Patent Description:
Electrochemically activated salt solutions are usually obtained by electrolysis of sodium chloride solutions. Electrochemically activated salt solutions are known as cleaning or disinfection agents e.g. in agriculture, dentistry, medicine and food industry. It can be used in applications like surface disinfection, e.g. of working plates, tables, floors, etc., for cold sterilizing procedures in agriculture, for the elimination of microbial organisms, for wash and laundry application, in swimming pools and even as prophylaxis against athletes food. The broad-spectrum antimicrobial properties of ECAS have been reviewed by Thorn et al.

<CIT> discloses a device for producing a biocidal solution by electrolytic treatment of an aqueous salt solution. <CIT> discloses an oxidative reduction potential water solution and its use as disinfectant of a wound treatment. <CIT> discloses an acidic ECAS having a pH from <NUM>-<NUM> exhibiting antimicrobial properties and its use e.g. in wound healing. <CIT> discloses ECAS generated by electrolysis of an aqueous solution, suitable for treatment of infectious and/or inflammatory conditions of the urinary bladder.

<CIT> discloses treatment of infections or inflammation by administering hypohalous acid to affected areas.

<CIT> discloses an acidic ECAS having a pH from <NUM> to <NUM> for use as an ophthalmic preparation.

<CIT> discloses an acidic ECAS having a pH from <NUM> to <NUM> for the treatment of an outer eye disorder selected from cataract, ocular keratitis, corneal neovascularization, epithelium deficiency, and chronic opacity.

<CIT> discloses two-phase pharmaceutical preparations comprising an active ingredient and an ECAS for medical applications. ECAS is also suggested as a carrier for the manufacture of pharmaceutical preparations.

<CIT> discloses a pharmaceutical composition with an active ingredient in one phase and a carrier substance comprising an ECAS in a separate phase.

Ocular infections may cause serious ocular problems with significant sight-threatening consequences if - mostly aggressive - therapy is not promptly instituted. For several years, cephalosporins and aminoglycosides have been used as first choice treatment for infectious eye diseases. However, problems associated with topical antibiotics and the emergence of antibiotic-resistant organisms have prompted interest in the search for therapeutic alternatives (Romanowski et al. , <NUM>, Willcox, <NUM>).

Also the use of preservatives, such as benzalkoniumchloride (BAK), in ophtalmics is recently debated due to allergic reactions. On the other hand, preservative-free medicaments are usually offered only in single-use units. Moreover, preservative-free formulations typically have an acidic pH value of less than <NUM>, while the recommended pH value of ophthalmica is neutral to slightly alkaline to avoid irritations of the eye and to enable high patients' compliance. More specifically, the average pH of tear film has been described as <NUM>-<NUM> (Lowther <NUM>).

Considering the above, there is an urgent need of new preparations for the treatment of eye infections which overcome the drawbacks of the known medicaments.

Thus, the object of the present invention is the provision of an effective medicament which is stable over a prolonged period of time and improves the patients' compliance by minimizing any harmful side effects, when applying the same.

In a first aspect, the present invention refers to an electrochemically activated salt solution (ECAS) comprising.

The ECAS of the invention preferably further comprises at least one salt of boric acid and/or at least one salt of phosphoric acid, more preferably at least one salt of phosphoric acid. In another embodiment the ECAS of the invention further comprises at least one salt of boric acid. In another embodiment, the ECAS of the invention further comprises at least one salt of boric acid and at least one salt of phosphoric acid.

Boric acid as an excipient has been reviewed by the European Medicines Agency.

Salts of boric acid are usually borates (BO<NUM><NUM>-). Salts of phosphoric acid may include phosphate (PO<NUM><NUM>-), hydrogenphosphate (HPO<NUM><NUM>-) and/or dihydrogen phosphate (H<NUM>PO<NUM>-). Suitable counterions of the above salts are alkali ions, such as sodium (Na+) and potassium (K+), ammonium (NH<NUM>+), or Ca<NUM>+. In a preferred embodiment the ECAS of the invention further comprises sodium dihydrogenphosphate and disodium hydrogenphosphate.

The (salt of) phosphoric acid - if present - is preferably present in a total amount of <NUM>-<NUM>/l, more preferably in a total amount of <NUM>-<NUM>/l. The (salt of) boric acid - if present - is preferably present in a total amount of <NUM> to <NUM>/l, more preferably in a total amount of <NUM>-<NUM>/l.

The electrochemically activated salt solution is preferably stable over one year, more preferably over two years, when stored in a closed high-density polyethylene (HDPE) container at <NUM>. It was surprisingly found that ECASs comprising at least one (salt of) boric acid and/or at least one (salt of) phosphoric acid may even improve the stability of the ECAS of the invention as compared to ECASs lacking at least one (salt of) boric acid and/or at least one (salt of) phosphoric acid. Moreover, it has been found that storage in high-density polyethylene material (HDPE) provided good stability as compared to other materials, such as low density polyethylene (LDPE) or polypropylene (PP).

In one embodiment, "stable" or "stability" in the sense of the present invention means that the redox potential of the ECAS of the present invention is reduced by <NUM>%, preferably <NUM>-<NUM>% at maximum after <NUM> months of storage under the respective storing conditions. Alternatively, the redox potential of the ECAS of the present invention is reduced by <NUM>%, preferably <NUM>-<NUM>%, at maximum after <NUM> months of storage under the respective storing conditions. Alternatively, the redox potential of the ECAS of the present invention is reduced by <NUM>%, preferably <NUM>-<NUM>%, at maximum after <NUM> months of storage under the respective storing conditions.

The redox potential can be determined via established methods known to the skilled person.

In a further aspect, the ECAS according to the present invention may contain hypochlorite ions and/or hypochlorous acid, particularly in a total concentration of <NUM> to <NUM>/l, more preferably in a total concentration of <NUM> to <NUM>/l.

The total content of chlorite and/or chlorate ions is preferably below toxic levels, e.g. less than <NUM>/l, more preferably <NUM>-<NUM>/l, even more preferably <NUM>-<NUM>/l.

Further, the total content of heavy metals and heavy metal ions in the ECAS according to the invention is preferably below toxic levels, e.g. less than <NUM>µg/g, preferably less than <NUM>µg/g, more preferably between <NUM> and <NUM>µg/g, and the content of each individual heavy metal and heavy metal ion is preferably less than <NUM>µg/g. Heavy metals and heavy metal ions may be or derive from silver, arsenic, gold, iridium, palladium, platinum, rhodium, thallium, cadmium, cobalt, mercury, lead, ruthenium, chromium, molybdenum, antimony, tin, copper, nickel, osmium, or vanadium. The heavy metal (ion) may be detected by ICP-MS analysis according to ISO <NUM>.

In a further aspect, the ECAS of the invention may contain at least one viscosity-increasing agent, such as a polymer. Any polymer may be used either organic or inorganic. Suitable polymers may be cellulose, cellulose derivatives, such as carboxymethyl cellulose (CMC), or hydroxypropyl methylcellulose (HPMC), polysaccharides, such as glucosaminoglycans, e.g. hyaluronic acid (HA), polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), silica gel, magnesium metasilicate and/or aluminium-metasilicate.

The ECAS of the invention preferably does not contain, i.e. is free of, an additional therapeutically active agent, such as a drug. It has surprisingly been found that the ECAS of the invention is effective in the treatment of eye infections without the need of additional therapeutically active agents.

The ECAS of the invention preferably does not contain, i.e. is free of, an additional preservative, such as BAK, sodium perborate, oxychloro complex, zinc borate complex, etc. It has surprisingly been found that the ECAS of the invention has sufficient disinfecting power per se to prevent microbial growth.

In a further aspect, the present invention relates to a process for producing an electrochemically activated salt solution (ECAS) as described above comprising the steps of.

The electrolysis reactor preferably includes a cylindrical cathode, which is mounted coaxially within a cylindrical anode. The cathode and the anode may be separated by a microporous membrane, wherein an electrical current is applied to the electrodes. The electrolysis is conducted at a current of <NUM>-<NUM> A, preferably at a current of <NUM>-<NUM> A.

The electrolysis reactor is preferably configured for continuous electrolysis. One or more of said reactors can be combined in parallel or serially.

The aqueous chloride solution used in step (i) preferably has a concentration of up to <NUM>/l, preferably <NUM>-<NUM>/l, in water for injection (sterile water).

The ECAS obtained in step (i) or (ii) may be diluted with an aqueous medium, preferably sterile water. The ECAS obtained in step (i) or (ii) may e.g. be diluted with an aqueous medium in a ratio of ECAS:aqueous medium of from <NUM>:<NUM> to <NUM>:<NUM>, preferably <NUM>:<NUM> to <NUM>:<NUM>.

In a further aspect, the present invention relates to a pharmaceutical preparation comprising an electrochemically activated salt solution (ECAS) of the invention and optionally at least one therapeutically effective agent. The pharmaceutical preparation according to the invention may comprise at least one pharmaceutically acceptable excipient. Pharmaceutically acceptable excipients may be selected from e.g. buffers, adjuvants, auxiliary agents, fillers, diluents, etc..

In another aspect, the electrochemically activated salt solution (ECAS) of the invention is for use in treating infections, particularly eye infections, e.g. caused by microbes such as bacteria, fungi and/or viruses. Bacterial and fungal infections might be caused by one or more species selected from the group consisting of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa, Acinetobacter calcoaceticus, Enterobacter aerogenes, Streptococcus anginosus, Streptococcus pyogenes, Candida albicans, Aspergillus brasiliensis, Aerratia marcescens and Acinetobacter pitii. Viral infections might be caused by viruses selected from the group consisting of adenoviruses, such as human adenovirus B and human adenovirus C, enteroviruses, such as enterovirus <NUM> or coxsackie viruses, and herpesviruses, such as Herpes simplex virus <NUM> and Herpes simplex virus <NUM>.

In a further aspect, the electrochemically activated salt solution (ECAS) of the invention can be particularly used for treating eye infections preferably for treating conjunctivitis, keratitis, blepharitis, endophthalmitis, more preferably keratitis and/or conjunctivitis, even more preferably conjunctivitis. It was surprisingly found that the ECAS of the invention revealed optimum efficacy in the treatment of bacterial conjunctivitis and bacterial keratitis by in vitro and in vivo studies without causing detrimental side-effects.

Thus, in a very preferred embodiment, the electrochemically activated salt solution (ECAS) of the invention can be used for treating conjunctivitis, e.g. caused by microbes, e.g. bacteria, fungi or viruses, more preferably for treating bacterial conjunctivitis.

Thus, in another preferred embodiment, the electrochemically activated salt solution (ECAS) of the invention can be used for treating keratitis, e.g. bacterial keratitis.

For treating eye infections the electrochemically activated salt solution (ECAS) of the invention may be administered topically onto the eye, the lacrimal sac and/or the lid. In a preferred embodiment, the ECAS of the invention may be administered onto the eye directly after infection.

The present invention shall be further illustrated in more detail but not limited by the following examples.

For the preparation of ECAS six combined electrolysis reactors (coaxial electrodes) were used. Saturated sodium chloride solution stored in a tank was applied through a valve at a predetermined ratio to a flow of pure water for injection e.g. with a flow rate of <NUM> I/min and then pumped through the reactors. The two activated solutions generated by the anode and the cathode were collected and mixed at a predetermined ratio to give pure ECAS.

Optionally, borate and/or phosphate salts were added to the pure ECAS before dilution with water for injection.

The ECAS obtained are summarized in the following table.

The stability of electrochemically activated salt solutions was evaluated by storing the obtained ECAS (see Table <NUM>) in a closed, high-density polyethylene (HDPE) container at <NUM>.

All ECAS show good antibacterial activity. The stability results, moreover, show that ECAS <NUM> and ECAS <NUM>, comprising salts of boric acid and salts of phosphoric acid, respectively, are more stable than ECAS <NUM> in terms of physicochemical parameters (Tab. 2a) and maintainance of antibacterial activity also after one year, as shown in detail in Tables 2c and 2d.

The in vitro antimicrobial activity of the ECAS <NUM> against bacteria, yeast and spores was tested. The tests were conducted in triplicate of each, a negative control (buffered sodium chloride-peptone solution), ECAS <NUM> and a reference product (Floxal®, eyedrops, <NUM>% ofloxacin, benzalkoniumchloride, water for injection), against <NUM> reference strains and <NUM> clinical isolates.

Each microorganism sample was diluted to a starting concentration of at least <NUM><NUM> - <NUM><NUM> CFU/ml. Then, the negative control, the ECAS <NUM> and the reference product were inoculated with <NUM> each and each sample was mixed. At time intervals of <NUM>, <NUM>, and <NUM> after inoculation, samples were taken and inactivated to determine the microbial survival.

The reduction in microorganism population was calculated by comparing the initial microbial concentration and the concentration at each incubation interval (both in CFU/mL). The results are shown in Table <NUM>.

The reference strains S. epidermidis, Acinetobacter calcoaceticus, Streptococcus anginosus, Streptococcus pyogenes, Pseudomonas aeruginosa, E. coli, Enterobacter aerogenes, Candida albicans and Aspergillus brasiliensis were susceptible to ECAS <NUM>. The ECAS <NUM> showed high activity (inhibition of more than <NUM> %) at time <NUM> against <NUM>/<NUM> microorganisms. An inhibition of more than <NUM>% was determined for <NUM> microorganisms.

After <NUM> the ECAS <NUM> showed activity (inhibition of more than <NUM> %) against all tested reference strains.

The reference strains S. epidermidis, Acinetobacter calcoaceticus, Streptococcus anginosus, Streptococcus pyogenes, Pseudomonas aeruginosa, E. coli and Enterobacter aerogenes were susceptible to the reference product Floxal®. The reference product showed high activity (inhibition of more than <NUM> %) at time <NUM> against <NUM>/<NUM> microorganisms. An inhibition of more than <NUM>% was determined for <NUM> microorganisms.

After <NUM> the reference product showed activity (inhibition of more than <NUM> %) against <NUM>/<NUM> tested reference strains.

Two microorganisms, Candida albicans and Aspergillus brasiliensis, remained viable (inhibition of less than <NUM>%) during up to <NUM> of incubation.

The <NUM> clinical isolates involved in the study were selected based on the incidence of the strains as collected from conjunctivitis in the medical microbiology laboratory within a one-month period. The most of them (<NUM>) were Staphylococcus aureus and MRSA, the rest, with lower incidence were E. coli (<NUM>), Pseudomonas aeruginosa (<NUM>), Acinetobacter pitii (<NUM>), and Serratia marcescenc (<NUM>).

The ECAS <NUM> showed high activity (inhibition of more than <NUM> %) at time <NUM> against <NUM>/<NUM> of tested isolates. An inhibition of more than <NUM>% was determined for <NUM>/<NUM> isolates of S. aureus/MRSA.

After <NUM> the ECAS <NUM> showed activity (inhibition of more than <NUM> %) against <NUM>/<NUM> isolates.

The reference product showed high activity (inhibition of more than <NUM> %) at time <NUM> against <NUM>/<NUM> tested S. aureus/MRSA isolates. An inhibition of more than <NUM>% was determined for <NUM>/<NUM> isolates.

At <NUM>, the reference product showed activity (inhibition of more than <NUM> %) against <NUM>/<NUM> tested isolates.

The ECAS <NUM> showed high activity (inhibition of more than <NUM> %) at time <NUM> against <NUM>/<NUM> of the tested E. coli isolates. An inhibition of more than <NUM>% was determined for <NUM>/<NUM> isolates.

The ECAS <NUM> showed activity (inhibition of more than <NUM> %) against <NUM>/<NUM> tested E. coli strains at <NUM> minutes.

The reference product showed high activity (inhibition of more than <NUM> %) at time <NUM> against <NUM>/<NUM> of the tested E. coli isolates. An inhibition of more than <NUM>% was determined for <NUM>/<NUM> isolates.

The reference product showed activity (inhibition of more than <NUM> %) against <NUM>/<NUM> tested isolates of E. coli at <NUM> minutes.

The ECAS <NUM> showed high activity of more than <NUM>% for <NUM>/<NUM> isolate of Pseudomonas aeruginosa at <NUM>.

At <NUM>, the ECAS <NUM> showed activity (inhibition of more than <NUM> %) against <NUM>/<NUM> tested Pseudomonas aeruginosa strain.

The reference product showed high activity (inhibition of more than <NUM> %) against <NUM>/<NUM> and an inhibition of more than <NUM>% against <NUM> isolates of Pseudomonas aeruginosa at time <NUM>.

The reference product showed activity (inhibition of more than <NUM> %) against <NUM>/<NUM> tested isolates of Pseudomonas aeruginosa at <NUM> minutes.

The ECAS <NUM> showed high activity (inhibition of more than <NUM> %) at time <NUM> against <NUM>/<NUM> isolates of the listed Gram negative bacteria.

At <NUM>, the ECAS <NUM> showed activity (inhibition of more than <NUM> %) against <NUM>/<NUM> isolates.

The reference product showed high activity (inhibition of more than <NUM> %) at time <NUM> against <NUM>/<NUM> of the listed Gram negative bacteria.

The results show that the ECAS <NUM> possesses strong antimicrobial activity. The spectrum of activity covers gram positive and gram negative bacteria, yeasts and molds. Inhibitory activity was detected against all reference strains (<NUM> strains) and against all of the clinical isolates from conjunctivitis (<NUM> strains) immediately after mixing of test inoculum (<NUM><NUM>-<NUM><NUM>) with the ECAS <NUM>. With the exception of two cases (Staphylococcus aureus GAOC <NUM>/<NUM> and Serratia marcescens DOC <NUM>) an inhibition of > <NUM>% was determined for all tested strains after <NUM> of incubation.

Differences in antimicrobial activity for the reference product Floxal® as compared to the ECAS <NUM> were particularly observed at time <NUM>. The inhibition determined for the ECAS <NUM> at time <NUM> was more effective than the inhibition with the reference product. Further, Aspergillus brasiliensis and Candida albicans were not susceptible to the reference product at a time interval of up to <NUM> minutes.

Vero cells were seeded in <NUM>-well plates and treated with dilutions of the ECAS <NUM> Dil. <NUM>:<NUM> and Dil. <NUM>:<NUM>, either:.

The cells were infected with the HSV-<NUM> strains Kupka and ANGpath at a multiplicity of infection (MOI) of <NUM>. The cells were collected <NUM> hours post infection (hpi) and the virus titer was determined by plaque assay. Briefly, the samples were serially diluted and plated onto one-day Vero cell-monolayers in <NUM>- or <NUM>-well tissue plates in duplicates. Afterwards, the cells were overlaid with <NUM>% methylcellulose in normal growth media. <NUM> days post infection, the cells were fixed and stained with <NUM>% crystal violet in <NUM>% ethanol, and the individual plaques were counted to determine the virus titer in each sample. Samples without treatment (Mock, negative control) and samples treated with ACV (Acyclovir, <NUM>µmol/l, reference control) were handled in the same manner. The test was performed in two independent experiments, where each of the samples was tested in parallel wells.

The HSV-<NUM> strains Kupka and ANGpath, were incubated at a MOI of <NUM> with dilutions of the ECAS <NUM> either Dil. <NUM>:<NUM> or Dil. <NUM>:<NUM>, in a final volume of <NUM>µl for either:.

Then cells, which had been seeded in <NUM>-well plates <NUM> hours before the infection, were infected with the above mentioned pre-incubated viruses. <NUM> hpi the cells were collected and the virus titer was determined by a plaque assay, as described above. Samples without treatment (Mock, negative control) and samples treated with Acyclovir (<NUM>µmol/l as reference control) were handled in the same manner. The test was performed in two independent experiments, where each of the samples was tested in parallel wells.

The ECAS <NUM> diluted <NUM>:<NUM> did not inhibit virus replication to the extent observed at a dilution <NUM>:<NUM>. Nevertheless, when the cells were treated during the infection, a titer reduction by <NUM> log10 PFU/ml (p ≤ <NUM>) was detected compared to mock-treated infected cells.

When the cells were treated with ACV, the maximal reduction in titer of the HSV-<NUM> strain Kupka, by <NUM> log10 PFU/ml (p ≤ <NUM>), was detected in cells treated <NUM> hpi.

Similar to the HSV-<NUM> strain Kupka, a significant reduction in titer of HSV-<NUM> ANGpath was detected, when the cells were treated with the ECAS <NUM> diluted <NUM>:<NUM> at all time points (<FIG>). Interestingly, the reduction in virus titer in cells treated with the ECAS (<NUM>:<NUM>) at all time points of treatment was even stronger in comparison to the cell treatment with ACV. The maximal reduction in titer of the HSV-<NUM> strain ANGpath, by <NUM> log10 PFU/ml (p ≤ <NUM>), was detected in cells treated with the ECAS <NUM> diluted <NUM>:<NUM> during infection (Tab.

The ECAS <NUM> diluted <NUM>:<NUM> did not inhibit virus replication to the extent observed at a dilution of <NUM>:<NUM>. Nevertheless, when the cells were treated at <NUM> hpi, a reduction in titer by <NUM> log10 PFU/ml (p ≤ <NUM>) compared to mock-treated infected cells was detected.

When the cells were treated with ACV, the maximum reduction in titer of the HSV-<NUM> strain ANGpath, by <NUM>, <NUM> and <NUM> log10 PFU/ml (p ≤ <NUM>), was detected in cells treated during infection, at 2hpi and at 6hpi, respectively.

A product is considered as mildly active against a virus in the case the virus titer is reduced at least by <NUM> log10 PFU/ml in comparison to the control. A strong antiviral effect of the product is considered when the virus titer is reduced by at least <NUM> log10 PFU/ml.

Our results indicate that treatment of cells with the ECAS <NUM> diluted <NUM>:<NUM> during the infection or at early times post infection could reduce the viral titer at least by <NUM> log10 PFU/ml and this potential of the ECAS is not dependent on the HSV-<NUM> strain. Thus, the ECAS <NUM> according to the invention has the potential to reduce the viral titer, when cells are treated during the infection or at early times post infection.

A total reduction in titer of the HSV-<NUM> strain Kupka was detected in infected cells treated with the ECAS <NUM> diluted <NUM>:<NUM> for all time points. Interestingly, the reduction in virus titer in infected cells treated with the ECAS <NUM> diluted <NUM>:<NUM> was even stronger in comparison to ACV treatment (<FIG>). The maximal reduction in titer of the HSV-<NUM> strain Kupka, by <NUM> log10 PFU/ml (p ≤ <NUM>), was detected in infected cells treated with the ECAS <NUM> diluted <NUM>:<NUM> for all time points and with the ECAS <NUM> diluted <NUM>:<NUM> for <NUM> hours (Tab.

A total reduction in titer of the HSV-<NUM> strain ANGpath was detected in infected cells treated with the ECAS <NUM> diluted <NUM>:<NUM> for <NUM>, <NUM> and <NUM>. Interesting, the reduction in virus titer in infected cells treated with the ECAS <NUM> diluted <NUM>:<NUM> at <NUM>-<NUM> was even stronger in comparison to ACV treatment (<FIG>). The maximal reduction in titer of the HSV-<NUM> strain ANGpath, by <NUM> log10 PFU/ml (p ≤ <NUM>), was detected in infected cells treated with the ECAS <NUM> diluted <NUM>:<NUM> for <NUM>, <NUM> and <NUM> (Tab.

The results clearly demonstrate that pre-incubation of virus with the ECAS <NUM> diluted <NUM>:<NUM> for <NUM> and more hours significantly reduces the titer of the HSV-<NUM> strain Kupka and ANGpath. Taken together, the ECAS <NUM> has the potential to directly influence the virus and mediate the inhibition of HSV-<NUM> replication, when the virus is pre-incubated with the test product for <NUM> hours and more before the infection.

The ECAS <NUM> has the potential to reduce the viral titer, when cells are treated with the ECAS <NUM> during the infection or at early times post infection. Moreover, the ECAS <NUM> has the potential to reduce the viral titer, when virus is treated with the ECAS <NUM> for two hours and more before the infection.

The results presented here clearly demonstrate that the ECAS <NUM> has basically the same antiviral effect as ACV, because the ECAS <NUM> can inhibit the virus replication, expressed as a reduction of viral titer, when cells are treated with the ECAS <NUM> during the infection or at early times post HSV-<NUM> infection, and inhibit the virus replication, expressed as a reduction of viral titer, when virus is treated with the ECAS <NUM> for <NUM> hours and more before HSV-<NUM> infection.

The antimicrobial effect of ECAS <NUM> in vivo was examined in eye balls of young New Zealand albino female rabbits. The conjunctiva of the rabbit right eye was injured under the condition of Isoflurane anesthesia. Staphylococcus aureus DOC <NUM>/<NUM> for inoculation was prepared from an overnight suspension after centrifugation, washing in saline and appropriate dilution to a suspension of <NUM><NUM> CFU and was instilled (injection in a volume of <NUM>µl) to mimic a branch injury. aureus was allowed to incubate for <NUM> hours.

After <NUM>, the infected rabbits' eyeballs were examined. All animals (<NUM> New Zealand albino female rabbits) showed no findings before the first treatment when examined according to Draize's eye test (cornea and iris, included) except of conjunctivitis as confirmed by ophthalmologists. Based on the grading of conjunctivitis (W. Behrens-Baumann and T. Begall, <NUM>) after <NUM> the animals were distributed into three groups (group I, II and III) in a way to obtain comparable conjunctive inflammatory scoring in each group.

The treatment of infected eyes started <NUM> hours after infection. Animals in group I were treated with normal sterile physiological saline (negative control/untreated group); animals in group II were treated with the ECAS <NUM> animals in group III were treated with commercial eye drops Floxal® containing ofloxacin (<NUM>% w/v in in water for injection, preservative-free; positive control). All three groups received <NUM>µL treatment solution per eyeball, respectively. The solution was sterilely instilled into the right conjunctival sac with a micropipette according to the schedule (every <NUM> hours for <NUM> days), spread on the entire eyeball and held for a few seconds. The left eye served as a control. The treatment for the different groups is summarized in Table <NUM>.

Ophthalmological examinations were performed daily just before the first treatment, except for the fourth day of treatment. The main parameter - conjunctival hyperaemia-was graded <NUM>, <NUM>, <NUM> or <NUM> for each quadrant according to Draize eye test (Table <NUM>) ( J. Draize et al. The scoring was performed by two persons; the left eye was used as a control. Ophthalmological examination before the first treatment and at the final ophthalmological examination included also the cornea and the iris.

Swabs were taken from the infected eye <NUM> hours after inoculation and every two days. The swabs were transported in sterile transport media before dilution and cultured using spread plate method. Residual antimicrobial agent in the recovery agar could artificially depress the recovery of viable cells. For this reason, the residual antibacterial activity was inactivated by dilution as described below.

Aliquots of <NUM> were serially diluted 10x in sterile buffered saline. The samples from rabbits treated with Floxal® were inactivated in buffered sodium chloride peptone solution, pH <NUM> + <NUM>% Tween + <NUM>% Lecithin + <NUM>% Histidine. Samples from each dilution were plated in triplicate by pipetting <NUM>µL on the Tryptone Soy agar and spreading, and incubated at <NUM> for <NUM>. The number of CFUs was counted.

The colony-forming units observed on each of the three plates/dilution per animal were counted. The obtained individual CFU values were transformed logarithmically prior to statistical assessment. Student's t-test was applied to compare the LogCFUs observed in the three treatment groups. A significance level of P < <NUM> was adopted. Mann Whitney (Wilcoxon's) test was adopted to compare the clinical score for conjunctiva in component groups. The statistical analysis was performed using Statgraphics™ Centurion software.

Twenty-four hours after inoculation the first ophthalmological examination was performed to check the onset of the infection process. The results are shown in Table <NUM>.

The examination just before the start of the treatment (<NUM>) confirmed the development of conjunctivitis in all animals. It was also confirmed that there were no pathological findings in the cornea and iris in any of the animals involved in the study (Table <NUM>).

The infected eyes were controlled six times. Results of the ophthalmological examinations expressed as summary score are presented in Table <NUM>. After the last evaluation (<NUM>) photographic documentation was done.

Summary score and average score for all time points are documented in <FIG>.

Both ECAS <NUM> and Floxal® treatment showed a reduction in the symptoms during the time after infection compared with the control which showed increased symptoms after <NUM>. Based on the clinical score results (Table <NUM>) it is inferred that after the first day of the treatment (<NUM>) there was a slight reduction in the symptoms of hyperaemia, chemosis and discharge in all three groups.

After two days of treatment (<NUM>) a progress of chemosis was not observed in ECAS <NUM> (II) and Floxal® (III) groups in contrast to the control group (Table <NUM>). In both treatment groups (II and III) the chemosis was in a reduced range.

After four days of treatment the ECAS2 group showed effective clinical cure in <NUM>/<NUM> animals (score <NUM>-<NUM>) whilst the Floxal® treated group showed effective clinical cure in <NUM>/<NUM> animals.

Eight days post infection (<NUM> dosing days) complete clinical cure was observed in <NUM>/<NUM> animals of the ECAS <NUM> group whereas in the Floxal® treated group absence of clinical slight symptoms of conjunctivitis was observed in <NUM>/<NUM> animals. The process of infection eradication was relatively fast not allowing to perform a comparison at more time points.

After two days of treatment (<NUM>) the treatment with the ECAS <NUM> reduced the number of S. aureus by approximately <NUM> log CFU compared to that at the start of the treatment (<FIG>). The reduction was not statistically significant compared to that of the untreated control at P = <NUM> (P = <NUM>) primarily due to the high variability of the data. The swabs were negative in <NUM>/<NUM> rabbits (Table <NUM>).

After two days of the treatment (<NUM>), Floxal® produced approximately <NUM> log reduction in CFU relative to the counts determined at the start of the treatment (<FIG>). The reduction was not statistically significant compared to that of the untreated control at P = <NUM> (P = <NUM>). The variability of outcoming data was substantial in this case too. The swabs were negative in <NUM>/<NUM> rabbits.

In this investigation, the focus lies on analyzing the activity of the ECAS <NUM> in comparison with that of Floxal® by using rabbits with Staphylococcus aureus induced conjunctivitis. The efficacy study was done in the right eye balls of young New Zealand albino female rabbits infected with log phase culture of the clinical isolate S. aureus DOC <NUM>/<NUM>. The anti-conjunctivitis efficacy was evaluated by monitoring the symptoms and scoring of each group. At days <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> ophthalmological evaluations were done, and the swabs tests for mean bacterial counts were taken every <NUM>nd day.

In the group treated with the ECAS there was a considerable treatment effect which distinguished from day <NUM> (<NUM>) on. Both in the ECAS <NUM> and Floxal® treated groups the conjunctival score clinically decreased when compared to the control group.

The clinical score results registered on day <NUM> (<NUM>) revealed clear differences between the treated and untreated groups accomplishing germ elimination.

Further, no evidence of local intolerance in the ECAS <NUM> group was observed.

Pseudomonas aeruginosa is one of the most commonly isolated pathogens from contact lens-associated ulcerative incidents. Patients infected with P. aeruginosa develop severe ulcers and often require more extensive treatments than patients with infections caused by other pathogens. Corneal destruction during P. aeruginosa infection is rapid, and perforation and/or loss of vision is possible within <NUM>.

The intrastromal injection of bacteria is not analogous, in terms of the route of inoculation, to the most common forms of human keratitis. The invasion of tissue by bacteria from the corneal surface is the more natural means of initiating infection. However, topical inoculations often fail to produce an infection or yield infections in an imprecise fashion (large variations in number of bacteria in the tissue) (O'Callaghan et al.

Because the rabbit cornea has been a standard model for numerous ocular studies, data can be extrapolated to the therapy of human keratitis (O'Brien et al. Studies of experimental bacterial keratitis have demonstrated that the tissue damage is mediated by a combination of bacterial host factors.

The aim of the study was to evaluate the effects of the ECAS in experimental keratitis. Intrastromal Pseudomonas aeruginosa was given to the right eye of <NUM> rabbits. The rabbits were divided equally into three treatment groups (n = <NUM>): saline (control group I), ECAS <NUM> (test product group II) and Floxal® (reference group III).

The treatment of Pseudomonas-infected corneas started <NUM> hours after infection based on clinical signs. Treatment products were administered every <NUM> with <NUM> doses in total. The same treatment schedule was applied in group IV for evaluation of non-infected rabbits with the ECAS treatment.

Group II (infected with treatment - II): animals received treatments with the ECAS <NUM>. <NUM>µl of ECAS <NUM> was sterilely instilled into the right conjunctival sac with a micropipette according to the schedule. The eye lids were gently closed for <NUM> - <NUM> seconds. The left eye served as the control.

Group III (infected with treatment - III): animals received treatments with Floxal® in a volume of <NUM>µl sterilely instilled into the right conjunctival sac with a micropipette according to the schedule. The eye lids were gently closed for <NUM> - <NUM> seconds. The left eye served as the control.

Group IV (not infected with treatment - IV): animals received treatments with <NUM>µl of ECAS <NUM> sterilely instilled into the right conjunctival sac with a micropipette according to the schedule. The eye lids were gently closed for <NUM> - <NUM> seconds. The left eye served as the control.

Directly before the first treatment, <NUM>, <NUM> and <NUM> after inoculation, the eyes were examined with a slit lamp to assess the infection development. One hour after the last application the rabbits were sacrificed by an overdosing of Thiopental and cornea were collected for bacterial count.

The corneas were aseptically removed, dissected, transferred to tubes, weighed and cut into multiple pieces. The tissues were homogenized in an ice bath by a tissue homogenizer at <NUM><NUM> rpm twice for <NUM> sec in <NUM> of sterile phosphate-buffered saline and aliquots were serially diluted 10x in sterile buffered sodium chloride peptone solution. The animals treated with the reference product were serially diluted in buffered sodium chloride peptone solution + <NUM>% Tween + <NUM>% Lecithin + <NUM>% Histidine for inactivation of residual reference product. Samples from each dilution were plated in triplicate by pipetting <NUM>µL on Tryptone Soy agar (TSA) and Cetrimid agar and spreading, and incubated at <NUM> for <NUM>. The viable CFUs were counted. The number of viable Pseudomonas aeruginosa was expressed per <NUM> of cornea (Table <NUM> and <FIG>).

To confirm that the infection process was located in the eye structures only and to exclude secondary contamination, swabs were collected from the conjunctive sack <NUM> hours after infection from all animals.

The treatment of rabbit eyes infected with Pseudomonas aeruginosa from <NUM> to <NUM> post infection with the ECAS <NUM> reduced the number of Pseudomonas aeruginosa organisms by approximately <NUM> log CFU/<NUM> cornea compared to that of the untreated control group (from <NUM>. 4x10<NUM> to <NUM>. 1x10<NUM>CFU/<NUM> cornea) (<FIG>). The % residual number of bacteria after treatment with ECAS2 was <NUM>% of the control group.

Floxal® reduced the number of bacteria from <NUM>. 4x10<NUM> to <NUM> CFU/<NUM> of cornea, i.e. to a residual % number of bacteria equivalent to < <NUM>% relative to the saline control. Although the bacteria % reduction generated by Floxal® was slightly higher than by the ECAS <NUM>, the difference between the Floxal® treated group and the ECAS <NUM> treated group was not statistically significant at P = <NUM>.

Claim 1:
Electrochemically activated salt solution (ECAS) comprising a content of total chlorine of between <NUM> and <NUM>/l, preferably <NUM>-<NUM>/l,
a content of chloride of between <NUM> and <NUM>/l, preferably <NUM>-<NUM>/l,
a redox potential of +<NUM> to +<NUM>,<NUM> mV, preferably +<NUM> to +<NUM>,<NUM> mV, more preferably + <NUM> to +<NUM>,<NUM> mV, more preferably +<NUM> to +<NUM>,<NUM> mV,
an osmolality of <NUM>-<NUM> mOsm/kg, preferably <NUM>-<NUM> mOsm/kg, more preferably <NUM>-<NUM> mOsm/kg,
a pH value of <NUM>-<NUM>, preferably <NUM>-<NUM>, and
at least one (salt of) boric acid and/or at least one (salt of) phosphoric acid.