GB2442519A

GB2442519A - Wound treatment compositions

Info

Publication number: GB2442519A
Application number: GB0619375A
Authority: GB
Inventors: Abraham Venter; Nicholas Meakin
Original assignee: Forum Bioscience Holdings Ltd
Current assignee: Forum Bioscience Holdings Ltd
Priority date: 2006-10-02
Filing date: 2006-10-02
Publication date: 2008-04-09
Also published as: EP2068892A1; GB0619375D0; WO2008041031A1

Abstract

A composition comprising an anolyte of electrochemically activated water for treating a wound; the composition having a chlorine content of no more than 50ppm. The composition may be used to treat or prevent a wound infection, particularly a bacterial wound infection caused by Methicillin-resistant Staphylococcus aureus or Vancomycin-resistant Enterococcus spp. The composition may also comprise: a catholyte of electrochemically activated water; 10-20mg/l active oxygen species; 10ppm chlorine dioxide; no more than 10ppm hypochlorite; a redox potential of at least +900mV; one or more therapeutically active agents; and have a pH between 6 and 8. A composition comprising an electrochemically activated water anolyte, having a chlorine content of no more than 50ppm, for cleaning uncompromised skin is further claimed. One use of such compositions in the manufacture of a medicament and a wound dressing is also claimed.

Description

Wound Healing Compositions The present invention rclates to improved

wound healing compositions for cleaning and irrigating wounds, treating and preventing wound infections and accelerating the rate at which wounds heal.

As used herein, the term "wound" includes surgical Incisions as well as wounds caused by accidental trauma or disease, burns, abrasions and minor irritations of the skin.

Wound healing is a complex process involving a highly regulated cascade of biochemical and cellular events with the object of restoring tissue integrity following injury. The repair process in human tissue combines aspects of Ussue repair and regeneration in response to tissue damage or loss. Wound healing is a concert of simultaneously occurring processes rather than a series of discrete steps, which, for convenience, can be characterised as haemostasis, inflammation, proliferation and remodeling.

Early wound healing events include coagulation and inflammation. Fibrin is the end product of the coagulation pathway and, besides inducing haemostasis, is also the primary component of the tissue matrix seen in the early phases of wound healing.

It provides a framework for the migration of inflammatory and mesenchymal cells.

Monocytes transform into macrophages as they migrate from capillaries into extra vascular space. Macrophages phagocytose bacteria and tissue debris and secrete enzymes (collagenase and elastase) that break down damaged matrix. They also secrete cytokines, prostaglandins, oxygen free radicals and other regulators of Intermediate wound healing events include mesenchymal cell migration and proliferation, angiogenesis and epithelialisation. Fibroblasts from adjacent undamaged tissue migrate into the wound matrix under the influence of cytokines and secrete collagen and proteoglycans of connective tissue matrix. Angiogenesis is the process by which blood flow across a wound is re-established. Capillaries sprout from existing venules on each side of the wound and connect with each other. In unclosed wounds, however, the new capillaries fuse only with neighbours migrating in the same direction and form granulation tissue. Epithelialisation begins within hours of injury and results in the resurfacing of any denuded area by cell migration and proliferation, creating a multi-layered epithelium.

Late wound healing events include collagen synthesis by fibroblasts, which have migrated Into the wound. Collagen provides structural configuration, strength and a matrix for cellular movement in the wound.

There are many potential causes of disruption in the healing process which may lead to a prolonging of the inflammatory phase and the generation of a cascade of tissue responses that prevents healing and leads to the formation of a chronic wound. A major risk, especially with open wounds, is the development of infection, particularly bacterial infection. Wounds that remain infected cannot proceed to the granulation tissue phase of wound healing.

A particular hazard, especially for hospitalised patients, is the infection of a wound by an antibiotic-resistant bacterial strain. Two of the most common are Methicillin-resistant Stap/yIococcus aureu.c (MRSA) and Vancomycin-resistant Enicrococcus spp.

(V RE). An individual can become a carrier of MRSA in the same way that they can become a carrier of ordinary Stap4y/ococcus aureus, namely by physical contact with the organism. Most commonly, the organism is transmitted by physical contact with someone who is either infected with the organism or carries it on his or her skin. If the organism is in the nose or is associated with the lungs rather than the skin then it may be passed around by droplet spread from the mouth and nose. One of the most important precautions to prevent spread of MRSA from a person infected with it is that they are placed in contact isolation. This type of isolation requires everyone in contact with the patient to be very careful about hand washing after touching either the patient or anything in contact with the patient. If the organism is in the nose or lungs it may also be necessary to have the patient in a room to prevent spread to others by droplet spread. Because dust and surfaces can become contaminated with the organism, the cleaning of surfaces is also important.

Repeated trauma, foreign bodies, pressure necrosis, ischaemia and tissue hypoxia due to a poor blood supply are just some of the other factors which may promote a chronic inflammatory state in a wound. Some examples of wounds which may be slow-or non-healing are diabetic ulcers, pressure sores, ulcerated wounds, venous stasis ulcers and burns.

According to the National Institutes of Health, chronic wounds such as venous leg ulcers, pressure sores, ischaemic ulcers and diabetic foot ulcers, affect more than 4 million Americans each year and cost about $9 billion to treat.

Conventionally, disinfectants and other chemotherapeutic agents are topically applied to wounds in order to restore the normal healing process and prevent infection. Many conventional disinfectants are toxic, flammable and irritating to the skin, eyes and throat and so must be used with extreme caution. Cleaning the wound with a conventional disinfectant may be effective to kill bacteria but it may also create a layer of superficial necrosis that can delay wound healing.

Additionally, many known dismfectants such as chlorhexidine, providine-iodine, alcohol, hydrogen peroxide (in higher concentrations, as it is normally used) are toxic to fibroblasts and epithehal cells and so are likely to delay or prevent the healing of open wounds and ulcers.

McCauley et a! (Differential in vitro Toxicity of Topical Antimicrobial Agents to Human Keratinocytes. J Surg Res, 1992; 52:276-285) have shown that both silver sulfadiazine and Sulfamylon , which are used in the treatment of skin graft donor sites, wounds, burns, leg ulcers and pressure sores are toxic to fibroblasts in tissue culture at concentrations of 0.0O5% and 0.1%, respectively. Leitch et al (Inhibition of Wound Contraction by Topical Antimicrobials. Aust. New Zealand J Surg, 1993 Apr; 63(4):289-93) have presented data showing that silver sulfadiazine, Sulfamylon and silver sulfadiazine with chlorohexadine significantly retarded wound healing in the acute wound model.

Furthermore, many of the disinfectants conventionally used to clean and irrigate wounds are harmful to the environment and their use should therefore be kept to a minimum. Many of the commonly used dismfectants have an extremely high chemical load and therefore are potentially very harmful to the environment. The chlorine content of disinfectants in particular has come under scrutiny in Europe.

In the light of the foregoing, it is clear that whilst the application of topical chemotherapeutic agents is essential in the prevention and treatment of infection and enhancement of wound healing, there is a need for an agent which effectively prevents or treats infection of the wound but does not retard and possibly even accelerates the healing process.

Electrochemically activated water (also sometimes referred to as hydroactive water) is water which has undergone electrochemical activation (ECA). Such treatment involves the exposure of water and the natural salts therein or salts added to it, to a substantial electrical potential difference.

If an anode (+) and a cathode (-) are placed in pure water and a direct current is applied, electrolysis of the water will occur at the poles leading to a breakdown of the water into its constituent elements, producing gaseous hydrogen and oxygen.

However, if sodium chloride is added to the water to form a solution, the dominant electrolysis end product is chlorine, hypochiorite or hypochiorous acid (HOd), a chlorine-based reagent which may be used to kill micro-organisms.

The electrochemical activation process is improved by interposing an ion-permeable membrane between the positive and negative electrodes, forming an anode chamber and a cathode chamber. Preferably, the aqueous sodium chloride solution is fed into both the anode chamber and the cathode chamber and the sodium chloride, which is in its ionised form in solution (Nat and Cl), is exposed to the controlled electrical potential difference between thc cathode and the anode. This potential difference causes the Na ions to migrate to the cathode and the CI ions to migrate to the anode. The membrane which separates the anode chamber and the cathode chamber allows ions to pass unimpeded, whilst the un-ionised water and any organic molecules in the water are unable to pass through the membrane.

The presence of an ion-permeable non -ceramic membrane in the electrolysis apparatus allows the necessary ions to be concentrated in the anode and cathode chambers, which results in the formation of metastable ions with high biocidal activity and very low chlorine levels. Although a similar process takes place in conventional electrochemical activation processes, the presence of anion-permeable membrane prevents the complex reactive species formed at the cathode and anode from reacting with one another and being neutralised. The specific choice of a non-ceramic membrane further refines the chemical processes.

As the electrical potential is applied, high concentrations of Cl-and OH-build up on the anode side of the membrane and Na and H build up on the cathode side of the membrane. The unstable chemical state results in complex reactions which produce a metastable solution containing a wide variety of very reactive ions and molecules, such as those set out in Table 1.

Table I

____________________ Reactive Molecules Reactive Ions Anolyte 03 _________________ 02 ____________ H202 0H Cl02 ClO

______________ HCIO

________________ C'2 _______________ _____________ ____ HC1 HCJO3 _____________ Catholyte H202 H3O + I NaOH Na L H2 _____ It is the formation of these complex chemical species which leads to the formation of solutions described as electrochemically activated water or hydroactive water.

Some of the reactive constituents formed during the electrochemical activation of the sodium chloride solution include hypochiorite (HCIO), hydrogen peroxide (H202), ozone (Os), chlorine (Cl2) and chioric acid (HC1O). Most of these compounds are formed in the anode chamber. They are acidic, giving the anolyte a pH of between 2.4 and 4 and oxidising activity. In the cathode chamber, the reactive species are basic and are reducing agents. The catholyte will have a pH of between 10 and 12.

The anolyte and catholyte produced by the electrochemical activation of an aqueous sodium chloride solution also exhibit opposing potentials, the anolyte having a redox potential of approximately + I O5OmV, while the catholyte has a redox potential of approximately -850mV. This is compared to the redox potential of the starting material of approximately +300 to 400mV.

In the apparatus with an ion-permeable membrane, two distinct solutions are formed, the catholyte and the anolyte, and these solutions can be separately extracted or they can be mixed.

The anolyte solution exhibits mild oxidative power and can destroy micro-organisms, and therefore has useful sterilizing and disinfectant properties. The catholyte solution has properties which make it useful as a detergent and as a surfactant. Its reducing power also means that the catholyte is effective in precipitating metal ions out of water and it can be used to soften hard water.

Whilst the oxidative and reductive properties of the anolytes and catholytes of electrochemically activated water have previously been recognised, it has now unexpectedly been found that compositions comprising the anolyte of electrochemically activated water may be used to treat and prevent wound infection and to promote wound healing. What is more, the use of such anolyte solutions in this manner is safe. Whilst the anolyte solutions are capable of killing a broad spectrum of micro-organisms, including MRSA, the solutions are benign in terms of fumes, corrosion and their effect on the skins of humans and animals.

In the past, it was generally believed that the disinfectant activity of electrochemically activated water is a function of the hypochlorite concentration of the water. As the concentration of hypochiorite increases, so does the redox potential (ORP) and the disinfectant activity of the electrochemically activated water. As a result, it was generally considered that the greater the hypochiorite content of the electrochemically activated water, the greater its disinfectant activity.

Indeed, it was generally thought that the electrochemically activated water must include at least 50 to 200ppm hypochlorite in order for it to exhibit acceptable disinfectant activity. Where electrochemically activated water has been used in the past as a disinfectant, the hypochloritc or chlorine concentration has been greater than 5Oppm and is usually much greater, sometimes as high as 65Oppm.

International Publication No. WO 01/13926 (Sterilox Medical (Europe) Ltd) relates to "super-oxidised" water based on hypochiorous acid, such as that obtained by electrochemical activation of saline solution, for treating open wounds such as leg ulcers. Although the disclosure includes very little technical information about the make-up of the super-oxidised water, its activity is said to be due to the hypochlorous acid. International Publication No. WO 2003/028741 (Aquilabs S.A.) relates to compositions comprising hypochlorous acid for use in prophylactic and therapeutic medical applications. The hypochlorous acid is said to be the bactericidal agent and the claimed compositions comprise 6.5 to 7.3% hypochiorous acid. Compositions with a hypochlorous acid concentration of 5000ppm were used in one study described in the application.

Therefore, it was previously believed that electrochemically activated water having a chlorine content of 5Oppm or less would not exhibit any disinfectant activity and would not be effective against micro-organisms and certainly not effective against antibiotic resistant bacterial strains. However, it has now been discovered that electrochemically activated water with a chlorine content of no more than 5Oppm does exhibit disinfectant activity. Indeed, electrochemically activated water with a chlorine content as low as 8ppm or less has been shown to exhibit disinfectant activity.

The disinfectant activity of this low chlorine electrochemically activated water is not a result of the hypochiorite in the water, but rather it appears to be due to the presence of activated chlorine and oxygen species. This activity is thought to be masked" in conventional electrochen-ncally activated water by the high levels of chlorine and the activity of the hypochlorite. However, it has now been found that the activated chlorine and oxygen species produce a redox potential high enough for the water to have disinfectant activity (greater than +900mV), whilst having a low chlorine content. Indeed, it has been found that electrochemically activated water with a chlorine content of less than 5Oppm, or even of no more than 8ppm has disinfectant activity and can be used in the present invention to kill or destroy a broad spectrum of bacterial species including MRSA. This chlorite content is extremely low compared to the hypochlorous acid concentrations disclosed as being necessary in prior art such as WO 2003/028741, as discussed above.

Therefore, according to a first aspect of the present invention, a composition comprising an anolyte of electrochemically activated water is provided, for use in treating a wound, the composition having a chlorine content of no more than about 5Oppm.

Herein, the treatment of a wound means encouraging wound healing and preferably includes reducing and/or preventing infection of the wound and the surrounding areas.

In a particularly preferred embodiment, the composition is also for use in promoting wound healing. The promotion of wound healing refers to accelerating wound healing, the wound taking less time to heal than would have been required without the application of the compositions according to the present invention.

In one embodiment of the invention, the composition comprises a combination of the anolyte and the catholyte of electrochemically activated water. In a particular embodiment, the catholyte is added to the anolyte in order to adjust the pH of the composition to a desired value, namely between 4 and 8, preferably between 6 and 8 and more preferably approximately 7. Alternatively, the pH of the compositions according to the present invention is adjusted to the aforementioned values by other means, for example by adding a buffer.

The compositions of the present invention have the advantage that their pH may be adjusted without the loss of disinfectant and biocidal activity. Combinations of the anolyte and the catholyte of clectrochemically activated water retain the disinfectant and biocidal activity of the anolyte.

In preferred embodiments of the present invention, the pH of the composition remains constant, with variations of 0.5 of a unit or less, and preferably of 0.1 of a unit or less. Compositions which have a stable pH value between 6 and 8 are particularly useful in the present invention, as they are advantageous for use in physiological systems, as proposed herein.

In another embodiment of the present invention, the compositions have a chlorine content of no more than about 35ppm or no more than about 8ppm. The chlorine content may be from about 0.3 to about SOppm, preferably from about I to about 35ppm, and more preferably from about 5 to about 2Oppm. It is desirable to have electrochemically activated water with a minimal chlorine content for a number of reasons. The water is so benign that, at effective doses, it is safe for use on humans and animals, even on open wounds. The low chlorine content of the compositions is important for promoting wound healing.

The compositions according to the prescnt Invention preferably have a redox potential of at least about +900mV, and preferably of at least about + I 000mV or at least about +lO5OmV.

Preferably, the compositions used in the present invention include active chlorine and oxygen species and the concentration of the active oxygen is preferably between about 10 and about 2Omg/l, preferably between about 13 and about 20 mg/I or between about 11 and about 1 7mg/l.

-10 -In a preferred embodiment, the level of chlorine dioxide (dO2) present in the compositions is less than about lOppm, preferably less than about 5ppm, and most preferably less than about lppm. For example, the level of chlorine dioxide is no more than about 9, 8, 7, 6, 5, 4, 3, 2 or lppm.

In a further preferred embodiment, the level of hypochiorite in the compositions is less than about lOppm, preferably less than about Sppm, most preferably less than about lppm. For example, the level of hypochiorite is no more than about 9, 8, 7, 6, 5, 4, 3, 2 or lppm.

The electrochemically activated water used in the present invention can be produced in a number of ways, including those well known in the art.

Conventional electrolysis processes operate at voltages and/or power densities at which HC1O and/or C102 are produced. Indeed, it is these species in conventional electrochemically activated water which is traditionally relied upon for the biocidal activity.

However, as discussed above, electrochemically activated water with a minimal chlorine and hypochlorite content is to be used in the present invention. The chlorine and hypochiorite content of the electrochemically activated water is affected by the amount of sodium chloride in the water prior to the electrochemical activation process, the current used to electrolyse the solution (the size of the current and the length of time the water is exposed to it) and thc rate of flow of the salt solution through the different chambers of the electrolytic cell.

Compositions for use in the present invention may be produced by running the electrolysis process at a voltage and/or power density which is higher than that at which 02 and Cl2 are produced, but which is also lower than that at which HCIO and C102 are produced. Preferably, the voltage adjacent to the electrode face is between 1.35 and 1.63V, more preferably between 1.4 and 1.5V and most preferably between 1.42 and 1.47V. It is important to note that these values do not refer to -11 -the voltage across the whole system. The chemical reactions are taking place at the face of the electrodes and so it is the voltage here that is significant.

A person skilled in the technical field of the present invention would have no difficulty adjusting the parameters of the electrolysis process in order to achieve the voltage and/or power density at the electrodes required to produce the low chlorine and low hypochiorite water used in the compositions of the present invention, once he is aware of the required voltage and/or power density at the electrodes relevant to the membrane in use.

The ratio of the anolyte:catholyte flow can be from 5:95 to 95:5 with the optimum flow ratio being 60:40, whilst the current should be between I and 20 amps with the preferred range being 6 to 12 amps.

The variation of the chlorine concentration in ppm with water flow at constant current is shown in Table 2.

Table 2

Total Flow Anolyte _________ Catholyte litres/hr Flow CI (ppm) ORP pH Flow pH ___________ _______ __________ __________ _________ 1/hr __________ 37.2 37.2 0 n/a 6.78 0 n/a 37.2 31.2 200 1053 3.16 6 12.28 39 27.6 250 1060 3.05 11.4 12.19 42 24 250 1069 2.87 18 11.98 42 22.8 300 1072 2.7 19.8 11.82 42 16.2 375 11093 2.45 25.8 11.89 In addition, the application of a low current during the electrocheniical activation process also results in a solution with a reduced chlorine and hypochlorite content.

This is likely to be due to the fact that the lower magnetic field has a lower ability to attract the negative chloride ions during the brief period that any specific chloride ion is within the electromagnetic field. As a result there is a far greater probability -12 -that the electrolysis will involve the water molecules which lie alongside the electrodes and produce oxygen based species than chlorine-based species.

Where the chlorine and hypochiorite content of the electrochemically activated water is to be limited by using a low sodium chloride concentration in the water fed into the apparatus carrying out the electrochemical activation, the water fed into the apparatus and electrochemically activated preferably has a sodium chloride concentration of between 1000 and 5000ppm, and preferably between 2000 and 3000ppm chloride ion concentration.

The conventional electrochemical activation processes apply a current of approximately 10-20 amps to the sodium chloride solution. In order to reduce the chlorine and hypochiorite content of the electrochemically activated water, it is recommended that the current be reduced to between I and 10 amps with the preferred range being between 5 and 9 amps.

Regardless of the method used to produce the electrochemically activated water with low chlorine and hypochiorite content, the water has the beneficial properties utilised by the present invention.

The low chlorine electrochemically activated water used in the present invention may be generated using the ECA 2000 Series generator equipment available from Forum Bioscience Holding, Redhill, Surrey, UK. This system significantly reduces the formation of undesirable trihalomethane and chloroamine by-products.

The main principle of the ECA 2000 machines is an electrochemical synthesis of gaseous mixture of oxidants from a dilute solution of sodium chloride under pressure in diaphragm modular electrochemical elements, each of which is a separate electrochemical rector. The block diagram of such a device is presented in Figure 1.

As shown in Figure 1, sodium chloride solution is delivered into the electrochemical reactor. The process results in a partial division of sodium chloride solution into -13 -activated chlorine and oxygen based oxidants in the anode chamber, and hydrogen and sodium hydroxide formed in the cathode chamber. The oxidants produced in the anode chamber together with micro-droplets of water arc collected (preferably in a darkened acid resistant air tight chemical drum). The electrochemically activated water is then delivered by the injection pump into the part of water to be processed resulting in a dilute solution of oxidants in the final treated water. Hydrogen is generated in the cathode chambers of electrochemical elements and is vented to air through the catholyte discharge tube.

Previous equipment used a ceramic membrane to separate the solutions resulting from close Contact with the electrodes. The ECA 2000 includes a newly developed "flat" core which consists of two half cells working at +15 to 0 volts and 0 to -15V, working back to back where the water to be processed flows across the electrodes and the electrode pairs (and thus the solutions) are separated by an ion exchange membrane. It is this core which can preferably be used to produce the electrochemically activated water which is described herein. It is non-ceramic.

The apparatus preferably has a feedback mechanism to maintain a constant current, which is dependent upon the ionic strength of the water, which is in turn dependent upon the salt content and the nature of the water used.

That the electrochemically activated water produced by the ECA 2000 series machines has an exceptionally high concentration of oxygen is shown in Figure 2.

For comparison, the normal saturated concentration for oxygen in water is approximately 8.3mg/litre. In Figure 2, "Hydroactive" is the electrochemically activated water anolyte stream from an ECA 2000 machine and "Cell Waste Stream" is the electrochemically activated water catholyte stream from an ECA 2000 machine.

Provided that the storage conditions are suitable, electrochemically activated water, and the compositions comprising an anolyte of this water according to the present invention, can be stored for periods of weeks or months. in a preferred embodiment, the compositions can be stored for more than 72 hours. Indeed, -14 -experiments show the compositions of the present invention to be stable even after storage for between 4 and 8 weeks.

As discussed above, the disinfectant activity of the minimal chlorine electrochemically activated water is due to active chlorine and oxygen species in the water. It is clear that if gas is allowed to escape from the water during its storage or use, the activity will be diminished or lost. Therefore, it is necessary to ensure that the water is stored in a closed system which will keep the loss of gas from the water to a minimum. Any stirring or other agitation of the water should also be avoided, as this will encourage gas to escape from the water.

When stored in sealed bottles with minimal head space, the dissolved active oxygen species will remain in solution at a concentration of about 10 to 20mg/I (remaining above the normal saturated concentration for oxygen in water, which is approximately S.3mg/l) for a considerable period of time, thus maintaining the activity of the product (see Figures 2 and 3).

Figure 3 is a graph showing a three-day study of dissolved oxygen concentrations vs. time for electrochemically activated water produced by an ECA 2000 machine.

The compositions of the present invention are ecologically friendly and present no problems for the environment. This is shown by the concentrations of chlorite (do2), chlorate (ClO2) and perchlorate (dO4) measured in neat, freshly prepared electrochemically activated water, as recorded in Table 3.

Table 3 -Concentrations of chlorine species found in neat electrochernically activated water as produced in ECA 2000 machine Species Concentration Chloride Cl 2600-2800 mg/kg Hypochlorite ClO 9 mg/I Chlorite C102 <0.2 mg/I Chlorate CIO 0.3-1.2 mg/i Perchlorate dO4 8-13 ng/l -15-The activity of compositions according to the present invention against bacteria, viruses and fungi species can be seen from Tables 4, 5 and 6 below.

Table 4 -Anti-microbial efficacy of electrochemically activated water with minimal chlorine content as produced by ECA 2000 generator Dilution-neutralisation method for 1 minute contact time.

Viable count (cfu/ml) for test mixture (N) at concentrations: Test organism Neat 50% v/v 5% v/v ___________________ (approx l4Oppm) (approx 7Oppm) (approx 7ppm) Pseudomonas aeniginosa <1.5 x 102 <1.5 x 102 <1.5 x 102 Staphylococcus aureus <1.5 x 102 <1.5 x 102 >3.0 x I o Salmonella (enterztzd:s) <1.5 x 102 <1.5 102 <1.5 x I 2 abonj _________________ _________________ ________________ Eschench:a cob <1.5 x 102 <1.5 x 102 <1.5 x 102 Campylobacterjejurn <1.5 x 102 <1.5 x I 2 <1.5 x I 2 Reduction in viability at test concentration: Test organism ____________________ Ncat 50% v/v 5% v/v Pseudomonas aeruginosa 2.6 x I o 2.6 x I 5 2.6 i o Staphjilococcus aureus 3.3 i 0 3.3 x I 0 1.7 x I o Salmonella (enteritidis) 3.3 x i05 3.3 x IO 3.3 x i05 abonji _________________ _________________ ________________ Escherichia coli 3.1 x I o 3.1 x i05 3.1 x I o Campylobaaerjejun: 1.3 x I o 1.3 x 1 o 1.3 x 1 o Table 5 -Electrochemically activated water produced by an ECA 2000 generator: Virucidal efficacy against Influenza A virus: Reduction in virus infectivity Sample Reduction in Infectivity (log10) / Contact time ___________________ ____________ (minutes) ____________ 1 5 10 30 Test substance Neat = 5.6 = 5.5 = 5.7 = 5.8 Test substance 3.7 4.2 4.9 = 5.8 (approx_l4ppm_Cl) __________ __________ __________ __________ Test substance 0.3 1.0 1.3 1.6 (approx_I.5ppm_Cl) __________ __________ __________ __________ Test substance (approx 0.6 ppm Cl) 0 (-0.2) 0 (-0.1) 0.4 0.4 -16 -Table 6 -Measurement of inhibition of growth of Saprolegmaparasitica by electrochemically activated water with 24 hour incubation, 1 minute contact time.

Hydroactive Colony diameter (mm) Mean concentration colony Inhibition (%) Replicate Replicate Replicate Iiameter of growth A B C (mm) _______ 0 36.30 34.55 35.25 35.37 N/A (SDW control) __________ __________ ___________ ___________ __________ 33.30 32.60 28.40 31.43 11.14 (Neat) _____ _____ _____ ______ _____ 32.95 27.80 29.40 30.05 15.04 33.35 33.45 32.30 33.03 6.62 34.25 32.15 34.70 33.70 4.72 33.50 34.40 34.35 34.08 3. 65 1 34.80 35.20 33.80 34.60 2.18 The wound healing compositions of the present invention can be used directly on the wound, either to clean or irrigate it, or in combination with a wound dressing.

Some examples of wound dressings in current use include conventional materials such as gauze, cotton, wool, lint, gamgee, sponges, and other absorbent materials, as well as low-adherent dressings, vapour permeable films/membranes, hydrogels, hydrocolloids, polysaccharide dressings, alginates, foams, de-odorisers, paste bandages, tulles, plain and medicated, desloughing agents and replaces the need to use anti-microbials. Where appropriate, the wound dressing may be soaked in a wound healing composition of the present invention. However it is used, a composition of the present invention would be expected to kill any bacteria already present in the wound and prevent any further bacteria from taking up residence in it.

It is envisaged that a fresh wound would be cleaned with a composition according to the first aspect of the present invention. Further washing could take place whenever the wound dressing is changed or at predetermined intervals. Although a wounded area may be soaked in, or even submersed in, a composition of the present invention, this manner of prolonged contact of the wound with the composition is not necessary for the desired wound treatment and promotion of wound healing.

-17 -The compositions according to the present invention are effective in treating even severely infected wounds. The treatment may, for example, involve washing the wound I to 3 times a day for a period of 2 to 5 days, or for as long as the wound takes to heal.

When using compositions having a chlorine content of approximately 5oppm, a wound will, for example, typically be washed using a volume of approximately 50 to approximately 250m1, and preferably a volume of approximately IOOml. Naturally, the volume should be adjusted according to the size of the wound. Where compositions with a lower chlorine content are used, the volume used to wash the wound is preferably increased in order to achieve an equivalent therapeutic or prophylactic effect.

For convenience, the compositions according to the invention may be applied to the wound using a squeezy bottle, allowing the composition to be accurately directed.

Where the composition of the invention remains in contact with the wound, for example where a wound dressing is soaked in it, the volume of the composition that is applied to the wound may be reduced.

Without wishing to be bound by any particular theory, it is thought that, beyond its role as an antibiotic and nutrient, molecular oxygen may support vital processes in wound healing such as angiogenesis, cell motility and extracellular matrix formation.

In order to promote fibroblast proliferation and the production of coliagen, oxygen must be present in sufficient quantities. Additionally, active oxygen species contribute as cellular messengers to several important processes that support wound healing, such as signalling and promoting the inflammatory response, killing bacteria and promoting angiogenesis. The active oxygen species in the electrochemically activated water of the present invention are thought to add to the endogenous production of neutrophils, macrophages and endothehal cells, thus accelerating the -18 -In some embodiments of the present invention, the compositions of the present invention further comprise one or more therapeutically active agents, for administration to the wound with the anolyte of the electrochemically activated water. Suitable active agents include, for example, agents known to help fight infection, such as antibiotics, or those known to promote wound healing, such as hepatocyte growth factors, as well as agents which accelerate wound healing.

Alternatively, the compositions according to the present invention may be used in combination with one or more therapeutically active agents, such as agents known to help fight infection (for example, antibiotics), or those known to promote or accelerate wound healing (for example, hepatocyte growth factors). Preferably, the compositions of the invention and the therapeutically active agents are administered simultaneously, sequentially or separately.

As discussed above, the treatment of a wound includes preventing infection of the wound and the surrounding areas. Therefore, the treatment of a wound may also involve using the compositions according to the present invention to cleanse and! or wash uncompromised and/or uninjured skin, in order to disinfect such skin and therefore reduce the risk of contamination of the wound.

The present Invention also provides a composition comprising an anolyte of electrochemically activated water, for use in cleansing and/or washing uncompromised and/or uninjured skin, the composition having a chlorine content of no more than about SOpprn. The compositions used in this way may have the various features discussed above.

The wound healing compositions of the present invention comprising electrochemically activated water are non-toxic, ecologically friendly, shelf-stable and anti-microbial. This is in stark contrast to conventional biocides based on chlorine, which are highly oxidative in their action and rely on this property to kill bacteria. In contrast, it is thought that the mildly oxidative compositions of the present invention act gradually over an extended period of time to kill a broad spectrum of bacteria including antibiotic-resistant strains such as MRSA and VRE.

Claims

-19 -Claims 1. A composition comprising an anolyte of electrochemically

activated water for treating a wound, the composition having a chlorine content of no more than about SOppm.
2. A composition as claimed in claim 1, for treating or preventing a wound infection.
3 A composition as claimed in claim 2, wherein the infection is a bacterial infection.
4. A composition as claimed in claim 3, wherein the bacterial wound infection is caused by Methicilhn-resistant Stapbji/ococcus azireus or Vancomycin-resistant /5 Enterococcus.cpp.
5. A composition as claimed in any one of thc preceding claims, for use in promoting wound heahng.
6. A composition as claimed in claim 4, for increasing the supply of oxygen to a
7. A composition as claimed in any one of the preceding claims, wherein the composition further comprises a catholyte of electrochemically activated water.
8. A composition as claimed in any one of the preceding claims, wherein the composition has a pH of between about 6 and 8.
9. A composition as claimed in any one of the preceding claims, wherein the composition has a chlorine content of less than about 35ppm or less than about 8ppm.

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10. A composition as claimed in any one of the preceding claims, wherein the composition includes an active oxygen species in an amount between about 10 and 2Omg/l.
11. A composition as claimed in any one of the preceding claims, wherein the composition has a chlorine dioxide concentration of no more than about l0ppm.
12. A composition as claimed in any one of the preceding claims, wherein the composition has a hypochiorite concentration of no more than about lOppm
13. A composition as claimed in any one of the preceding claims, wherein the electrochemically activated water has a redox potential of at least about +900mV.
14. A composition as claimed in any one of the preceding claims, further comprising one or more therapeutically active agents.
15. A composition comprising an anolyte of electrochen-ucally activated water for cleansing uncompromised skin, the composition having a chlorine content of no more than about S0ppm.
16. Use of electrochemically activated water in the manufacture of a medicament for treating a wound, wherein the medicament comprises a composition as claimed in any one of claims 1-14.
17. A use as claimed in claim 16, wherein the medicament is for administration with one or more therapeutically active agents.
18. A wound dressing comprising a composition as claimed in any one of claims 1-14 for treating a wound.