and taurate salt. The anionic surfactant is not a sulphosuccinate salt.

[0067] In various embodiments, the anionic surfactant is selected from glutamates, sarcosinates, isethionates and sulfates.

[0068] In various embodiments, the anionic surfactant is selected from a glutamate salt, a sarcosinate salt, and an isethionate salt, preferably a fatty acid glutamate salt, sarcosinate salt, or isethionate salt. The fatty acid may comprise 8 to 24 carbon atoms, such as 10 to 20 carbon atoms, preferably 12 to 18 carbon atoms. The salt of the fatty acid glutamate, sarcosinate or isethionate may be an alkali metal or alkaline earth metal salt, typically an alkali metal salt. The alkali metal may, for instance, be sodium or potassium, preferably the alkali metal is sodium.

[0069] The fatty acid of the fatty acid salt may be saturated or unsaturated. When unsaturated, the unsaturation may be mono- or di-unsaturation, i.e. the fatty acid may be a mono- or diunsaturated fatty acid. In various embodiments, the fatty acid of the fatty acid salt is a monounsaturated fatty acid having 8 to 24 carbon atoms and is classified as a mono-unsaturated fatty acid. Examples of fatty acids include stearic, ricinoleic, oleic, eladic, palmitic, erucic, behenic, lauric, myristic, or lineolic acid. In various embodiments, the fatty acid is selected from the group consisting of palmitic acid, lauric acid, myristic acid, and mixtures thereof.

[0070] As noted herein, the wound cleansing composition of the first to third aspects in the present disclosure does not include sodium oleate.

[0071] In various embodiments the anionic surfactant is selected from a fatty acid glutamate salt, a fatty acid sarcosinate salt, and mixtures thereof, wherein the fatty acid comprises 8 to 24 carbon atoms. In preferred embodiments, the anionic surfactant is selected from a fatty acid glutamate salt, a fatty acid sarcosinate salt, and mixtures thereof, wherein the fatty acid comprises 10 to 20 carbon atoms. As noted above, the salt of the fatty acid glutamate or fatty acid sarcosinate may be an alkali metal or alkaline earth metal salt, typically an alkali metal salt. The alkali metal may, for instance, be sodium or potassium, preferably the alkali metal is sodium.

[0072] In various embodiments the anionic surfactant is selected from the group consisting of a lauroyl sarcosinate salt, a cocyl glutamate salt, and mixtures thereof. In various embodiments the salts are metal ion salts. The metal ion of said salts is not limited. In various embodiments, sodium salts are preferred. Thus, in various embodiments, the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, and mixtures thereof.

[0073] In various embodiments, the metal ions of the salt of the chelating agent and the salt of the anionic surfactant are the same. Preferably, both the chelating agent and surfactant are sodium salts.

[0074] Amphoteric surfactants may also be called zwitterionic surfactants, because they are neutral compounds comprising formal unit electrical charges of opposite sign. Amphoteric surfactants include amphoacetates, amphodiacetates, betaines, and amidoalkylbetaines. In the fourth to sixth aspects, when the surfactant includes a betaine or an amidoalkylbetaine surfactant, the chelating agent is not an ethylenediaminetetraacetate. In various embodiments the amphoteric surfactant is selected from a hydrocarbyl-amphoacetate, a hydrocarbyl, amphodiacetate, a hydrocarbyl betaine, a hydrocarbyl-amidoalkylbetaine and mixtures thereof, wherein the hydrocarbyl groups contain 6 to 24, or 8 to 24, or 10 to 20 carbon atoms.

[0075] The amphoteric surfactant of all aspects may include a hydrocarbyl-amphoacetate salt, a hydrocarbyl-amphodiacetate salt, and mixtures thereof, wherein the hydrocarbyl groups contain 6 to 24, or 8 to 24, or 10 to 20 carbon atoms. As used herein, the term “hydrocarbyl” includes a group such as alkyl, aryl, aralkyl, alkaryl, cycloalkyl or alkenyl, which may be linear or branched, and / or saturated or unsaturated. In one embodiment, the hydrocarbyl may be a linear or branched alkyl or alkenyl group. The hydrocarbyl may be a fatty acid as defined above, such as a fatty acid having 8 to 24 carbon atoms.

[0076] In various embodiments, the amphoteric surfactant is a hydrocarbyl-amphoacetate salt. In preferred embodiments, the amphoteric surfactant is a fatty acid amphoacetate salt, wherein the fatty acid comprises 8 to 24 carbon atoms. In a particularly preferred embodiment, the amphoteric surfactant is a cocoamphoacetate salt. In various embodiments the salts are metal ion salts. The metal ion of said salts is not limited. In various embodiments, sodium salts are preferred. Thus, in various embodiments, the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, and mixtures thereof.

[0077] Thus, in various embodiments, the surfactant is sodium cocoamphoacetate.

[0078] In various embodiments, the metal ions of the salt of the chelating agent and the salt of the amphoteric surfactant are the same. Preferably, both the chelating agent and surfactant are sodium salts.

[0079] In various embodiments, the surfactant is selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixturesthereof, wherein the fatty acid has 8 to 24 carbon atoms. In various embodiments the surfactant is selected from the group consisting of a lauroyl sarcosinate, a cocyl glutamate, a cocoamphoacetate, and mixtures thereof. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof.

[0080] In various embodiments the salts are metal ion salts. The metal ion of said salts is not limited. In various embodiments, sodium salts are preferred. Thus, in various embodiments, the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof.Combination of chelating agent and surfactant; Combination of chelating agent, surfactant and Hypochlorous acid

[0081] For the first to third aspects, it has been found that the chelating agents and the anionic and / or amphoteric surfactants described herein operate together to disrupt biofilms and cleanse wounds. For the fourth to sixth aspects, it has been found that the chelating agents and the surfactants described herein operate together to disrupt biofilms and cleanse wounds, and moreover cooperate to enhance the stability, shelf-life and / or antimicrobial efficacy of hypochlorous acid in the composition of the present disclosure.

[0082] Without wishing to be bound by theory, it is believed that each of the chelating agent and the surfactant exert their action via different physicochemical means. For example, the chelating agent is believed to coordinate metal ions such as those present in the matrix and biofilm, weakening the structure of the biofilm. On the other hand, the anionic and / or amphoteric surfactant is believed to aid wetting (and hence aiding penetration of fluids into the wound bed), to solubilise proteins, DNA, and other components present in the wound.

[0083] In various embodiments, the combination of chelating agent and surfactant, and optionally hypochlorous acid, have been found to be synergistic. Synergy in the context of the present disclosure can be measured in a number of ways that conform to the generally accepted opinion that “synergy is an effect greater than additive”. One of the ways to assess whether synergy has been observed is to use the “chequerboard” technique. This is a well- accepted method that leads to the generation of a value called the fractional inhibitory concentration index (FICI). Orhan et al J. Clin. Microbiol. 2005, 43(1):140 describes the chequerboard method and analysis in the paragraph bridging pages 140-141 , and explains that the FICI value is a ratio of the sum of the MIC (Minimum Inhibitory Concentration) level of each individual component alone and in the mixture. The combination is considered synergisticwhen the ZFIC is <0.5, indifferent when the ZFIC is >0.5 but <4.0, and antagonistic when the ZFIC is >4.0.

[0084] In the context of wounds hygiene as described herein, synergy may be exhibited in that the chelating agent and surfactant do not cleanse / irrigate the wound effectively and / or disrupt the biofilm when used without the other, but in combination said chelating agent and surfactant are effective at cleansing the wound and / or disrupting the biofilm. Similarly, biofilms that may be resistant to treatment with hypochlorous acid alone may be rendered susceptible to such treatment in the presence of the chelating agent and surfactant such that the wound is effectively cleansed and / or the microbes of the biofilm killed.

[0085] Itwould be understood by the person skilled in the art that the definition of the surfactant set out above is combinable with the definition of the chelating agent. For example, in various embodiments the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof, and the surfactant is an anionic surfactant selected from a glutamate salt, a sarcosinate salt, and an isethionate salt, preferably a fatty acid glutamate salt, sarcosinate salt, or isethionate salt, wherein the fatty acid comprises 8 to 24 carbon atoms.

[0086] Alternatively, the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof, and the surfactant is an amphoteric surfactant which is a hydrocarbyl-amphoacetate salt. In preferred embodiments, the amphoteric surfactant is a fatty acid amphoacetate salt, wherein the fatty acid comprises 8 to 24 carbon atoms.

[0087] In various embodiments, the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof, and the surfactant is a non-ionic surfactant, preferably a polysorbate.

[0088] In various embodiments, the chelating agent is a citrate salt, and the surfactant is a non-ionic surfactant, preferably a polysorbate. In various embodiments, the chelating agent is an oxalate salt, and the surfactant is a non-ionic surfactant, preferably a polysorbate.

[0089] In all of these embodiments, the salts are metal ion salts. The metal ion of said salts is not limited. In various embodiments, sodium salts are preferred.

[0090] In various embodiments the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, andmixtures thereof; and the surfactant is selected from the group consisting of a lauroyl sarcosinate, a cocyl glutamate, a cocoamphoacetate, and mixtures thereof. The salts are metal ion salts. The metal ion of said salts is not limited. In various embodiments, sodium salts are preferred. For example, in various embodiments the chelating agent is selected from the group consisting of trisodium citrate, disodium phosphate, disodium oxalate, tetrasodium ethylenediaminetetraacetate, and mixtures thereof; and the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof.

[0091] In various embodiments, the chelating agent is a citrate salt, and the surfactant is selected from the group consisting of a sarcosinate salt, a glutamate salt, an amphoacetate salt, and mixtures thereof. In preferred embodiments, the surfactant is selected from the group consisting of a fatty acid sarcosinate salt, a fatty acid glutamate salt, a fatty acid amphoacetate salt, and mixtures thereof, wherein the fatty acid has 10 to 20 carbon atoms. In particularly preferred embodiments, the chelating agent is a citrate salt and the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof.

[0092] In various embodiments, the chelating agent is a phosphate salt and the surfactant is selected from the group consisting of a sarcosinate salt, a glutamate salt, an amphoacetate salt, and mixtures thereof. In preferred embodiments, the surfactant is selected from the group consisting of a fatty acid sarcosinate salt, a fatty acid glutamate salt, a fatty acid amphoacetate salt, and mixtures thereof, wherein the fatty acid has 10 to 20 carbon atoms. In particularly preferred embodiments, the chelating agent is a phosphate salt and the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof.

[0093] In various embodiments, the chelating agent is an oxalate salt and the surfactant is selected from the group consisting of a sarcosinate salt, a glutamate salt, an amphoacetate salt, and mixtures thereof. In preferred embodiments, the surfactant is selected from the group consisting of a fatty acid sarcosinate salt, a fatty acid glutamate salt, a fatty acid amphoacetate salt, and mixtures thereof, wherein the fatty acid has 10 to 20 carbon atoms. In particularly preferred embodiments, the chelating agent is an oxalate salt and the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof.

[0094] In various embodiments, the chelating agent is an ethylenediaminetetraacetate salt and the surfactant is selected from the group consisting of a sarcosinate salt, a glutamate salt, an amphoacetate salt, and mixtures thereof. In preferred embodiments, the surfactant is selected from the group consisting of a fatty acid sarcosinate salt, a fatty acid glutamate salt, a fatty acid amphoacetate salt, and mixtures thereof, wherein the fatty acid has 10 to 20 carbon atoms. In particularly preferred embodiments, the chelating agent is a citrate salt and the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof. In other particularly preferred embodiments, the chelating agent is an ethylenediaminetetraacetate salt and the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof.

[0095] In various embodiments, the chelating agent is a lauroyl sarcosinate salt and the chelating agent is an ethylenediaminetetraacetate salt.

[0096] In various embodiments, the chelating agent is a phosphate salt and / or an ethylenediaminetetraacetate salt and the surfactant is selected from the group consisting of a sarcosinate salt, a glutamate salt, an amphoacetate salt, and mixtures thereof. In preferred embodiments, the surfactant is selected from the group consisting of a fatty acid sarcosinate salt, a fatty acid glutamate salt, a fatty acid amphoacetate salt, and mixtures thereof, wherein the fatty acid has 10 to 20 carbon atoms. In particularly preferred embodiments, the chelating agent is a phosphate salt and / or an ethylenediaminetetraacetate salt and the surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof.

[0097] In various embodiments, the surfactant is a polysorbate and the chelating agent is an ethylenediaminetetraacetate salt and / or a phosphate salt.

[0098] In various embodiments, the surfactant is a lauroyl sarcosinate salt and the chelating agent is an ethylenediaminetetraacetate salt and / or a phosphate salt.

[0099] In any of the above-described embodiments, the chelating agent and surfactant may each be sodium salts.Concentrations of surfactant and chelating agent

[0100] Each of the surfactant and chelating agent may be present in an amount suitable to provide the desired cleansing and / or irrigation effect on the wound and / or to enhance theefficacy of the hypochlorous acid. In the first to third aspects, the specific combination of surfactant and chelating agent and their concentrations have been found by the inventors to provide a composition with antibiofilm activity without the need for an antimicrobial agent. In the fourth to sixth aspects, the specific combination of surfactant and chelating agent and their concentrations have been found by the inventors to provide antibiofilm activity while stabilising and enhancing the efficacy of the hypochlorous acid. In particular, the surfactant and chelating agent are shown to disrupt non-viable proteins / carbohydrates and together with the hypochlorous acid demonstrate enhanced efficacy when compared to commercially available cleanser solutions and saline.First to Third Aspects

[0101] For the first to third aspects, the surfactant is present in an amount of about 0.1 to about 20% by weight of the composition. The surfactant being defined according to the embodiments above. In various embodiments, the surfactant is present in an amount of about 0.5 to about 10% by weight of the composition. In preferred embodiments, the surfactant is present in an amount of about 1% to about 5% by weight of the composition.

[0102] In various embodiments the surfactant is present in an amount of about 0.5 to about 10% by weight of the composition and selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof.

[0103] In various embodiments the surfactant is present in an amount of about 1% to about 5% by weight of the composition and selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof.

[0104] In various embodiments, the surfactant is an anionic surfactant and is present in the composition in an amount of from about 0.1 to about 10% by weight based on the total weight of the composition. In preferred embodiments, the anionic surfactant is present in the composition in an amount of from about 0.5 to about 10% by weight based on the total weightof the composition, such as from about 1 to about 5% by weight based on the total weight of the composition.

[0105] In each of these embodiments, the anionic surfactant may be selected from a fatty acid glutamate salt, a fatty acid sarcosinate salt, and mixtures thereof, wherein the fatty acid comprises 8 to 24 carbon atoms. In preferred embodiments, the anionic surfactant is selected from a fatty acid glutamate salt, a fatty acid sarcosinate salt, and mixtures thereof, wherein the fatty acid comprises 10 to 20 carbon atoms. Particularly preferred are lauroyl sarcosinate salts and cocyl glutamate salts and mixtures thereof.

[0106] In various embodiments, the surfactant is an amphoteric surfactant and is present in the composition in an amount of from about 0.1 to about 10% by weight based on the total weight of the composition. In preferred embodiments, the amphoteric surfactant is present in the composition in an amount of from about 0.5 to about 10% by weight based on the total weight of the composition, such as from about 1 to about 5% by weight based on the total weight of the composition.

[0107] In each of these embodiments, the amphoteric surfactant may be a hydrocarbyl- amphoacetate salt, a hydrocarbyl-amphodiacetate salt, and mixtures thereof, wherein the hydrocarbyl groups contain 6 to 24, or 8 to 24, or 10 to 20 carbon atoms. In preferred embodiments, the amphoteric surfactant is a fatty acid amphoacetate salt, wherein the fatty acid comprises 8 to 24 carbon atoms. In a particularly preferred embodiment, the amphoteric surfactant is a cocoamphoacetate salt.

[0108] The chelating agent is present in an amount of from about 0.1 to about 10% by weight of the composition. In various embodiments, including the wound cleansing composition defined in the appended claims, the chelating agent is present in an amount of about 0.5 to about 10% by weight of the composition. In preferred embodiments, the chelating agent is present in an amount of about 1 % to about 2% by weight of the composition.

[0109] In various embodiments the chelating agent is present in an amount of about 0.5 to about 10% by weight of the composition and selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. Preferred are EDTA salts such as tetrasodium EDTA.

[0110] In various embodiments the chelating agent is present in an amount of about 1 % to about 2% by weight of the composition and selected from the group consisting of a citrate salt,a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. Preferred are EDTA salts such as tetrasodium EDTA.

[0111] In various embodiments, the surfactant is present in the composition in an amount of from about 0.1 to about 10% by weight based on the total weight of the composition and the chelating agent is present in the composition in an amount of from about 0.1 to about 10% by weight, from about 0.5 to about 10% by weight, or from about 0.5 to about 5% by weight based on the total weight of the composition.

[0112] In such embodiments the surfactant may be selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof. The chelating agent may be selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. Preferred are EDTA salts such as tetrasodium EDTA.

[0113] In various embodiments, the surfactant is present in the composition in an amount of from about 0.5 to about 10% by weight based on the total weight of the composition and the chelating agent is present in the composition in an amount of from about 0.1 to about 10% by weight, from about 0.5 to about 10% by weight, or from about 0.5 to about 5% by weight based on the total weight of the composition.

[0114] In such embodiments the surfactant may be selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof. The chelating agent may be selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. Preferred are EDTA salts such as tetrasodium EDTA.

[0115] In various embodiments, the surfactant is present in the composition in an amount of from about 1 to about 5% by weight based on the total weight of the composition and the chelating agent is present in the composition in an amount of from about 0.5 to about 10% by weight, or from about 0.5 to about 5% by weight based on the total weight of the composition.

[0116] In such embodiments the surfactant may be selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof. The chelating agent may be selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. Preferred are EDTA salts such as tetrasodium EDTA.

[0117] The weight ratio of chelating agent to surfactant may be controlled in order to further enhance the advantageous properties of the wound cleansing composition. In various embodiments the weight ratio of chelating agent to surfactant is about 10:1 to about 1 :10. In preferred embodiments the weight ratio of chelating agent to surfactant is about 5:1 to about 1 :5. In particularly preferred embodiments the weight ratio is about 4:1 to about 1 :1.Fourth to Sixth Aspects

[0118] In the fourth to sixth aspects, the surfactant is present in an amount of about 0.01 to about 10% by weight of the composition. The surfactant being defined according to the embodiments above. In various embodiments, the surfactant is present in an amount of about 0.01 to about 5% by weight of the composition. In preferred embodiments, the surfactant is present in an amount of 0.01 to about 2% by weight. In particularly preferred embodiments, the surfactant is present in an amount of 0.01 to about 1% by weight.

[0119] In various embodiments the surfactant is present in an amount of about 0.01 to about 10% by weight of the composition and selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof.

[0120] In various embodiments the surfactant is present in an amount of about 0.01% to about 5% by weight of the composition and selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof.

[0121] In various embodiments the surfactant is present in an amount of about 0.01% to about 2% by weight of the composition and selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof. In preferred embodiments, the surfactant is selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof.

[0122] In various embodiments the surfactant is present in an amount of about 0.01 to about 10% by weight of the composition and selected from a hydrocarbyl-amphoacetate, a hydrocarbyl-amphodiacetate, a hydrocarbyl betaine, a hydrocarbyl-amidoalkylbetaine and mixtures thereof, wherein the hydrocarbyl groups comprise 8 to 24 carbon atoms. In preferred embodiments, the surfactant is selected from a fatty acid amphoacetate or fatty acid amidoalkylbetaine wherein the fatty acid comprises 8 to 24 carbon atoms.

[0123] In various embodiments the surfactant is present in an amount of about 0.01 to about 5% by weight of the composition and selected from a hydrocarbyl-amphoacetate, a hydrocarbyl-amphodiacetate, a hydrocarbyl betaine, a hydrocarbyl-amidoalkylbetaine and mixtures thereof, wherein the hydrocarbyl groups comprise 8 to 24 carbon atoms. In preferred embodiments, the surfactant is selected from a fatty acid amphoacetate or fatty acid amidoalkylbetaine wherein the fatty acid comprises 8 to 24 carbon atoms.

[0124] In various embodiments the surfactant is present in an amount of about 0.01 to about 2% by weight of the composition and selected from a hydrocarbyl-amphoacetate, a hydrocarbyl-amphodiacetate, a hydrocarbyl betaine, a hydrocarbyl-amidoalkylbetaine and mixtures thereof, wherein the hydrocarbyl groups comprise 8 to 24 carbon atoms. In preferred embodiments, the surfactant is selected from a fatty acid amphoacetate or fatty acid amidoalkylbetaine wherein the fatty acid comprises 8 to 24 carbon atoms.

[0125] In various embodiments the surfactant is present in an amount of about 0.01 to about 10% by weight of the composition and is a non-ionic surfactant such as a polysorbate. In preferred embodiments the surfactant is present in an amount of about 0.01 to about 5% by weight of the composition and is a non-ionic surfactant such as a polysorbate. In particularly preferred embodiments the surfactant is present in an amount of about 0.01 to about 2% by weight of the composition and is a non-ionic surfactant such as a polysorbate.

[0126] In various, alternative embodiments, the surfactant is an anionic surfactant and is present in the composition in an amount of from about 0.01 to about 10% by weight based onthe total weight of the composition. In preferred embodiments, the anionic surfactant is present in the composition in an amount of from about 0.01 to about 5% by weight based on the total weight of the composition, particularly preferred is an amount of from about 0.01 to about 2% by weight based on the total weight of the composition. In each of these embodiments the surfactant may be selected from glutamates, sarcosinates, isethionates and sulfates. In each of these embodiments, the anionic surfactant may be selected from a fatty acid glutamate salt, a fatty acid sarcosinate salt, and mixtures thereof, wherein the fatty acid comprises 8 to 24 carbon atoms. In preferred embodiments, the anionic surfactant is selected from a fatty acid glutamate salt, a fatty acid sarcosinate salt, and mixtures thereof, wherein the fatty acid comprises 10 to 20 carbon atoms. Particularly preferred are lauroyl sarcosinate salts and cocyl glutamate salts and mixtures thereof.

[0127] In various, alternative embodiments, the surfactant is an amphoteric surfactant and is present in the composition in an amount of from about 0.01 to about 10% by weight based on the total weight of the composition. In preferred embodiments, the amphoteric surfactant is present in the composition in an amount of from about 0.01 to about 5% by weight based on the total weight of the composition, particularly preferred is an amount of from about 0.1 to about 2% by weight based on the total weight of the composition. In each of these embodiments, the amphoteric surfactant may be a hydrocarbyl-amphoacetate salt, a hydrocarbyl-amphodiacetate salt, and mixtures thereof, wherein the hydrocarbyl groups contain 6 to 24, or 8 to 24, or 10 to 20 carbon atoms. In preferred embodiments, the amphoteric surfactant is a fatty acid amphoacetate salt, wherein the fatty acid comprises 8 to 24 carbon atoms. In a particularly preferred embodiment, the amphoteric surfactant is a cocoamphoacetate salt.

[0128] The chelating agent is present in an amount of from about 0.01 to about 10% by weight of the composition. In various, preferred embodiments, including the wound cleansing composition defined in the appended claims, the chelating agent is present in an amount of about 0.01 to about 5% by weight of the composition. In particularly preferred embodiments, the chelating agent is present in an amount of about 0.01% to about 1 % by weight of the composition.

[0129] In various, preferred embodiments the chelating agent is present in an amount of about 0.01 to about 5% by weight of the composition and selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. Particularly preferred are EDTA salts such as tetrasodium EDTA and phosphate salts such as disodium phosphate.

[0130] In various, particularly preferred embodiments the chelating agent is present in an amount of about 0.01 to about 1 % by weight of the composition and selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. Especially preferred are EDTA salts such as tetrasodium EDTA and phosphate salts such as disodium phosphate.

[0131] In the embodiments wherein the chelating agent is an ethylenediaminetetraacetate, said ethylenediaminetetraacetate may be present in an amount of no greater than about 1% by weight of the composition, preferably in an amount of no greater than about 0.5% by weight of the composition. In such embodiments, the ethylenediaminetetraacetate may be present in an amount of from about 0.01 to about 1 %, preferably from about 0.01 to about 0.5% by weight of the composition.

[0132] In various embodiments, the chelating agent includes a phosphate present in an amount of about 0.01 % to about 1 % by weight, an ethylenediaminetetraacetate salt present in an amount of about 0.01% to about 0.5% by weight of the composition, or a mixture thereof.

[0133] In various embodiments, the surfactant is present in the composition in an amount of from about 0.01 to about 10% by weight and the chelating agent is present in the composition in an amount of from about 0.01 to about 10% by weight, both based on the total weight of the composition. In preferred embodiments, the surfactant is present in the composition in an amount of from about 0.01 to about 5% by weight and the chelating agent is present in the composition in an amount of from about 0.01 to about 5% by weight, both based on the total weight of the composition. In such embodiments, the surfactant may be selected from sarcosinates, glutamates, isethionates, amphoacetates, amphodiacetates, betaines, amidoalkylbetaines, polysorbates, sulfates. In preferred embodiments wherein the surfactant is selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, the surfactant is more preferably selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof. In other preferred embodiments, the surfactant is selected from glutamates, sarcosinates, isethionates and sulfates and mixtures thereof. Also preferred are polysorbate surfactants. In preferred embodiments wherein the surfactant is selected from amphoacetates and amidoalkylbetaines, the surfactant is more preferably be selected from a fatty acid amphoacetate or fatty acid amidoalkylbetaine wherein the fatty acid comprises 8 to 24 carbon atoms. The chelating agent may be selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixturesthereof. Preferred are EDTA salts such as tetrasodium EDTA and phosphate salts such as disodium phosphate.

[0134] In various embodiments, the surfactant is present in the composition in an amount of from about 0.01 to about 5% by weight based on the total weight of the composition and the chelating agent includes a phosphate present in an amount of about 0.01 % to about 1% by weight an ethylenediaminetetraacetate salt present in an amount of about 0.01 % to about 0.5% by weight of the composition, or a mixture thereof. In such embodiments, the surfactant may be selected from sarcosinates, glutamates, isethionates, amphoacetates, amphodiacetates, betaines, amidoalkylbetaines, polysorbates, sulfates. In preferred embodiments wherein the surfactant is selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, the surfactant is more preferably selected from fatty acid sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, wherein the fatty acid has 8 to 24 carbon atoms. Particularly preferred are a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof. In other preferred embodiments, the surfactant is selected from glutamates, sarcosinates, isethionates and sulfates and mixtures thereof. Also preferred are polysorbate surfactants. In preferred embodiments wherein the surfactant is selected from amphoacetates and amidoalkylbetaines, the surfactant is more preferably be selected from a fatty acid amphoacetate or fatty acid amidoalkylbetaine wherein the fatty acid comprises 8 to 24 carbon atoms. The chelating agent may be selected from the group consisting of a citrate salt, a phosphate salt, an ethylenediaminetetraacetate salt, and mixtures thereof. Preferred are EDTA salts such as tetrasodium EDTA and phosphate salts such as disodium phosphate.

[0135] The weight ratio of chelating agent to surfactant may be controlled in order to further enhance the advantageous properties of the wound cleansing composition. In various embodiments the weight ratio of chelating agent to surfactant is about 10:1 to about 1 :10. In preferred embodiments the weight ratio of chelating agent to surfactant is about 5:1 to about 1 :5. In particularly preferred embodiments the weight ratio is about 4:1 to about 1 :1.

[0136] In various embodiments, the composition comprises from about 10 ppm to about 50 ppm, from about 10 ppm to about 100 ppm, from about 10 ppm to about 150 ppm, or from about 10 ppm to about 200 ppm hypochlorous acid, and the weight ratio of chelating agent to surfactant is about 10:1 to about 1 :10, preferably about 5:1 to about 1 :5, more preferably about 4:1 to about 1 :1.

[0137] Thus, in various embodiments, the weight ratio of hypochlorous acid to chelating agent to surfactant may be controlled to enhance the advantageous properties of the wound cleansing composition. In preferred embodiments, the weight ratio of hypochlorous acid to chelating agent to surfactant (HOCkchelating agent: surfactant) is about 1 :100:1000 to about 1 :1000:100, or from about 20: 100: 1000 to about 20: 1000: 100. In more preferred embodiments, the weight ratio of hypochlorous acid to chelating agent to surfactant (HOCkchelating agentsurfactant) is about 1 :100:500 to about 1 :500:100, or from about 20:100:500 to about 20:500:100.Aqueous solvent / composition

[0138] In various embodiments, the wound cleansing composition is a liquid wound cleansing composition. The compositions described herein will typically used to irrigate and / or cleanse a wound, for example as an initial treatment in first aid, or during wound management, such as between changes of wound dressing. Typically, such applications require high efficacy in a short contact time - for instance, the composition may be applied to the wound for less than about 15 minutes, or less than about 10 minutes. This contrasts with other compositions known in the art that may be comprised in wound dressings and the like that may have a lower efficacy and act by controlled release over several days or weeks. In various embodiments the liquid composition does not include gels, pastes and emulsions.

[0139] In various embodiments, the solvent of the compositions described herein fully solubilises the surfactant and chelating agent, i.e. such compositions are not emulsions or suspensions. The solvent is an aqueous solvent and is present in an amount of at least about 50% by weight of the composition. In various embodiments, the solvent may be water.

[0140] In various embodiments, the wound cleansing composition is aqueous. By the term “aqueous” is meant that the composition includes water in an amount of at least about 50% by weight of the composition.

[0141] In other embodiments, the solvent may comprise a buffering agent. Buffering agents are commonly known to a person of skill in the art of the present disclosure, who will be able to select appropriate buffering agents as part of their common general knowledge. For instance, the buffering agent may be selected to be suitable for a desired pH range and / or physiological compatibility, e.g. with human tissue. In some embodiments, the chelating agent also acts as a buffering agent. Accordingly, in some embodiments the composition does notcomprise a buffering agent other than the chelating agent. The hypochlorous acid is not considered to form a buffering agent within the meaning of the present disclosure.

[0142] The aqueous solvent (e.g. water) may be present in an amount of at least about 60%, such as about 70%, or even at least about 80% by weight of the composition.

[0143] In the first to third aspects, the pH of the composition of the present disclosure is not limited. However, in preferred embodiments, the pH of the composition is from about 5 to about 9. In various embodiments, the pH of the composition is from about 5 to about 8. In various embodiments, the pH of the composition is from about 6 to about 8. Compositions within said range of pH values may cause less discomfort upon application, for example from stinging sensations. In some embodiments, it has been surprisingly found that a mildly alkaline pH, for example about pH 8 may enhance the efficacy of the wound cleansing composition.

[0144] The chlorine species discussed above in respect of Scheme 1 , including HOCI, are pH dependent, and the relative proportion of such species thus depends on the pH of the solution. Thus, in the fourth to sixth aspects of the present disclosure, the pH of the wound cleansing composition is from about 4 to about 8, preferably from about 5 to about 8, more preferably from about 6 to about 8. In various embodiments, the pH of the wound cleansing composition is from about 4 to about 6.5, preferably from about 5 to about 6.5.

[0145] As discussed herein, the present inventors have discovered that the combinations of surfactant and chelating agent as defined herein help stabilise the hypochlorous acid, e.g. by minimising the change in the pH of the composition over time. As defined herein above, “stability” and “shelf-life” may be used interchangeably, and should be understood to refer to minimising the change in pH over time of the composition of the present disclosure; particularly during storage. For example, in various embodiments, “stable” means that the pH of the composition may not change by more than ±2 pH, preferably ±1 pH, when the composition is stored for a given period of time. The composition may be stable for at least 3 months, preferably at least 6 months, more preferably at least 12 months. A person skilled in the art of the present disclosure will be able to select suitable storage conditions. For instance, the composition may be stored at ambient temperature (e.g. around 20°C), or preferably at around 5°C. Thus, in various embodiments, the compositions described herein are stored at temperatures less than about 20°C, preferably less than about 10°C, more preferably less than about 5°C. The composition is preferably stored in a dark, sealed container, the nature and material of which are not critical. For example, a dark polyethylene terephthalate (PET) or other moisture resistant plastic container may be used.Methods and Uses of a Wound Cleansing Composition

[0146] As described herein, the compositions of the present disclosure are useful for the treatment of wounds, including initial treatment in first response settings, as well as in ongoing wound management such as in primary care settings. Accordingly, the present disclosure provides for the use of any of the compositions described herein in treating a wound. The compositions described herein may be used in cleansing and / or irrigating a wound.

[0147] As used herein the expression "wound" includes an injury to living tissue and may be caused by a cut, blow, or other impact, abrasion, pressure, heat or chemical. Typically the wound is one in which the skin is cut or broken. A wound is often described as chronic or acute. Acute wounds occur as a result of surgery or trauma, typically when not too severe and where the subject is otherwise in good health. Wounds progress through well-defined stages of healing. Chronic wounds begin as acute wounds. For example, 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 can be due to an inadequate immune response, for example the patient being immuno-compromised, the wound being insufficiently perfused or being highly contaminated. Chronic wounds may include venous ulcers, diabetic ulcers, arterial ulcers, and pressure injuries due to immobility. Wounds may also include a deep tissue injury; this is an expression used to describe a unique form of pressure ulcers.

[0148] To cleanse a wound means to use fluid to remove loosely adherent debris and necrotic tissue from the wound surface. A wound cleanser may be an aid in debridement - removing deeply adherent, dead or contaminated tissue from a wound - but a debridement solution is not a wound cleanser. Dakin’s solution, a buffered 0.5 percent solution of sodium or potassium hypochlorite, is for example a debridement agent rather than a cleansing one because it is injurious to tissues. A desirable wound cleanser should be biocompatible and physiologically compatible with the body tissue. Wound irrigation is the act of flushing a wound with a stream or flow of a solution across an open wound surface. A wound cleanser may also provide additional benefits such as moisturising, which may occur during irrigating or rinsing a wound with the cleanser.

[0149] As described herein, the compositions of the present disclosure disrupt and lift the loose components of wounds from the surface. Surprisingly the compositions further disrupt one or more biofilms. The latter is advantageous because the presence of microbes in woundsis an additional and common impediment to the healing of wounds and can lead to clinical complications.

[0150] Compositions including hypochlorous acid also kill the microbes present in the wound and / or one or more biofilms. Advantageously, the compositions achieve this killing through the combined action of the surfactant, chelating agent and hypochlorous acid. In particular, the use of hypochlorous acid is advantageous over existing solutions such as Dakin’s solution because hypochlorous acid has a higher antimicrobial efficacy by weight and is also more biocompatible (e.g. with tissues) than hypochlorite. Other advantages may include reduced odour e.g. compared to hypochlorite and / or chlorine-based solutions, and / or reduced discomfort associated with application of the solution.

[0151] As used herein, “microbe” means bacteria, protozoa, funghi, algae, amoeba, and slime molds. The term “bacteria” (and derivatives thereof, such as “microbial infection") includes, but is not limited to, references to organisms (or infections due to organisms) of the following classes and specific types:

[0152] Gram-positive cocci, such as Staphylococci (e.g. Staph, aureus, Staph, epidermidis, Staph, saprophyticus, Staph, auricularis, Staph, capitis capitis, Staph, c. ureolyticus, Staph, caprae, Staph, cohnii cohnii, Staph, c. urealyticus, Staph, equorum, Staph, gallinarum, Staph, haemolyticus, Staph, hominis hominis, Staph, h. novobiosepticius, Staph, hyicus, Staph, intermedius, Staph, lugdunensis, Staph, pasteuri, Staph, saccharolyticus, Staph, schleiferi schleiferi, Staph, s. coagulans, Staph, sciuri, Staph, simulans, Staph, warned and Staph, xylosus , Streptococci (e.g. beta-haemolytic, pyogenic streptococci (such as Strept. agalactiae, Strept. canis, Strept. dysgalactiae dysgalactiae, Strept. dysgalactiae equisimilis, Strept. equi equi, Strept. equi zooepidemicus, Strept. iniae, Strept. porcinus and Strept. pyogenes), microaerophilic, pyogenic streptococci (Streptococcus “milleri”, such as Strept. anginosus, Strept. constellatus constellatus, Strept. constellatus pharyngidis and Strept. intermedius), oral streptococci of the “mitis” (alpha-haemolytic - Streptococcus “viridans”, such as Strept. mitis, Strept. oralis, Strept. sanguinis, Strept. cristatus, Strept. gordonii and Strept. parasanguinis), “salivarius” (non-haemolytic, such as Strept. salivarius and Strept. vestibularis) and “mutans” (tooth-surface streptococci, such as Strept. criceti, Strept. mutans, Strept. ratti and Strept. sobrinus) groups, Strept. acidominimus, Strept. bovis, Strept. faecalis, Strept. equinus, Strept. pneumoniae and Strept. suis, or Streptococci alternatively classified as Group A, B, C, D, E, G, L, P, II or V Streptococcus);

[0153] Gram-negative cocci, such as Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria cinerea, Neisseria elongata, Neisseria flavescens, Neisseria lactamica, Neisseria mucosa, Neisseria sicca, Neisseria subflava and Neisseria weaverr, Bacillaceae, such as Bacillus anthracis, Bacillus subtilis, Bacillus thuringiensis, Bacillus stearothermophilus and Bacillus cereus', Enterobacteriaceae, such as Escherichia coli, Enterobacter (e.g. Enterobacter aerogenes, Enterobacter agglomerans and Enterobacter cloacae), Citrobacter (such as Citrob. freundii and Citrob. divernis), Hafnia (e.g. Hafnia alvei), Erwinia (e.g. Erwinia persicinus), Morganella morganii, Salmonella (Salmonella enterica and Salmonella typhi), Shigella (e.g. Shigella dysenteriae, Shigella flexneri, Shigella boydii and Shigella sonnei), Klebsiella (e.g. Klebs, pneumoniae, Klebs, oxytoca, Klebs, ornitholytica, Klebs, planticola, Klebs, ozaenae, Klebs, terrigena, Klebs, granulomatis (Calymmatobacterium granulomatis) and Klebs, rhinoscleromatis), Proteus (e.g. Pr. mirabilis, Pr. rettgeri and Pr. vulgaris), Providencia (e.g. Providencia alcalifaciens, Providencia rettgeri and Providencia stuartii), Serratia (e.g. Serratia marcescens and Serratia liquifaciens), and Yersinia (e.g. Yersinia enterocolitica, Yersinia pestis and Yersinia pseudotuberculosis)', Enterococci (e.g. Enterococcus avium, Enterococcus casseliflavus, Enterococcus cecorum, Enterococcus dispar, Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Enterococcus flavescens, Enterococcus gallinarum, Enterococcus hirae, Enterococcus malodoratus, Enterococcus mundtii, Enterococcus pseudoavium, Enterococcus raffinosus and Enterococcus solitarius)', Helicobacter (e.g. Helicobacter pylori, Helicobacter cinaedi and Helicobacter fennelliae)', Acinetobacter (e.g. A. baumanii, A. calcoaceticus, A. haemolyticus, A. johnsonii, A. junii, A. Iwoffi and A. radioresistens)', Pseudomonas (e.g. Ps. aeruginosa, Ps. maltophilia (Stenotrophomonas maltophilia), Ps. alcaligenes, Ps. chlororaphis, Ps. fluorescens, Ps. luteola. Ps. mendocina, Ps. monteilii, Ps. oryzihabitans, Ps. pertocinogena, Ps. pseudalcaligenes, Ps. putida and Ps. stutzeri)', Bacteriodes fragilis', Peptococcus (e.g. Peptococcus niger)', Peptostreptococcus; Clostridium (e.g. C. perfringens, C. difficile, C. botulinum, C. tetani, C. absonum, C. argentinense, C. baratii, C. bifermentans, C. beijerinckii, C. butyricum, C. cadaveris, C. carnis, C. celatum, C. clostridioforme, C. cochlearium, C. cocleatum, C. fallax, C. ghonii, C. glycolicum, C. haemolyticum, C. hastiforme, C. histolyticum, C. indolis, C. innocuum, C. irregulare, C. leptum, C. limosum, C. ma / enominatum, C. novyi, C. oroticum, C. paraputrificum, C. piliforme, C. putrefasciens, C. ramosum, C. septicum, C. sordelii, C. sphenoides, C. sporogenes, C. subterminale, C. symbiosum and C. tertium)', Mycoplasma (e.g. M. pneumoniae, M. hominis, M. genitalium and M. urealyticum)', Mycobacteria (e.g. Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium fortuitum, Mycobacterium marinum, Mycobacterium kansasii, Mycobacterium chelonae, Mycobacterium abscessus, Mycobacterium leprae, Mycobacterium smegmitis, Mycobacteriumafricanum, Mycobacterium alvei, Mycobacterium asiaticum, Mycobacterium aurum, Mycobacterium bohemicum, Mycobacterium bovis, Mycobacterium branderi, Mycobacterium brumae, Mycobacterium celatum, Mycobacterium chubense, Mycobacterium confluentis, Mycobacterium conspicuum, Mycobacterium cookii, Mycobacterium flavescens, Mycobacterium gadium, Mycobacterium gastri, Mycobacterium genavense, Mycobacterium gordonae, Mycobacterium goodii, Mycobacterium haemophilum, Mycobacterium hassicum, Mycobacterium intracellulare, Mycobacterium interjectum, Mycobacterium heidelberense, Mycobacterium lentiflavum, Mycobacterium malmoense, Mycobacterium microgenicum, Mycobacterium microti, Mycobacterium mucogenicum, Mycobacterium neoaurum, Mycobacterium nonchromogenicum, Mycobacterium peregrinum, Mycobacterium phlei, Mycobacterium scrofulaceum, Mycobacterium shimoidei, Mycobacterium simiae, Mycobacterium szulgai, Mycobacterium terrae, Mycobacterium thermoresistabile, Mycobacterium triplex, Mycobacterium triviale, Mycobacterium tusciae, Mycobacterium ulcerans, Mycobacterium vaccae, Mycobacterium wolinskyi and Mycobacterium xenopi); Haemophilus (e.g. Haemophilus influenzae, Haemophilus ducreyi, Haemophilus aegyptius, Haemophilus parainfluenzae, Haemophilus haemolyticus and Haemophilus parahaemolyticus); Actinobacillus (e.g. Actinobacillus actinomycetemcomitans, Actinobacillus equuli, Actinobacillus hominis, Actinobacillus lignieresii, Actinobacillus suis and Actinobacillus ureae Actinomyces (e.g. Actinomyces israelii)', Brucella (e.g. Brucella abortus, Brucella canis, Brucella melintensis and Brucella suis); Campylobacter (e.g. Campylobacter jejuni, Campylobacter coli, Campylobacter lari and Campylobacter fetus); Listeria monocytogenes; Vibrio (e.g. Vibrio cholerae and Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio carchariae, Vibrio fluvialis, Vibrio furnissii, Vibrio hollisae, Vibrio metschnikovii, Vibrio mimicus and Vibrio vulnificus); Erysipelothrix rhusopathiae; Corynebacteriaceae (e.g. Corynebacterium diphtheriae, Corynebacterium jeikeum and Corynebacterium urealyticum); Spirochaetaceae, such as Borrelia (e.g. Borrelia recurrentis, Borrelia burgdorferi, Borrelia afzelii, Borrelia andersonii, Borrelia bissettii, Borrelia garinii, Borrelia japonica, Borrelia lusitaniae, Borrelia tanukii, Borrelia turdi, Borrelia valaisiana, Borrelia caucasica, Borrelia crocidurae, Borrelia duttoni, Borrelia graingeri, Borrelia hermsii, Borrelia hispanica, Borrelia latyschewii, Borrelia mazzottii, Borrelia parkeri, Borrelia persica, Borrelia turicatae and Borrelia venezuelensis) and Treponema (Treponema pallidum ssp. pallidum, Treponema pallidum ssp. endemicum, Treponema pallidum ssp. pertenue and Treponema carateum); Pasteurella (e.g. Pasteurella aerogenes, Pasteurella bettyae, Pasteurella canis, Pasteurella dagmatis, Pasteurella gallinarum, Pasteurella haemolytica, Pasteurella multocida multocida, Pasteurella multocida gallicida, Pasteurella multocida septica, Pasteurella pneumotropica and Pasteurella stomatis); Bordetella (e.g. Bordetella bronchiseptica, Bordetella hinzii, Bordetella holmseii, Bordetellaparapertussis, Bordetella pertussis and Bordetella trematumy Nocardiaceae, such as Nocardia (e.g. Nocardia asteroides and Nocardia brasiliensisy Rickettsia (e.g. Ricksettsii or Coxiella burnetii)', Legionella (e.g. Legionalla anisa, Legionalla birminghamensis, Legionalla bozemanii, Legionalla cincinnatiensis, Legionalla dumoffii, Legionalla feeleii, Legionalla gormanii, Legionalla hackeliae, Legionalla israelensis, Legionalla jordanis, Legionalla lansingensis, Legionalla longbeachae, Legionalla maceachernii, Legionalla micdadei, Legionalla oakridgensis, Legionalla pneumophila, Legionalla sainthelensi, Legionalla tucsonensis and Legionalla wadsworthii Moraxella catarrhalis’, Cyclospora cayetanensis; Entamoeba histolytica; Giardia lamblia; Trichomonas vaginalis; Toxoplasma gondii; Stenotrophomonas maltophilia’, Burkholderia cepacia', Burkholderia mallei and Burkholderia pseudomallei', Francisella tularensis', Gardnerella (e.g. Gardneralla vaginalis and Gardneralla mobiluncusy Streptobacillus moniliformis', Flavobacteriaceae, such as Capnocytophaga (e.g. Capnocytophaga canimorsus, Capnocytophaga cynodegmi, Capnocytophaga gingivalis, Capnocytophaga granulosa, Capnocytophaga haemolytica, Capnocytophaga ochracea and Capnocytophaga sputigenay Bartonella (Bartonella bacilliformis, Bartonella clarridgeiae, Bartonella elizabethae, Bartonella henselae, Bartonella quintana and Bartonella vinsonii arupensisy Leptospira (e.g. Leptospira biflexa, Leptospira borgpetersenii, Leptospira inadai, Leptospira interrogans, Leptospira kirschneri, Leptospira noguchii, Leptospira santarosai and Leptospira weilii Spirillium (e.g. Spirillum minus)’, Baceteroides (e.g. Bacteroides caccae, Bacteroides capillosus, Bacteroides coagulans, Bacteroides distasonis, Bacteroides eggerthii, Bacteroides forsythus, Bacteroides fragilis, Bacteroides merdae, Bacteroides ovatus, Bacteroides putredinis, Bacteroides pyogenes, Bacteroides splanchinicus, Bacteroides stercoris, Bacteroides tectus, Bacteroides thetaiotaomicron, Bacteroides uniformis, Bacteroides ureolyticus and Bacteroides vulgatusy Prevotella (e.g. Prevotella bivia, Prevotella buccae, Prevotella corporis, Prevotella dentalis (Mitsuokella dentalis), Prevotella denticola, Prevotella disiens, Prevotella enoeca, Prevotella heparinolytica, Prevotella intermedia, Prevotella loeschii, Prevotella melaninogenica, Prevotella nigrescens, Prevotella oralis, Prevotella oris, Prevotella oulora, Prevotella tannerae, Prevotella venoralis and Prevotella zoogleoformansy Porphyromonas (e.g. Porphyromonas asaccharolytica, Porphyromonas cangingivalis, Porphyromonas canoris, Porphyromonas cansulci, Porphyromonas catoniae, Porphyromonas circumdentaria, Porphyromonas crevioricanis, Porphyromonas endodontalis, Porphyromonas gingivalis, Porphyromonas gingivicanis, Porphyromonas levii and Porphyromonas macacaey Fusobacterium (e.g. F. gonadiaf ormans, F. mortiferum, F. naviforme, F. necrogenes, F. necrophorum necrophorum, F. necrophorum fundiliforme, F. nucleatum nucleatum, F. nucleatum fusiforme, F. nucleatum polymorphum, F. nucleatum vincentii, F. periodonticum, F. russii, F. ulcerans and F. varium

[0154] Chlamydia (e.g. Chlamydia trachomatis)-, Cryptosporidium (e.g. C. parvum, C. hominis, C. cam's, C. felis, C. meleagridis and C. murisy Chlamydophila (e.g. Chlamydophila abortus (Chlamydia psittaci), Chlamydophila pneumoniae (Chlamydia pneumoniae) and Chlamydophila psittaci (Chlamydia psittaci))-, Leuconostoc (e.g. Leuconostoc citreum, Leuconostoc cremoris, Leuconostoc dextranicum, Leuconostoc lactis, Leuconostoc mesenteroides and Leuconostoc pseudomesenteroidesy Gemella (e.g. Gemella bergeri, Gemella haemolysans, Gemella morbillorum and Gemella sanguinis)-, and Ureaplasma (e.g. Ureaplasma parvum and Ureaplasma urealyticum).

[0155] In various embodiments, the bacterial infection is associated with Staphylococcus aureus or Pseudomonas aeruginosa. In various embodiments, the bacterial infection is caused by Staphylococcus aureus or Pseudomonas aeruginosa.

[0156] It has surprisingly been found that compositions according to the first to third aspects of the present disclosure are effective at disrupting biofilms while cleansing and / or irrigating wounds even in the absence of an antimicrobial agent. It has also surprisingly been found that compositions according to the fourth to sixth aspects of the present disclosure are effective at disrupting biofilms while cleansing and / or irrigating wounds and also kill microbes associated with wounds and / or biofilms. As used herein, “biofilm” means a syntrophic consortium of microorganisms in which cells stick to each other and optionally also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs).

[0157] Thus, in various embodiments, the wound comprises one or more biofilms, wherein “biofilm” is as defined herein. In various embodiments of the wound cleansing composition for use as described herein, the wound comprises one or more biofilms and treating the wound comprises disrupting said one or more biofilms. As used here, “disrupting” in the context of the one or more biofilms means loosening, softening, and detaching the biofilm from the wound bed.

[0158] As discussed herein, in some embodiments it may be preferable to avoid use of an antimicrobial agent, for example to avoid the risk of resistance to said antimicrobial agent, and / or due to intolerance to the antimicrobial agent in the subject whose wound is to be treated. Wound cleansers that do not contain antimicrobial agents may also be preferable in certain applications because they may not be classed as medicaments.

[0159] Thus, in various embodiments the compositions of the present disclosure are nonantimicrobial. For instance, in various embodiments the compositions of the present disclosure do not comprise an antimicrobial agent. The antimicrobial agent is not limited and includes silver compounds, hypochlorous acid, polyhexamethylene biguanide (also known as polyhexanide biguanide), chlorhexidine and salts thereof.

[0160] The generally accepted criterion for an antimicrobial cleanser solution is a 3-log10 reduction in microbial cell number in a given contact time period. Thus, in various embodiments, the non-antimicrobial wound cleansing compositions described herein cause less than about a 3-log10 reduction in the number of microbial cells in the wound when contacted with the wound for about 10 minutes. Preferably, the non-antimicrobial wound cleansing compositions described herein cause less than about a 2-log10 reduction in the number of microbial cells in the wound when contacted with the wound for about 10 minutes. More preferably, the non-antimicrobial wound cleansing compositions described herein cause less than about a 1-log10 reduction in the number of microbial cells in the wound when contacted with the wound for about 10 minutes.

[0161] The wound cleansing compositions of the fourth to sixth aspects of the present disclosure may be described as being antimicrobial. The generally accepted criterion for an antimicrobial cleanser solution is a 3-log 10 reduction in microbial cell number in a given contact time period. Thus, in various embodiments, the wound cleansing compositions described herein cause greater than about a 3-log10 reduction in the number of microbial cells in the wound when contacted with the wound for about 10 minutes. In preferable embodiments, the wound cleansing compositions described herein cause greater than about a 4-log10 reduction in the number of microbial cells in the wound when contacted with the wound for about 10 minutes. In further preferable embodiments, the wound cleansing compositions described herein cause greater than about a 5-log10 reduction in the number of microbial cells in the wound when contacted with the wound for about 10 minutes. Thus, in various embodiments the wound cleansing compositions described herein may be used to kill microbial cells in the wound. In any of these embodiments, the microbial cells in the wound may be comprised in one or more biofilms. In various embodiments, the microbial cells in the wound are bacteria, e.g. as defined herein above. Wound cleansing solutions with any of the antimicrobial activities described above may in some embodiments be described as wound disinfectants. Thus, in some embodiments the compositions described herein may be used to disinfect a wound. As described above, the wound may comprise one or more biofilms.

[0162] The compositions of the present invention may be in the form of a solution which can be used as a spray to be applied to cleaning materials or directly to the wound or a solution dip in to which cleaning materials can be immersed. Alternatively, the compositions can be in the form of a foam or a mousse. The compositions of the present invention may be supplied in a bottle for irrigation, or in a pressurised canister or mechanical pump system that uses jet pressure to enhance mechanical debridement. In other embodiments, the compositions may be supplied as a soft spray to ensure thorough application, as a solution pre-soaked into a debridement wipe, sponge, or cloth. The compositions may be used in the form of a compress, for example soaked into a gauze, alginate or AQUACEL® (hydrofibre) dressing. In various embodiments, the compositions may be thickened with a thickening agent. Exemplary thickening agents include gums, polysaccharides such as starch, agar, carboxymethylcellulose, hydroxyethylcellulose, gelatin, pectin, chitosan, alginate, clay, synthetic thickeners such as polyethylene glycols, poloxamers (as defined herein above), polyvinyl alcohol / acetate, polyvinylpyrrolidone, polyacrylates, silicates / silica, carbomers. Any of the preceding forms may alternatively be prepared extemporaneously, e.g. by a clinician, healthcare practitioner, or pharmacist. In various embodiments, the compositions may be supplied as a concentrate for dilution, e.g. prior to application in a care setting, such as in a bath or bucket for application.

[0163] The compositions of the present invention are advantageous for the treatment of all wounds. Wounds suitable for treatment may, for example, be acute, surgical, or traumatic wounds. Such wounds may be irrigated by the compositions of the present invention to remove contamination and debris, and to clean the surrounding skin so that suitable dressings may be applied. Throughout the entire healing pathway, wounds may be cleansed e.g. between dressing changes, to remove excess exudates, debris, non-viable tissues, and to reduce the surface / skin bioburden (e.g. bacteria, thereby reducing infection risk). The composition of the present invention may be used to cleanse a wound that appears to be on a healing pathway in order to prevent opportunistic pathogens from forming biofilm. Cleansing with the compositions of the present invention is particularly advantageous after debridement. Wound cleansing may also be performed to assist appropriate inspection and diagnosis. Cleansing with the compositions of the present invention is particularly advantageous for the treatment of long-standing, non-healing, so-called chronic wounds.

[0164] In various embodiments, the compositions of the present invention do not contain further components other than those already described above. In such embodiments, the compositions are preferably supplied as a sterile solution, e.g. wherein such solutions areprepared from sterilised components in a sterile environment, or wherein the final solution is sterilised by methods commonly known in the art. In alternative embodiments, the compositions of the present invention may comprise one or more additional components selected from preservatives, anti-oxidants, osmotic adjusters and surfactants. Suitable preservatives are known in the art, such as polyhexamethylene biguanide (PHMB). Preservatives may advantageously have a mild bacteriostatic effect in the wound. Antioxidants are also well known and a person skilled in the art of the present invention will be able to select suitable anti-oxidants. Anti-oxidants may advantageously aid preservation and reduce the prevalence of reactive oxygen species in the wound environment that are typically elevated in chronically inflamed wounds and associated with retarded healing. Osmotic adjusters may be included in the solutions of the present invention to adjust the tonicity (ionic strength) of said compositions. For example, pain can be minimised by the use of isotonic compositions (i.e. having an osmolality similar to plasma). Plasma osmolality typically falls within 0.285 to 0.300 Osmol / kg. Alternatively, hypotonic (i.e. having an osmolality less than plasma) compositions may be advantageous to increase surfactancy potential. Conversely, hypertonic (i.e. having an osmolality greather than plasma) solutions may confer bactericidal effects that may be advantageous in various applications. The skilled person will be able to select suitable osmotic adjusters and obtain a desired tonicity as a matter of routine. In various embodiments, the wound cleansing composition is an isotonic or hypertonic solution. In various embodiments, one or more surfactants in addition to those described above may be included, e.g. as “secondary surfactants” to boost the primary surfactant as described above. Such secondary surfactants may be any of the surfactants described hereinabove, but do not include cationic surfactants. The wound cleansing composition may have a surface tension of less than about 35 mN / m to facilitate loosening and cleansing.

[0165] Having generally described this disclosure, a further understanding can be obtained by reference to certain specific examples illustrated below which are provided for purposes of illustration only and are not intended to be all inclusive or limiting unless otherwise specified.ExamplesEXPERIMENTAL 1 :Materials and MethodsCombination solution preparationSurfactant test solutions were made up in deionised water. The final concentrations were made up from liquids with known purity according to Equation 1 .To the surfactant solution was added chelating agent at the required concentration. For hydrated solids, the hydration coefficient was calculated according to Equation 2 where RMM is the relative molecular mass.RMM of hydrate g / mol)- - - - — - - - — - - — = hydration coefficient 2 RMM of anhydrous g / moi)The required mass of chelating agent was then calculated according to Equation 3, where the theoretical mass is the mass that would be required for the anhydrous solid.Mass required (g) = theoretical mass (g) x hydration coefficient 3Where necessary, solutions were gently heated with constant stirring to facilitate dissolution. If required, the pH of solutions was adjusted via the dropwise addition of 2 M HCI aqueous solution.Solution characterisationSolubility: Visual assessments were performed on both the individual surfactant solutions and combination solutions. pH: The pH of aqueous dispersions of each test formulation was measured using a pH electrode according to standard methods in the art.Surface Tension:Combination solutions that remained fully dissolved after 6 days visual assessment were evaluated for surface tension using a SITA Proline bubble pressure tensiometer. The instrument was calibrated with deionised water prior to use, and single measurements takenof each solution via submersion of both temperature probe and bubble capillary into the bulk solution.Osmolality: Stable combination solutions were also evaluated for osmolality using an automatic cryoscopic osmometer. The instrument was calibrated with purified deionised water and 300 mOsmol / kg NaCI.Simulated bio film model:Loosening of simulated biofilm material by cleanser combinations was performed using a ‘disk model’ method that measures the ability of test formulations to degrade an artificial substance designed to mimic biofilm and slough. While reference is made herein below to ‘debridement testing’ and ‘debridement activity’, it should be understood that ‘debridement’ as assessed by the simulated biofilm model includes wound cleansing properties, anti-biofilm activity, debridement-enhancing properties, the promotion of autolytic debridement and / or direct debridement, as described in more detail herein above. The composition of the artificial substance is as shown in the following table.The proteins, polysaccharides, and water mimic the hydrated EPS matrix found in biofilm, and the deactivated yeast represents the cellular debris present in inflammatory wounds. Crystal violet was incorporated into the substrate to enable the quantification of debridement.To prepare the simulated biofilm / non-viable matter for debridement testing, 100 ml of liquid substrate was warmed to room temperature and spread across an acetate sheet to a thickness of 1.5 mm. The substrate film was soaked in 1.5% w / w calcium chloride solution for 18 ± 2 hours. This enabled calcium ions to penetrate and bind to the alginate polymers in the substrate, causing gelation. This mimicked the ionic bridging between divalent cations and EPS polymers in biofilm. The substrate gel was removed from the calcium chloride and rinsedwith deionised water. Substrate samples were prepared using a hole-borer to cut discs 1.2 cm in diameter.Figure 9 illustrates the assay used to test solutions for debridement activity. 2 ml of each test solution were added to glass scintillation vials and warmed to 37°C. One substrate disc was added to each warmed solution before incubating the vials at 37°C for 10 minutes. After incubation, the solutions were homogenised on a roller mixer for 3 minutes. 1 ml samples from each solution were centrifuged at 10,000 RPM for 5 minutes to remove any precipitate or substrate residue. 200 pL of supernatant from each sample were added to wells of a 96-well plate. A microplate reader was used to measure the absorbance of the samples at 595nm. The degradation of the substrate was proportional to the amount of crystal violet that leached into the test solution. Therefore, higher absorbance values reflected higher debridement activity. Z-values were calculated by dividing the blank-corrected mean absorbance value of the test substance by that of the positive control. In all cases, Prontosan irrigation solution (B. Braun) was used as a positive control. 0.9% w / w Saline was the negative control and H2O was used for blank-correction.Design of experimentsExperiments designed to test the range and effect of excipient concentration were conducted and evaluated according to disruption of simulated biofilm (Z value). A full factorial analysis was performed to analyse the relationship between excipient concentration and response output. The factorial analysis consisted of 3 factors ([surfactant], [chelator] and pH) and 2 levels (high, low). A factorial analysis assumes a linear relationship between each x and y and uses a first order regression model. In order to detect any deviation from linearity, center points were included (mid-range concentrations, n = 3). The upper and lower concentration limits were determined from preliminary data taking into account efficacy, solubility and predicted safety / biocompatibility. Table 1 details the experiments undertaken in the factorial analysis.Table 1 : Formulations used for factorial analysisThis matrix was applied to each combination of surfactant / chelator.Biological evaluation: anti-biofilm activityCleanser solutions were evaluated for anti-biofilm activity with a 10-minute contact time. Briefly, serial dilutions of each combination were performed across a 96-well plate and challenged with 24-hour biofilms of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). Minimum biofilm eradication concentration was determined via optical density measurements (595nm) and total viable cell counts.Results and DiscussionSolution propertiesInitial testing was undertaken to assess the following solution properties: solubility, pH, surface tension and osmolality. Since it is desirable that the formulated wound cleanser works quickly to remove biofilm and debris from a wound bed, the evaluated concentrations were in the range 1-10% w / w.Solutions were made up as every different combination of each surfactant / cleanser at each of the different 4 nominated concentrations, resulting in 256 individual solutions in total. The solutions that remained stable after 6 days visual evaluation were assessed for pH, surface tension and osmolality. Results can be found in Figures 1-3 respectively. All solutions of disodium lauryl sulfosuccinate were insoluble and therefore discounted from further consideration.Preferably, solutions would have a pH of 5-9 (hence pH being unlikely to cause cytotoxic effects), a low surface tension (to facilitate loosening and cleansing), and an osmolality of <0.4Osmol / kg (i.e. isotonic to mildly hypertonic - again for reasons of low / no cell toxicity). Plasma osmolality typically falls at 0.285-0.300 Osmol / kg, thus the osmolality parameter was set to prevent a painful or burning sensation upon application to the skin. A hypotonic solution (defined as an osmolality of <0.284) is, however, still suitable because this is easily modified via dissolution in different media (e.g. saline or buffer). Furthermore, a pH initially outside the desired range can still be suitable because the pH of such solutions can be manually adjusted using 2 M HCI solution. The results of this evaluation are shown in Table 2.Table 2: Evaluation of solution characteristics based on solubility (surfactant and chelator should preferably remain stable in solution), surface tension (preferably as low as possible), pH (preferably between 5-9 or adjustable to within this range), and osmolality (preferably <0.4 Osmol / kg to minimise pain upon application to skin).Efficacy testing (simulated bio film model)Prior to efficacy testing, the pH of the solutions were adjusted to fall between the range of 5-9 (where necessary). Any solution possessing a pH of >9 was adjusted down to fall within the acceptable range using 2 M HCI aqueous solution. Subsequent impact of this on the solution’s osmolality was evaluated via re-measurement immediately following pH adjustment. All solutions were then evaluated for efficacy using the simulated biofilm model, where Z value was calculated relative to Prontosan. Prontosan is commercially available from B. Braun and is a wound irrigation solution used for cleansing, rinsing and moisturising acute and chronic skin wounds. Adjusted solution properties Z values of each solution are shown in Table 3.Additional positive controls Actolind, Octenilin and saline (frequently used in the clinic for wound cleansing) was also assessed in this model alongside solutions according to the presentdisclosure. Actolind and Octenilin are commercially available from Acto Pharma and Schulke & Mayr GmbH respectively.Table 3: Evaluation using the modified simulated biofilm model. Adjusted pH and subsequent adjusted osmolality values are shown in brackets. Z values for all solutions were calculated against Prontosan as a positive control.As can be seen from the results shown in Table 3, all the solutions according to the present disclosure had an efficacy (Z value relative to Prontosan) greater than the positive controls, and therefore exhibit improved anti-biofilm activity compared to existing commercial solutions. These Z values are also shown in Figure 4. In some embodiments, average Z values >30 are considered particularly advantageous, for example the combinations of surfactant and chelating agent shown in Table 4.Table 4: Combinations of surfactant and chelator having average Z values >30 in efficacy testing.Based on preliminary testing, a full factorial plot was designed in order to evaluate the effect of cleanser combination concentrations (surfactant and chelator), and pH on efficacy. The design and experimental detail for this plot can be found in Experimental 2 below. A factorial design allows the study of multiple factors on a response via the variation of all factors at the same time. This allows the assessment of the interactions between the factors themselves as well as their overall effect on the response.In total, 44 different cleanser combinations at low, high or mid-point concentrations at 3 different pHs were made up and evaluated according to their ability to disrupt simulated biofilms (as described herein). Using Minitab statistical software, properties of potential cleaners were evaluated within the following pre-defined limits:Surfactant concentration: 0.5-2.0% w / wChelator concentration: 0.1-2.0% w / w pH: 5-9The absolute values of the standardised effects (from largest to smallest) are shown in Figure 5. These pareto charts allow determination of the magnitude and importance of the effects both individually and in combination. In all cleanser combination formulations, both chelator concentration, and chelator concentration in combination with pH showed a significant effect on removal of simulated biofilm material. Without wishing to be bound by theory, the sensitivity of chelation to solution pH was expected, since chelation is an equilibrium reaction, thus any species that may interact with any other species in the system may disrupt the equilibrium. Inthe case of pH, hydrogen ions may be such a factor, rendering the properties and efficacy of the bulk solution responsive to changes in pH.Using statistical modelling, the concentrations deemed to be the most effective at disrupting the simulated non-viable biofilm matrix were identified (Table 5).Table 5:The ranges were determined according to box plots, following the fixing of individual excipient concentrations at predicted nominal values (Figure 6). The cube plots support the information gained by the pareto charts; a greater chelator concentration at a higher pH causes the largest effect on Z value. Since the highest observed Z values were 2% / 2% w / w surfactant / chelator for all combinations, this suggests a degree of synergy between the two components.Round 4 combination testing: microbiological evaluationThe nominal concentrations of the four cleanser combinations listed in Table 5 were assessed for anti-biofilm activity. Activity was assessed against pathogenic bacterial species S. aureus and P. aeruginosa, which are known to cause chronic, recalcitrant infections. The generally accepted criterium for an antimicrobial cleanser solution is a 3-log reduction in a given contact time period. Thus, for a non-antimicrobial cleanser, the solutions evaluated must not cause >3- log reduction in cell viability over the 10-minute contact time.Optical density (OD) measurements (Figure 7) and total viable counts (TVCs) (Figure 8) were performed to assess for antimicrobial activity of test solutions at gradually decreasing concentration.For P. aeruginosa, both OD and TVC results are in agreement, and all 4 solution combinations do not show antimicrobial activity in comparison to the positive control (no treatment). The reduced growth seen at the higher concentrations for solutions A and B are not sufficient to result in the >3 log reduction required for antimicrobial claims. For S. aureus, growth of the bacterial biofilm was insufficient to draw significant conclusions from (103CFU is an insufficient starting cell density for biofilm evaluation).ConclusionThe formulations tested according to the present disclosure demonstrate enhanced efficacy when compared to existing commercial cleanser solutions such as Prontosan and saline. The formulations according to the present disclosure are shown in the data above to be capable of disrupting and lifting simulated wound components. Accordingly they are particularly advantageous as wound cleansing compositions.EXPERIMENTAL 2:MethodsPreparation of cleanser solutionsFour combinations as shown in Table 6 were selected for further testing. Solutions containing these surfactants and chelating agents were produced at the desired concentrations.Table 6: Surfactant / chelator combinations selected for further testingSurfactant solutions of the required concentrations were made up as described herein. When needed, solution pH was adjusted via dropwise addition of < 2M HCI or < 1M NaOH.In vitro assessmentThe debridement activity of candidate formulations was assessed using the in vitro simulated biofilm assay described hereinabove.Design of experimentsAs noted above in Experimental 1 , full-factorial design of experiments was employed to evaluate the cleanser formulations for maximum efficacy. This design was used to determine any major factors and factor interactions influencing activity. The factorial analysis consisted of 3 factors (surfactant concentration, chelator concentration, and pH) and two levels (upper, lower). This design creates experimental points using all the possible combinations of the two extreme levels of the 3 factors. Table 7 shows the upper and lower levels for each of the 3 factors. These were derived from previous data by taking into account efficacy, solubility, andpredicted biocompatibility. To detect any non-linear relationships between the factors, 3 centrepoints were included (1.25% w / w chelator, 1.05% w / w surfactant, and pH 7).Table 7: The factors and factor levels used in the full-factorial analysisThe response output was measured using the disc assay described herein. All experimental designs and data analysis were performed using Minitab software.Assessment of synergyOnce a formulation from full-factorial analysis had been identified, synergy between the surfactant and chelator was assessed. This determined whether the surfactant and chelator in combination produced a response that was greater than the sum of their individual efficacies.Synergy was tested using an adapted checkerboard assay, which is a standard method used to assess synergy of antimicrobial combinations. This assay quantifies synergy by calculating the fractional inhibitory concentration index (ZFIC) of the combination according to Equation (4). A and B are the minimum inhibitory concentrations (MIC) of each antimicrobial in combination and MICA and MlCs are the MIC of each drug individually. The MIC is defined as the lowest concentration of antimicrobial required to inhibit visible bacterial growth (15). FICA and FlCs are the fractional inhibitory concentrations of each drug. An FIC of < 0.5, 0.5 - 4.0, or > 4.0 indicates a synergistic, additive, or antagonistic relationship, respectively.64 combination solutions of varying concentrations were produced and subsequently tested using the disc assay described herein. The solutions were adjusted to the optimum pH according to the results of the full-factorial analysis. Prior to measuring absorbance, samples were added to a 96-well plate such that surfactant concentration decreased 2-fold across columns 1-7, and chelator concentration decreased 2-fold down rows A-G. Column 8 and row H contained only chelator and surfactant, respectively. Synergy was assessed by visual inspection of the plate and by comparing Z-values of each component alone and incombination. 0.9% w / w saline was the negative control. Actolind irrigation solution was also tested to compare efficacy with the combination solutions of the present disclosure.ResultsFor each of the four test combinations, chelator concentration, and the interaction between chelator concentration and pH, significantly influenced activity. Figure 5 shows Pareto plots for each combination, which display the absolute values of the standardised effects of each factor and factor interaction. Any bar that extends beyond the dashed reference line represents a statistically significant effect (P > 0.05). pH alone was a significant factor in all combinations except combination B; activity generally increased with increasing pH. Surfactant concentration alone was only a significant factor in combination D. However, for each of the four combinations, the maximum Z-value was achieved when all three factors were at the upper level (2% / 2% w / w surfactant / chelator and pH 9). This suggested a synergistic interaction between the surfactant and chelator.Figure 6 presents cube plots showing the Z-values of all the combinations of factor levels for the three factors. The cube plots illustrate that for all combinations, the experimental runs wherein all three factors were at their upper level returned the maximum Z-value.Overall, the highest Z-value was produced with 2% sodium cocoyl glutamate and 2% tetrasodium EDTA (combination C), and pH 9. However, combination A showed the most consistent efficacy at low concentrations, with an overall mean Z-value of 10.57. The mean Z- values of combinations C, B, and D were 6.81 , 5.16, and 3.13, respectively. Because high efficacy at low solution concentrations is desirable to maximise biocompatibility, combination A (sodium lauroyl sarcosinate + tetrasodium EDTA) may nonetheless in some embodiments be preferred. As a compromise between efficacy and predicted biocompatibility, a final pH of 8 may in some embodiments be preferred.SynergyWhen both sodium lauroyl sarcosinate and EDTA were tested individually, it was revealed that neither compounds induced substrate degradation alone. However, the more concentrated combination solutions displayed marked degradation, with the highest concentration (2% w / w sodium lauroyl sarcosinate and 2% w / w tetrasodium EDTA) exhibiting a Z-value of 24.4. Because neither sodium lauroyl sarcosinate nor EDTA were active alone at any of the concentrations tested, it was not possible to derive MIC values. Thus, synergy could not be characterised by calculating the ZFIC as in a standard checkerboard test. However, it wasevident from visible inspection of the 96-well plate, and comparison of Z-values, that the two components only caused debridement when in combination.Figure 10 shows the 96-well plate after completion of the assay. The diagonal pattern of blue wells in the top-left corner, as opposed to a rectangular pattern, was characteristic of a synergistic response. Since neither the sodium lauroyl sarcosinate nor EDTA alone caused debridement within the concentrations tested, all the blue combination wells indicated synergy. Sodium lauroyl sarcosinate alone did not degrade nor alter the consistency of the substrate discs. Higher concentrations of the surfactant (1-2% w / w) encased the substrate in a white precipitate but did not appear to penetrate and alter its consistency. Higher concentrations of EDTA alone (1-2% w / w) caused partial degradation of the substrate discs. These solutions appeared blue in colour, suggesting the release of crystal violet. However, the solutions returned to colourless after centrifugation and any crystal violet became suspended in the pellet. In contrast, concentrated combination solutions remained blue after centrifugation, with no visible crystal violet suspended in the pellet.Figure 11 is a 3-dimensional surface plot showing the functional relationship between surfactant concentration, chelator concentration, and Z-value. For solutions containing 0.05% w / w of both components, the combination z-values were significantly higher than the sum of the individual Z- values. Hence synergy is observed.EXPERIMENTAL 3:Materials and Methods1. HOCI stabilityIn order to assess the compatibility of the surfactant and chelating agent with hypochlorous acid (HOCI), several assay methods were used.1.1. SpectrophometryThe Palin Test quantifies free chlorine by spectrophotometry. A reagent called DPD is oxidized in presence of free chlorine to form two possible oxidation products: a magenta coloured compound known as Wurster Dye, and a colourless imine compound:This method measures total free chlorine, but does not differentiate between the two forms of free chlorine: HOCI, and OCT. The amounts of HOCI and OCT present in solution are dependent on the pH of the solution, as can be seen from the speciation curve shown in Figure 12. It can be seen from Fig 12 that if the process pH is allowed to rise too high (e.g. above about pH 9), all free chlorine in solution will be present as OCT, yet the total free chlorine levels, as reported accurately by the DPD test, will remain the same. When small amounts of chlorine react with DPD, the magenta coloured Wurster Dye is the favoured product. The colourless imine compound is favoured when high levels of CI2 is present. This method consists of adding an amount of DPD powder mixed with acid boric to 5 mL of the solution to be analysed. The solution is then placed in a standard UV-Vis spectrophotometer and absorbance values are recorded.1.1.1 Initial calibration with Salvesan® solutionSalvesan® solution containing approximately 200 ppm (200 pg / ml) of hypochlorous acid was used. A 1 :100 dilution was identified to get an absorbance graph with well-defined peaks.The principal absorbance was at Amax = 556 nm with a second strong absorbance at 514 nm (see Figure 13).To be sure that the DPD complex does not degrade with time, the absorbance of the 1 :100 diluted solution was measured every two minutes for 10 minutes (see Figure 14). Although the curve obtained showed that the absorbance linearly decreases with time (R2=1) this was not considered significant as measurements could easily be performed within 1 to 2 minutes. If a correction was required, the absorbance decrease was 0.002 absorbance units per minute.To check the proportionality between absorbance and concentration (Linearity, Beer-Lambert Law), a series of dilutions were performed on the Salvesan® solution. The plot obtained was linear with R2=0.9997. Therefore, the absorbance of the solution is directly proportional to the concentration of free chlorine (see Figure 15).This method gives information about the evolution of absorbance and about free chlorine concentration. It does not give HOCI concentration directly, but the proportion of HOCI and CIO- can be estimated from the free chlorine data by measuring the pH of the solution and then referring to the speciation plot (see Figure 12). 1.2. pH study pH variation gives an indication about the speciation and stability of the HOCI formulation and its compatibility with the chelating agents and surfactants. A pH meter was used to check the pH every week after samples were prepared. The pH of the samples should preferably be in the ranges described herein above so as to avoid e.g. harm to skin and wound tissues and discomfort.2. Samples2.1 Products testedThree commercially available solutions: Simple Science®, Microdacyn®, and Salvesan®, all containing hypochlorous acid at different concentrations were tested. Surfactants and / or chelating agents were added to those solutions and HOCI stability was followed over time.Table 8: Commercial solutions comprising hypochlorous acid2.2 Preparation of samples with surfactants and / or chelating agentsSamples comprising Simple Science® or Microdacyn® solutions with the addition of chelating agents and / or surfactants were prepared to test compatibility with hypochlorous acid. It is important to maintain a stable pH because of the pH dependence of the concentration of hypochlorous acid.Chelating agents chosen from citric acid / tri-sodium, sodium phosphate, and sodium EDTA were then added to the samples to give a final concentration of chelating agent of 0.1 % or 1% by weight of the sample composition. The pH was adjusted where necessary to be consistent with the reported pH of the starting commercial solutions (e.g. pH 6.2 for Microdacyn® and pH7.2 for Simple Science®).Then buffer solutions with a pH of 6.2 and 7.2 (similar to Microdacyn® and Simple Science®) were made with each chelating agents chosen: citric acid / tri-sodium, sodium phosphate, and sodium EDTA.Surfactants tested were: benezethonium chloride (benz), sodium dodecyl sulfate (SDS), cocamidopropyl betaine (coca), and Tween 20®.Surfactants (as supplied) were directly added into 60 mL of Simple Science® and 60 mL of Microdacyn® to give a final concentration of 0.1% and 1% by weight for the surfactant. Each sample was then split into vials and stored under different conditions (5°C refrigerator, 21 °C in the dark, 35°C oven).Combinations of surfactants and chelating agents were tested in Salvesan® solution. Chelating agents chosen from citric acid / tri-sodium, sodium phosphate, and sodium EDTA were combined with surfactants chosen from benezethonium chloride (benz), sodium dodecyl sulfate (SDS), cocamidopropyl betaine (coca), and Tween 20® in the following amounts:(A) 0.1 % chelating agent; 0.1 % surfactant(B) 0.1 % chelating agent; 1 % surfactant(C) 1% chelating agent; 0.1 % surfactant(D) 1% chelating agent; 1 % surfactantThe initial pH of the resulting solutions was adjusted where necessary to be approximately 7 to match that of the starting Salvesan® solution (pH 7.2). Each sample was split into smaller vials and stored in a 5°C refrigerator, in a 35°C oven and at room temperature in a dark place.Results and discussions3. pH stabilityEffect of chelating agents on pHFigure 16(A) shows the results of a pH stability study for Simple Science® and Figure 16(B) shows the results of a pH stability study for Microdacyn® each with the addition of a chelating agent selected from EDTA, phosphate and citric acid as a function of time and temperature. All the samples with additions of chelator were compared to a control sample containing only Simple Science® or Microdacyn®.The pH of Simple Science® is stable with time according to the control sample, where “stable” is as defined hereinabove, namely that the pH of the composition may not change by more than ±2 pH, preferably ±1 pH, when the composition is stored for a given period of time. Phosphate chelators appeared advantageous due to their ability to keep the pH close to the control sample and due to the maintenance of pH stability with time and temperature. EDTA in an amount of 0.1 % appeared to be similarly advantageous. A shift of pH with 1% EDTA was observed. Finally, the pH of Simple Science® combined with 0.1 % and 1 % citrate was stable with time and temperature.Phosphate chelating agent with Microdacyn® kept the pH of the resulting solution stable under every condition of storage. Additionally, although the addition of EDTA lowered the initial pH of Microdacyn®, this pH change was still in an acceptable range for wound care.Figure 17 summarises the pH variation under every storage temperature after three weeks storage. Simple Science® and Microdacyn® appeared to behave somewhat differently after the addition of chelators. Firstly, the Microdacyn® product after addition of chelator appearedto be more stable than Simple Science® with temperature. Microdacyn®, when combined with 0.1% and 1% EDTA had a greater decrease in pH compared to when phosphate chelators were used. In the case of Simple Science®, good stability with temperature was seen for all chelators. Phosphate tends to decrease pH, as does 0.1 % EDTA, whereas citrate and 1 % EDTA increased the pH.Phosphate and 0.1% EDTA appeared to be particularly advantageous chelators as they maintained an acceptable pH with respect to time and temperature.Effect of surfactants on pHFigures 18 and 19 show the effect of surfactants selected from benezethonium chloride (benz), sodium dodecyl sulfate (SDS), cocamidopropyl betaine (coca), and Tween 20® on pH with time / temperature for Simple Science® and Microdacyn® formulations respectively. Figure 20 shows the results at week 3.The Simple Science® control sample had a stable pH with time / temperature.With the addition of surfactant, greatest stability was observed at 5°C, which was close to the stability of the control sample. At higher temperatures such as the 35°C samples, larger decreases in pH were observed. 0.1 % and 1 % SDS samples as well as the 0.1% coca sample were stable with temperature / time and were similar to the control sample.The Microdacyn® control sample appeared to have stable pH with time and each temperature in reference to the control results. The 5°C samples exhibited the greatest stability and with the pH generally close to that of the control.The room temperature (20.7°C) and 35°C samples exhibited the same pH evolution as for the corresponding samples with Simple Science®, which tended to decrease when compared to the control and 5°C samples. Particularly advantageous surfactants appeared to be benzethonium chloride, SDS, and 0.1% coca.The pH results indicate changes in HOCI concentration and / or speciation are greatest at high temperature. Thus, in various embodiments, the compositions described herein are stored at temperatures less than about 20°C, preferably less than about 10°C, more preferably less than about 5°C.Combinations of chelating agent and surfactantCombinations of the chelators and surfactants mentioned above were made with the Salvesan® solution (pH 7.14).The pH of formulations containing chelator and surfactant combinations added into the Salvesan® solution were compared to a control sample containing only Salvesan® with 0.1 % or 1% chelators (Figure 21). A colour change was observed for each combination of chelating agent with benzethonium chloride.The results suggest that combinations of 0.1 % phosphate with 0.1 % and 1 % of each surfactant are advantageous due to there being only a slight variation in pH after 3 weeks storage and no effect with storage temperature. Combinations of 1% EDTA with 0.1 % surfactants could also be advantageous for similar reasons. Combinations of 0.1% EDTA or 0.1% phosphate with surfactants showed some variation, but this was not significant (maximum variation of 0.6). 1 % EDTA combined with 1% surfactant gave the largest change in pH when compared to the control, however the pH was still in an acceptable pH range for wound care.Although all combinations were acceptable, the combinations with phosphate appear to be particularly advantageous because the pH remained stable and closest to the original pH of Salvesan® (pH 7.2).4. SpectrophotometryAs detailed above, the absorbance of the DPD complex at Amax= 556 nm is assumed to be an estimate of all free chlorine species.4.1 Effect of chelating agentsTable 9: Palin Test absorbance values (% relative to Microdacyn® control) for Microdacyn® with chelating agentsTable 10: Palin Test absorbance values (% relative to Simple Science® control) for Simple Science® with chelating agentsThe absorbance of the Microdacyn® control was lower than the Simple Science® control. This is due to Microdacyn® having a lower initial concentration of free chlorine (80 ppm) than Simple Science® (112 ppm). Compared to the Simple Science® control, phosphate appears to keep the absorbance stable with a maximum loss in absorbance of about 15% suggesting the free chlorine concentration is still high. In the case of Microdacyn®, the maximum loss in absorbance is about 20%, but the absorbance is still acceptable.4.2 Effect of surfactantsTable 11: Palin Test absorbance values (% relative to Microdacyn® control) for Microdacyn® with surfactantsTable 12: Palin Test absorbance values (% relative to Simple Science® control) for Simple Science® with surfactantsWith SDS, the decrease in total chlorine was greater, with this being more pronounced at high temperatures and higher concentrations of SDS. 4.3 Effect of chelating agent and surfactantCombinations of chelating agent and surfactant were tested with Salvesan® solutions in the same manner as above. The control was Salvesan® solution with 1% phosphate and no surfactant.High absorbance values with phosphate suggest that free chlorine is still present in the Salvesan® solution after the addition of surfactant. The decrease in absorbance associated with the addition of SDS is comparable to that observed with Microdacyn® and Simple Science® in the absence of phosphate. The combination of 1% phosphate and 0.1 % SDS maintained the absorbance at the highest value relative to the control.Conclusion0.1% and 1% phosphate in combination with 0.1 % EDTA were particularly good at maintaining pH with time and temperature within an acceptable range for wound care. These combinations also gave optimal results when combined with surfactants. The most stable pH results obtained for surfactants when used with Microdacyn® and Simple Science® solutions were: SDS (0.1 % and 1 %) with both products, Benz 0.1% with Microdacyn®, and Coca 0.1 % with Simple Science®.Absorbance values did not significantly change with temperature so free chlorine concentration is believed to be stable. Some changes in absorbance were observed for SDS.These results suggest that phosphate and anionic surfactants may be particularly advantageous when used with hypochlorous acid in wound cleansing compositions.NUMBERED CLAUSES - PART 11. A wound cleansing composition comprising:(i) an anionic surfactant in an amount of from about 0.1 to about 10% by weight based on the total weight of the composition;(ii) a chelating agent in an amount of from about 0.1 to about 5% by weight based on the total weight of the composition; and(iii) a solvent; wherein the anionic surfactant is selected from the group consisting of a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof; and wherein the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof.2. The wound cleansing composition of clause 1 , wherein the wound cleansing composition is a liquid wound cleansing composition.3. The wound cleansing composition of clause 1 or 2, wherein the solvent is an aqueous solvent.4. The wound cleansing composition of any preceding clause, wherein the anionic surfactant is present in an amount of from about 0.5 to about 2% by weight based on the total weight of the composition and the chelating agent is present in an amount of from about 0.1 to about 2% by weight based on the total weight of the composition.5. The wound cleansing composition of any preceding clause wherein the chelating agent is selected from the group consisting of trisodium citrate, disodium phosphate, disodium oxalate, tetrasodium ethylenediaminetetraacetate, and mixtures thereof.6. The wound cleansing composition of any preceding clause wherein the anionic surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, sodium cocoamphoacetate, and mixtures thereof.7. The wound cleansing composition of any preceding clause wherein the pH of the composition is from about 5 to about 9, preferably from about 5 to about 8.8. A wound cleansing composition according to any preceding clause for use in treating a wound.9. The wound cleansing composition for use according to clause 8 wherein the wound comprises a microbial infection, preferably wherein the microbial infection is a bacterial infection.10. The wound cleansing composition for use according to any of clauses 8 to 9 wherein the wound comprises one or more biofilms and treating the wound comprises disrupting said one or more biofilms.11. The wound cleansing composition for use according to any of clauses 8 to 10 wherein the wound cleansing composition is non-antimicrobial.12. The wound cleansing composition for use according to any of clauses 8 to 11 wherein the non-antimicrobial cleansing composition causes less than about a 3-log reduction in the number of microbial cells in the wound when contacted with the wound for about 10 minutes.13. A method for cleaning a wound, wherein said method comprises contacting said wound with the wound cleansing composition according to any of clauses 1 to 7.14. The method of clause 13 wherein the wound comprises a microbial infection, preferably a bacterial infection.15. The method of clause 13 or 14 wherein the wound is contacted with the wound cleansing composition for less than 10 minutes, preferably for less than 5 minutes.NUMBERED CLAUSES - PART 21. An wound cleansing composition comprising:(i) an anionic surfactant in an amount of from about 0.1 to about 10% by weight based on the total weight of the composition;(ii) a chelating agent in an amount of from about 0.1 to about 5% by weight based on the total weight of the composition;(iii) an antimicrobial agent; and(iv) a solvent;(v) wherein the anionic surfactant is selected from the group consisting of a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt and mixtures thereof; and(vi) wherein the chelating agent is selected from the group consisting of a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate, and mixtures thereof.2. The wound cleansing composition of clause 1, wherein the antimicrobial agent is selected from hypochlorous acid and polyhexamethylene biguanide, preferable wherein the antimicrobial agent is hypochlorous acid.3. The wound cleansing composition of clause 1 or clause 2, wherein the antimicrobial wound cleansing composition is a liquid wound cleansing composition.4. The wound cleansing composition of any of clauses 1 to 3, wherein the solvent is an aqueous solvent.5. The wound cleansing composition of any of clauses 1 to 4, wherein the anionic surfactant is present in an amount of from about 0.5 to about 2% by weight based on the totalweight of the composition and the chelating agent is present in an amount of from about 0.1 to about 2% by weight based on the total weight of the composition. The wound cleansing composition of any of clauses 1 to 5, wherein the chelating agent is selected from the group consisting of trisodium citrate, disodium phosphate, disodium oxalate, and tetrasodium ethylenediaminetetraacetate. The wound cleansing composition of any of clauses 1 to 6, wherein the chelating agent is a mixture of a phosphate salt and an ethylenediaminetetraacetate salt, preferably a mixture of disodium phosphate and tetrasodium ethylenediaminetetraacetate. The wound cleansing composition of any of clauses 1 to 7, wherein the anionic surfactant is selected from the group consisting of sodium lauroyl sarcosinate, sodium cocyl glutamate, and sodium cocoamphoacetate. The wound cleansing composition of any of clauses 1 to 8, wherein the pH of the composition is from about 5 to about 9, preferably from about 5 to about 8. A wound cleansing composition according to any of clauses 1 to 9 for use in treating a wound. The wound cleansing composition for use according to clause 10 wherein the wound comprises a microbial infection, preferably wherein the microbial infection is a bacterial infection. The wound cleansing composition for use according to clause 10 or 11 wherein the wound comprises one or more biofilms and treating the wound comprises disrupting said one or more biofilms. The wound cleansing composition for use according to any of clauses 10 to 12, wherein the cleansing composition causes at least about a 3-log reduction in the number of microbial cells in the wound when contacted with the wound for about 10 minutes. A method for cleaning a wound, wherein said method comprises contacting said wound with the wound cleansing composition according to any of clauses 1 to 9. The method of clause 14 wherein the wound comprises a microbial infection, preferably a bacterial infection. The method of clause 14 or clause 15 wherein the wound is contacted with the wound cleansing composition for less than 10 minutes, preferably for less than 5 minutes.

Claims

CLAIMS1. A wound cleansing composition comprising:(i) a surfactant in an amount of from about 0.1 to about 20% by weight of the composition;(ii) a chelating agent in an amount of from about 0.5 to about 10% by weight of the composition; and(iii) an aqueous solvent in an amount of at least about 50% by weight of the composition; wherein the composition does not include sodium oleate or a cationic surfactant; wherein the surfactant is selected from anionic surfactants, amphoteric surfactants, and mixtures thereof; and wherein the chelating agent is selected from a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof.

2. The wound cleansing composition of claim 1 , wherein the weight ratio of chelating agent to surfactant is about 5:1 to about 1 :5, preferably about 4:1 to about 1 :1.

3. The wound cleansing composition of claim 1 or claim 2, wherein the anionic surfactant is selected from a glutamate salt, a sarcosinate salt and an isethionate salt, preferably a fatty acid glutamate salt or a fatty acid sarcosinate salt, wherein the fatty acid comprises 8 to 24 carbon atoms, more preferably wherein the anionic surfactant is selected from a lauroyl sarcosinate salt and a cocyl glutamate salt.

4. The wound cleansing composition of any of claims 1 to 3, wherein the amphoteric surfactant is selected from a hydrocarbyl-amphoacetate salt, a hydrocarbyl- amphodiacetate salt, and mixtures thereof, wherein the hydrocarbyl groups comprise 8 to 24 carbon atoms.

5. The wound cleansing composition of any of claims 1 to 4, wherein the surfactant is selected from sarcosinate salts, glutamate salts, amphoacetate salts, and mixtures thereof, preferably selected from a lauroyl sarcosinate salt, a cocyl glutamate salt, a cocoamphoacetate salt, and mixtures thereof.

6. The wound cleansing composition of any preceding claim, wherein the surfactant is present in an amount of from about 0.5 to about 10% by weight of the composition.

7. The wound cleansing composition of claim 6, wherein the surfactant is present in an amount of from about 1 to about 5% by weight of the composition.

8. The wound cleansing composition of any preceding claim, wherein the chelating agent is present in an amount of from about 0.5 to about 5% by weight of the composition.

9. The wound cleansing composition of claim 8, wherein the chelating agent is present in an amount of from about 1 to about 2% by weight of the composition.

10. The wound cleansing composition of any preceding claim, wherein the chelating agent is selected from sodium or potassium salts of citrate, phosphate, oxalate, ethylenediaminetetraacetate, and mixtures thereof.

11. The wound cleansing composition of any preceding claim, wherein the surfactant is an anionic surfactant.

12. The wound cleansing composition of any preceding claim, wherein the chelating agent is selected from a citrate salt, an oxalate salt, an ethylenediaminetetracetate salt and mixtures thereof, preferably wherein the chelating agent is an ethylenediaminetetraacetate salt.

13. The wound cleansing composition of any preceding claim, wherein the pH of the composition is from about 5 to about 9, preferably from about 6 to about 8.

14. The wound cleansing composition of any preceding claim, wherein the composition is free of antimicrobial agents, preferably wherein the composition causes less than about a 3-log reduction in the number of microbial cells in the wound when contacted with the wound for up to about 10 minutes.

15. A method for cleansing and / or irrigating a wound, wherein said method comprises contacting said wound with a wound cleansing composition, wherein the wound cleansing composition comprises:(i) a surfactant in an amount of from about 0.1 to about 20% by weight of the composition;(ii) a chelating agent in an amount of from about 0.1 to about 10% by weight of the composition; and(iii) an aqueous solvent present in an amount of at least about 50% by weight of the composition; wherein the surfactant is an anionic surfactant, an amphoteric surfactant, or a mixture thereof, and wherein the chelating agent is selected from a citrate salt, a phosphate salt, an oxalate salt, an ethylenediaminetetraacetate salt, and mixtures thereof, preferably wherein the wound cleansing composition is defined according to any of claims 1 to 14.

16. The method of claim 15, wherein the wound is contacted with the wound cleansing composition for less than about 15 minutes, preferably less than about 10 minutes.

17. The method of any of claims 15 or 16, wherein the wound comprises one or more biofilms and the one or more biofilms are disrupted by the wound cleansing composition.

18. An aqueous wound cleansing composition comprising:(i) a surfactant in an amount of about 0.01 to about 5% by weight of the composition;(ii) a chelating agent in an amount of about 0.01 to about 5% by weight of the composition; and(iii) hypochlorous acid; wherein the surfactant is selected from sarcosinates, glutamates, isethionates, amphoacetates, amphodiacetates, betaines, amidoalkylbetaines, polysorbates, sulfates and mixtures thereof; wherein the chelating agent is selected from citrates, oxalates, phosphates, ethylenediaminetetraacetates, and mixtures thereof; provided that when the surfactant includes a betaine or an amidoalkylbetaine surfactant, the chelating agent is not an ethylenediaminetetracetate; wherein the composition has a pH of from about 4 to about 8, and does not include a cationic surfactant.

19. The wound cleansing composition of claim 18, wherein the weight ratio of chelating agent to surfactant is about 10:1 to about 1 :10.

20. The wound cleansing composition of claim 18 or claim 19, wherein the chelating agent is an ethylenediaminetetraacetate and present in an amount of no greater thanabout 1 % by weight of the composition, preferably in an amount of no greater than about 0.5% by weight of the composition.21 . The wound cleansing composition of any preceding claim 18 to 20, wherein the surfactant is selected from glutamates, sarcosinates, isethionates and sulfates, preferably wherein the surfactant is selected from glutamates and sarcosinates, more preferably wherein the surfactant is a fatty acid glutamate or a fatty acid sarcosinate, wherein the fatty acid comprises 8 to 24 carbon atoms; or wherein the surfactant is selected from a hydrocarbyl-amphoacetate, a hydrocarbyl-amphodiacetate, a hydrocarbyl betaine, a hydrocarbyl-amidoalkylbetaine and mixtures thereof, wherein the hydrocarbyl groups comprise 8 to 24 carbon atoms, preferably wherein the surfactant is selected from a fatty acid amphoacetate or fatty acid amidoalkylbetaine wherein the fatty acid comprises 8 to 24 carbon atoms; or wherein the surfactant is a polysorbate.

22. The wound cleansing composition of any preceding claim 18 to 21 , wherein the surfactant is selected from sarcosinates, glutamates, amphoacetates and mixtures thereof, preferably wherein the surfactant is selected from a lauroyl sarcosinate, a cocyl glutamate, a cocoamphoacetate, and mixtures thereof.

23. The wound cleansing composition of any preceding claim 18 to 22, wherein the surfactant is present in an amount of from about 0.01 to about 1 % by weight of the composition, preferably wherein the surfactant is present in an amount of from about 0.1 to about 1 % by weight of the composition.

24. The wound cleansing composition of any preceding claim 18 to 23, wherein the chelating agent is present in an amount of from about 0.01 to about 1 % by weight of the composition.

25. The wound cleansing composition of any preceding claim 18 to 24, wherein the chelating agent includes a phosphate present in an amount of about 0.01% to about 1% by weight, and / or wherein the chelating agent includes an ethylenediaminetetraacetate salt present in an amount of about 0.01% to about 0.5% by weight of the composition.

26. The wound cleansing composition of any preceding claim 18 to 25, wherein the pH of the composition is from about 5 to about 7, preferably from about 6 to about 7.

27. The wound cleansing composition of any preceding claim 18 to 26, wherein the composition causes at least about a 3-log reduction in the number of microbial cells in a wound when contacted with the wound for up to about 10 minutes.

28. A method for treating a wound by contacting the wound with an aqueous wound cleansing composition and disrupting one or more biofilms of the wound, wherein the composition is aqueous and comprises:(i) a surfactant in an amount of about 0.01 to about 10% by weight of the composition;(ii) a chelating agent in an amount of about 0.01 to about 10% by weight of the composition; and(iii) hypochlorous acid; wherein the surfactant is selected from anionic surfactants, non-ionic surfactants, amphoteric surfactants, and mixtures thereof; wherein the chelating agent is selected from citrates, oxalates, phosphates, ethylenediaminetetraacetates, and mixtures thereof; and wherein the composition has a pH of from about 4 to about 8, and does not include a cationic surfactant, preferably wherein the composition is defined according to any of claims 18 to 27.

29. The method of claim 18, wherein the method comprises cleansing the wound by contacting the wound with the wound cleansing composition for up to about 10 minutes or irrigating the wound with the wound cleansing composition.

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