ANTIMICROBIAL SUPERABSORBENT COMPOSITIONS

Abstract

A composition has an enzyme that is able to convert a substrate to release hydrogen peroxide; a substrate for the enzyme; and a superabsorbent component, such as a superabsorbent polymer. The composition is in the form of a powder and may form a gel on contact with water.

Claims

1. A composition comprising: an enzyme that is able to convert a substrate to release hydrogen peroxide; a substrate for the enzyme; and a superabsorbent component, wherein the composition is in the form of a powder.

2. A composition according to claim 1, wherein the superabsorbent component has an absorption capacity of at least 10 g/g.

3. A composition according to claim 1 or claim 2, wherein the superabsorbent component has an absorption capacity of at least 20 g/g.

4. A composition according to any preceding claim, wherein the superabsorbent component has an absorption capacity of at least 30 g/g.

5. A composition according to any preceding claim, wherein the superabsorbent component has an absorption capacity of at least 50 g/g.

6. A composition according to any preceding claim, wherein the superabsorbent component has an absorption capacity of at least 100 g/g.

7. A composition according to any preceding claim, wherein the superabsorbent component has an absorption capacity of at least 200 g/g.

8. A composition according to any preceding claim, wherein the superabsorbent component has an absorption capacity of at least 500 g/g.

9. A composition according to any preceding claim wherein the absorption capacity is in respect of deionised or distilled water.

10. A composition according to any of claims 1 to 8, wherein the absorption capacity is in respect of a 0.9% (by weight) saline solution.

11. A composition according to any preceding claim, wherein the superabsorbent component is a superabsorbent polymer.

12. A composition according to claim 11, wherein the superabsorbent polymer is anionic.

13. A composition according to claim 11 or 12, wherein the superabsorbent polymer is cross-linked.

14. A composition according to any of claims 11 to 13, wherein the superabsorbent polymer is polyacrylate or polyacrylamide.

15. A composition according to claim 14, wherein the superabsorbent polymer is sodium polyacrylate.

16. A composition according to any of claims 11 to 13, wherein the superabsorbent polymer is selected from the group consisting of: a hydrolysed cellulose-polyacrylonitrile; a starch-polyacrylonitrile co-polymer; a cross-linked co-polymer of maleic anhydride, such as ethylene maleic anhydride co-polymer; cross-linked carboxymethyl cellulose; polyvinyl alcohol co-polymer; and cross-linked polyethylene oxide.

17. A composition according to any preceding claim, wherein the powder has a mean and/or modal particle diameter of 3000 m or less.

18. A composition according to any preceding claim, wherein the powder has a mean and/or modal particle diameter of 2000 m or less.

19. A composition according to any preceding claim, wherein the powder has a mean and/or modal particle diameter of 1000 m or less.

20. A composition according to any preceding claim, wherein the powder has a mean and/or modal particle diameter of 500 m or less.

21. A composition according to any preceding claim, wherein the powder has a mean and/or modal particle diameter of 50 m or more.

22. A composition according to any preceding claim, wherein the powder has a mean and/or modal particle diameter of 100 m or more.

23. A composition according to any preceding claim, wherein the powder has a mean and/or modal particle diameter of 200 m or more.

24. A composition according to any preceding claim, wherein the powder contains less than 10% of particles with a diameter of 1000 m or more.

25. A composition according to any preceding claim, wherein the powder contains less than 10% of particles with a diameter of 50 m or less.

26. A composition according to any preceding claim, wherein the enzyme is a purified enzyme.

27. A composition according to any preceding claim, wherein the enzyme is an oxidoreductase enzyme.

28. A composition according to claim 27, wherein the enzyme is glucose oxidase.

29. A composition according to any preceding claim, wherein the substrate is a purified substrate.

30. A composition according to any preceding claim, wherein the substrate is a sugar.

31. A composition according to claim 30, wherein the substrate is glucose.

32. A composition according to any preceding claim, comprising a solute in the form of a sugar or sugar derivative having a solubility of at least 100 g/100 g water at 20 C. and 1 atm.

33. A composition according to claim 32, wherein the solute is a disaccharide or a monosaccharide.

34. A composition according to claim 33, wherein the solute is a monosaccharide.

35. A composition according to claim 34, wherein the monosaccharide is fructose.

36. A composition according to any preceding claim, which provides for sustained release of hydrogen peroxide for a period of at least twenty four hours, more preferably at least 48 hours, following dilution of the composition.

37. A composition according to any preceding claim, which provides for sustained release of hydrogen peroxide at a level of less than 2 mmol/litre and/or at level of at least 0.1 mmol/litre for a period of at least twenty four hours, following dilution of the composition.

38. A composition according to any preceding numbered paragraph, which is a pharmaceutical grade composition.

39. A composition according to any preceding numbered paragraph which is sterile.

40. A composition according to claim 30, wherein the composition has been sterilised by exposure to irradiation, preferably gamma irradiation, more preferably 10-70 kGy, more preferably 25-70 kGy, most preferably 35-70 kGy.

41. A composition according to any preceding claim which lacks catalase activity.

42. A composition according to any preceding claim which does not contain a peroxidase.

43. A composition according to any preceding claim, comprising a blood clotting agent.

44. A composition according to any preceding claim, which does not contain zinc oxide or contains essentially no zinc oxide.

45. A composition according to claim 34, comprising a coagulation factor, optionally fibrinogen and/or thrombin.

46. A composition according to any preceding claim, wherein hydrogen peroxide is present at a level less than 1 ppm or at a level less than 0.5 ppm.

47. A composition according to any preceding claim, comprising a freeze-drying protective agent.

48. A composition according to claim 38, wherein the freeze-drying protective agent is a sugar or polysaccharide.

49. A composition according to claim 39, wherein the freeze-drying protective agent is cyclodextrin or maltodextrin.

50. A composition according to any of claims 47 to 49, wherein the composition comprises 25 to 75% by weight, preferably 30 to 60% by weight, of freeze-drying protective agent.

51. A composition according to any preceding claim comprising 1 to 50% by weight of the superabsorbent component.

52. A composition according to any preceding claim comprising 2 to 30% by weight of superabsorbent component.

53. A composition according to any of claims 1 to 51, comprising 25% to 75% by weight of superabsorbent component.

54. A composition according to any preceding claim, comprising 50 to 95% by weight sugars.

55. A composition according to any of claims 1 to 53, comprising 25 to 75% by weight sugars.

56. A composition according to any of claims 47 to 49, comprising 25 to 75% by weight sugars, 25 to 75% by weight freeze-drying protective agent and 2 to 25% superabsorbent component, preferably 30 to 50% by weight sugars, 30 to 50% by weight freeze-drying protective agent and 4 to 25% superabsorbent component.

57. A composition according to any of claims 1 to 46, comprising 50 to 95% by weight sugars and 5 to 50% superabsorbent component.

58. A hydrogel comprising an enzyme that is able to convert a substrate to release hydrogen peroxide; a substrate for the enzyme; and a superabsorbent component.

59. A hydrogel according to claim 58, wherein the superabsorbent component is a superabsorbent polymer.

60. A hydrogel obtained or obtainable by contacting a composition according to any of claims 1 to 57 with an aqueous fluid.

61. A wound dressing which comprises a dressing material and a composition according to any of claims 1 to 57.

62. A hydrogel according to any of claims 58 to 60, in combination with a dressing material.

63. A wound dressing or hydrogel according to claim 61 or claim 62, wherein the dressing material is, or comprises, a gauze, bandage, tissue, film, gel, foam, hydrocolloid, alginate, hydrogel, a polysaccharide pastes, granules or beads.

64. A container comprising a composition as defined in any of claims 1 to 57.

65. A container according to claim 55 which is a sealed or air-tight container.

66. A method for making a composition as defined in any of claims 1 to 57, comprising contacting a superabsorbent component, preferably a superabsorbent polymer, with an enzyme that is able to convert a substrate to release hydrogen peroxide and a substrate for the enzyme.

67. A method according to claim 57, wherein the enzyme is a purified enzyme and the substrate is a purified substrate.

68. A method according to claim 66 or claim 67, wherein the superabsorbent component the enzyme and the substrate are in powder form.

69. A method according to claim 66 or claim 67, comprising freeze-drying a liquid mixture comprising the enzyme, the substrate and the superabsorbent component.

70. A method according to claim 69, wherein the liquid mixture comprises a freeze-drying protective agent.

71. A method according to claim 70, wherein the freeze-drying protective agent is cyclodextrin or maltodextrin.

72. A composition or hydrogel according to any of claims 1 to 60, for use as a medicament.

73. A composition or hydrogel according to any of claims 1 to 60, for prevention, treatment, or amelioration of a microbial infection.

74. Use of a composition or hydrogel according to any of claims 1 to 60, in the manufacture of a medicament for the prevention, treatment, or amelioration of a microbial infection.

75. A method of preventing, treating, or ameliorating a microbial infection, which comprises administering a composition or hydrogel according to any of claims 1 to 60, to a subject in need of such prevention, treatment or amelioration.

76. A use or method according to any of claims 73 to 75, wherein the microbial infection comprises a biofilm, or a microbe that is capable of forming a biofilm.

77. A use or method according to any of claims 73 to 76, wherein the microbial infection comprises a bacterium, preferably a Gram-negative bacterium, that is capable of forming a biofilm, or wherein the biofilm comprises any of the following species of bacteria, or wherein the microbe is any of the following species of bacteria: Pseudomonas aeruginosa; Acinetobacter baumannii, Methicillin-resistant Staphylococcus aureus (MRSA), or Methicillin-susceptible Staphylococcus aureus (MSSA), or wherein the microbial infection is a sinus infection, such as chronic rhinosinusitis (CRS), or wherein the microbial infection is a microbial lung infection, such as a Mycobacterium tuberculosis infection, or a Pseudomonas aeruginosa infection in a subject with cystic fibrosis.

78. A method of treating a wound, which comprises administering a composition or hydrogel according to any of claims 1 to 60, to a wound site.

79. A composition or hydrogel according to any of claims 1 to 60, for use in the treatment of a wound.

80. Use of a composition or hydrogel according to any of claims 1 to 60, in the manufacture of a medicament for treatment of a wound.

Description

[0192] Preferred embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings in which:

[0193] FIG. 1 shows a photograph of a superabsorbent powder according to an embodiment of the invention, prior to addition of water;

[0194] FIG. 2 shows the resulting gel following addition of 15 ml of water to a superabsorbent powder according to an embodiment of the invention, with a hydrogen peroxide test strip indicating hydrogen peroxide production;

[0195] FIG. 3 shows the gel of FIG. 2, in an inverted orientation.

[0196] FIG. 4 shows a gel following addition of 30 ml of water to a superabsorbent powder according to an embodiment of the invention;

[0197] FIG. 5 shows the gel of FIG. 4 in an inverted orientation;

[0198] FIG. 6 shows the particle size distributions of examples of superabsorbent powder compositions of the invention;

[0199] FIG. 7 shows a % strain sweep depicting the LVR for both extremes of current formulations including formulations which include maltodextrin and methylated -Cyclodextrin;

[0200] FIG. 8 the effect of dilution upon the physical properties of examples of gels of the invention;

[0201] FIG. 9 shows the effect of increasing the amount of cross-linked sodium polyacrylate on viscoelastic properties of examples of gels of the invention;

[0202] FIG. 10 shows the effect of dilution at a fixed frequency (1 Hz) upon the storage modulus of examples of gels of the invention;

[0203] FIG. 11 shows a comparison of storage modulus values at different dilutions between different examples of gels of the invention;

[0204] FIG. 12 is a graph showing the effect of compositions suitable for use in forming examples of superabsorbent powders of the invention comprising glucose, glucose oxidase and fructose (SyntheticRO) on the growth of planktonic MRSA, compared to Surgihoney, at various concentrations;

[0205] FIG. 13 is a graph showing the effect of sterile and non-sterile compositions suitable for use in forming examples of superabsorbent powders of the invention, comprising glucose, glucose oxidase and fructose (SyntheticRO) (buffered at pH 4.03) on the growth of planktonic MRSA, at various concentrations;

[0206] FIG. 14 is a graph showing the effect of sterile and non-sterile compositions suitable for use in forming examples of superabsorbent powders of the invention, comprising glucose, glucose oxidase and fructose (SyntheticRO) (unbuffered) on the growth of planktonic MRSA, at various concentrations;

[0207] FIG. 15 is a graph showing the effect of sterile and non-sterile compositions suitable for use in forming examples of superabsorbent powders of the invention, comprising glucose, glucose oxidase and fructose (SyntheticRO) (buffered at pH 7.04) on the growth of planktonic MRSA, at various concentrations;

[0208] FIG. 16 is a table showing the effect of sterile and non-sterile compositions suitable for use in forming examples of superabsorbent powders of the invention comprising glucose, glucose oxidase and fructose, on the MIC and MBC of planktonic MRSA, at various concentrations;

[0209] FIG. 17 shows the effect of compositions suitable for use in forming examples of superabsorbent powders of the invention, comprising glucose, glucose oxidase and fructose (SyntheticRO) on the growth of planktonic MRSA, compared to SurgihoneyRO, at various concentrations;

[0210] FIG. 18 shows the effect of SyntheticRO on the MIC and MBC of planktonic MRSA, compared to SurgihoneyRO, at various concentrations;

SPECIFIC EXAMPLES

Example 1Synthesis of Superabsorbent Powder

[0211] SurgihoneyRO (Sachet) or SyntheticRO (a mixture of purified glucose oxidase, purified glucose and purified fructose; see example 5) and either methylated -Cyclodextrin (CycloLab R&D, UK) or Maltodextrin (Sigma Aldrich, UK) were first weighed out in equal proportions (50:50 ratio).

[0212] The desired amount (0.5, 1, 2 or 3 g) of cross-linked sodium polyacrylate (Sigma Aldrich, UK) was also weighed out.

[0213] All three components were then mixed together until a homogenous formulation was achieved.

[0214] This formulation was then placed inside a freezer mill tube and submerged in liquid nitrogen for approximately 1 minute. The freezer mill tube was then placed in the freezer mill (SPEX SamplePrep). The freezer mill was run at a rate of 30 cycles per second for a total time of 3 minutes.

[0215] For compositions containing SurgihoneyRO, it was found that milling the mixture first allowed for a more complete drying process.

[0216] The samples were then transferred into the freeze drying chamber (Frozen in Time). The freeze drier cold trap was set to 55 C. and was at a pressure of 4.010.sup.4 mbar. The sample was freeze dried for a total of 48 hours.

[0217] The samples were removed and sieved using 1000 m and 500 m gratings. Any powder that remained in the sieves was crushed using a pestle and mortar and ran through the sieves again. The powder was then sealed in a pot containing silica gel beads which act as a desiccant.

Example 2Formation of Gels

[0218] To demonstrate formation of gels, water was added to a powder containing 40:60 SurgihoneyRO to cyclodextrin composition containing 3 wt % sodium polyacrylate.

[0219] FIG. 1 shows 1 g of the powder prior to addition of water, in a weighing boat.

[0220] FIG. 2 shows the resulting gel following addition of 15 ml of water. It also shows a hydrogen peroxide test strip indicating the production of hydrogen peroxide by the gel. FIG. 3 shows the same gel, but in an inverted orientation. This demonstrates how the gel may readily adhere to a surface.

[0221] FIG. 4 shows the gel following addition of 30 ml of water, and FIG. 5 shows the same gel in an inverted orientation.

Example 3Particle Size Analysis

[0222] An instrument called QICPIC (Sympatec, UK) was employed, which uses of dynamic image analysis to size particles. High speed image analysis used a pulsed light source with illumination times of less than 1 nanosecond. The particles are optically frozen while a high-resolution, high-speed camera captures the particle projections. Algorithms built into the instrument software evaluate the particles giving statistically relevant results. The following parameters were used in order to determine particle size: [0223] Calculation mode: EQPCthis mode is used to calculate the diameter of a circle that has the same area as the projection area of the particle. [0224] Trigger condition: start 0s, valid 300 s [0225] Dispersing method: 2 mm 25% 4 mm [0226] Frame rate: 100 fps [0227] Height of fall: 40.00 cm [0228] Feeder: Vibrate [0229] Feed rate: 25.00% [0230] Gap height: 2.00 mm

[0231] The amount of superabsorbent polymer in the compositions and the type of freeze-drying protective agent was varied in order to establish the impact of varying these parameters on the properties of the compositions.

[0232] The following compositions were tested, and their peak particle distributions and sphericities were established.

[0233] A superabsorbent reactive oxygen powder containing 47.6 wt. % methylated -Cyclodextrin, 47.6 wt. % SurgihoneyRO and 4.8 wt. % cross-linked sodium polyacrylate. [0234] This composition contains a peak particle size distribution at 204.5 m and a peak sphericity distribution at 0.9. [0235] A superabsorbent reactive oxygen powder containing 45.5 wt. % methylated -Cyclodextrin, 45.5 wt. % SurgihoneyRO and 9.1 wt. % cross-linked sodium polyacrylate. [0236] This composition contains a peak particle size distribution at 204.5 m and a peak sphericity distribution at 0.9. [0237] A superabsorbent reactive oxygen powder containing 41.7 wt. % methylated -Cyclodextrin, 41.7 wt. % SurgihoneyRO and 16.7 wt. % cross-linked sodium polyacrylate. [0238] This composition contains a peak particle size distribution at 186.4 m and a peak sphericity distribution at 0.9. [0239] A superabsorbent reactive oxygen powder containing 38.5 wt. % methylated -Cyclodextrin, 38.5 wt. % SurgihoneyRO and 23.1 wt. % cross-linked sodium polyacrylate. [0240] This composition contains a peak particle size distribution at 204.5 m and a peak sphericity distribution at 0.9. [0241] A superabsorbent reactive oxygen powder containing 38.5% methylated -Cyclodextrin, 38.5% wt. % SyntheticRO and 23.1 wt. % cross-linked sodium polyacrylate [0242] This composition contains a peak particle size distribution at 540.5 m and a peak sphericity distribution at 0.82. [0243] A superabsorbent reactive oxygen powder containing 47.6 wt. % maltodextrin, 47.6 wt. % SurgihoneyRO and 4.8 wt. % cross-linked sodium polyacrylate. [0244] This composition contains a peak particle size distribution at 405.7 m and a peak sphericity distribution at 0.85. [0245] A superabsorbent reactive oxygen powder containing 45.5 wt. % maltodextrin, 45.5 wt. % SurgihoneyRO and 9.1 wt. % cross-linked sodium polyacrylate. [0246] This composition contains a binomial distribution with peak particle size distributions at 445.0 m and 2107.4 m, a peak sphericity distribution at 0.85. [0247] A superabsorbent reactive oxygen powder containing 41.7 wt. % maltodextrin, 41.7 wt. % SurgihoneyRO and 16.7 wt. % cross-linked sodium polyacrylate, [0248] This composition contains a peak particle size distribution at 445.0 m a peak sphericity distribution at 0.85. [0249] A superabsorbent reactive oxygen powder containing 38.5 wt,% maltodextrin, 38.5 wt. % SurgihoneyRO and 23.1 wt. % cross-linked sodium polyacrylate. [0250] This composition contains a binomial distribution with peak particle size distributions at 445.0 m and 2107.4 m a peak sphericity distribution at 0.85. [0251] A superabsorbent reactive oxygen powder containing 38.5 wt. % maltodextrin, 38.5 wt. % SyntheticRO and 23.1 wt. % cross-linked sodium polyacrylate. [0252] The composition contains a polymodal distribution with peak particle size distributions at 540.5 m, 968.4 m and 1428.5 m; and two peak sphericity distribution at 0.45 and 0.85.

[0253] FIG. 6 a) illustrates the particle size distributions of each composition containing -cyclodextrin sodium polyacrylate and SurgihoneyRO/SyntheticRO. FIG. 6 b) illustrates the particle size distributions of each composition containing maltodextrin, sodium polyacrylate and SurgihoneyRO/SyntheticRO.

[0254] The results obtained suggest the following: [0255] Increasing the wt % of cross-linked sodium polyacrylate may not affect particle size. [0256] Compositions containing methylated -cyclodextrin may have a smaller average particle size than those that contain maltodextrin. [0257] Formulations that contain methylated -cyclodextrin may produce more spherical particles. [0258] Formulations containing Maltodextrin appear to aggregate or agglomerate to form larger particles post-sieving.

Example 4Gel Rheology Analysis

[0259] Firstly the linear viscoelastic region (LVR) was determined for all of the tested powder gels. The LVR is determined so that the material behaves linearly and an out of phase sinusoidal shear stress response is produced. This was achieved by conducting a strain sweep on a Rheometer (TA Instruments, UK) using a 40 mm steel sand blasted plate geometry in parallel to another sand blasted steel plate.

[0260] FIG. 7 shows a % strain sweep depicting the LVR for both extremes of tested formulations including formulations which include maltodextrin (MD) and methylated -Cyclodextrin (CD).

[0261] The strain sweep was conducted under the following conditions: [0262] % strain range was set logarithmically from 0.01 to 50.0 with 10 points measured per decade. [0263] Temperature set to 34 C. relevant to the final topical application with an equilibration time of 2 minutes. [0264] The frequency was kept constant at 1 Hz [0265] Geometry gap was set at 1000 m

[0266] The strain sweep identified a % strain that fell into the LVR for all of the samples; this was found to be 0.5% strain.

[0267] Frequency sweeps were then carried out at this % strain and the following conditions: [0268] Frequency range was set logarithmically from 0.1 and 100 Hz with 10 points measured per decade. [0269] Temperature set to 34 C. relevant to the final topical application with an equilibration time of 2 minutes.

[0270] The same compositions as those in Example 3 were used to form gels by adding varying amounts of water (5 ml, 10 ml or 20 ml).

[0271] FIG. 8 a) shows the effect of dilution upon the physical properties of the gel formed from a composition containing 38.5 wt. % methylated -cyclodextrin, 38.5 wt. % SurgihoneyRO and 23.1 wt. % cross-linked sodium polyacrylate, at a range of frequencies. FIG. 8 b) shows the same composition but with syntheticRO, rather than SurgihoneyRO.

[0272] The results indicate how shows how the gels formed may be more elastic than viscous (higher G (storage modulus) than G (loss modulus)), over the range of frequencies; and how there may be a low frequency dependency. Similar effects were observed for the other compositions.

[0273] FIG. 9 shows the effect of increasing the amount of cross-linked sodium polyacrylate in maltodextrin: SurgihoneyRO/SyntheticRO compositions containing 4.8 wt. %, 9.1 wt. %, 16.7 wt. % and 23.1 wt. % upon the storage modulus (G). The gels were formed by adding 5 ml of distilled water. FIG. 9 shows how an increase in cross-linked sodium polyacrylate may increase the stiffness of the gel that is formed. Similar effects were observed for the other compositions.

[0274] FIG. 10 shows the effect of dilution at a fixed frequency (1 Hz) upon the storage modulus of the gel containing varying amounts of cross-linked sodium polyacrylate in maltodextrin: SurgihoneyRO/SyntheticRO formulations.

[0275] FIG. 11 a) shows a comparison of storage modulus values at different dilutions between gels formed from compositions containing maltodextrin: SurgihoneyRO and compositions containing methylated -cyclodextrin: SurgihoneyRO, the composotions containing 16.7 wt. % cross-linked sodium polyacrylate. FIG. 11 b) shows results from the same formulations, but which contain SyntheticRO rather than SurgihoneyRO.

[0276] The results obtained suggest the following: [0277] An increase in cross-linked sodium polyacrylate may increase the stiffness of the gel; [0278] There is a low frequency dependency; [0279] Samples may be more elastic than viscous; [0280] Gels containing SyntheticRO may have a higher G and G than those which contain SurgihoneyRO; [0281] There may be no significant difference between the rheology of the formulations that contain maltodextrin or cyclodextrin; [0282] Cyclodextrin-based formulations may dissolve more readily upon application to water than those which contain maltodextrin.

Example 5Synthetic Honey Compositions (Also Known as SyntheticRO)

[0283] Samples with batch number RO contain no glucose oxidase.

[0284] Samples with batch number RO1 contain 50 ppm glucose oxidase.

[0285] Samples with batch number RO2 contain 1000 ppm glucose oxidase.

[0286] A. pH 4.03 Buffered Samples

[0287] A1 Batch no NB01p43RO [0288] Non sterile

TABLE-US-00001 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 4.03 17.0%

[0289] Description

[0290] Non sterile base buffered saccharide solution.

[0291] A2. Batch no NBO1p43RO [0292] Sterile

TABLE-US-00002 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 4.03 17.0%

[0293] Description Sterile base buffered saccharide solution

[0294] A3. Batch no NBO1p44RO1 [0295] Non sterile

TABLE-US-00003 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 4.03 17.0%

[0296] Description

[0297] Non sterile base buffered RO1 saccharide solution.

[0298] A4. Batch no NB01p44RO1 [0299] Sterile

TABLE-US-00004 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 4.03 17.0%

[0300] Description

[0301] Sterile base buffered RO1saccharide solution

[0302] A5. Batch no NBO1p44RO2 [0303] Non sterile

TABLE-US-00005 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 4.03 17.0%

[0304] Description

[0305] Non sterile base buffered RO2 saccharide solution.

[0306] A6. Batch no NBO1p43RO2 [0307] Sterile

TABLE-US-00006 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 4.03 17.0% GOX enzyme N/A

[0308] Description Sterile base buffered RO2 saccharide solution

[0309] B. Unbuffered Samples

[0310] B1. Batch no NB01p51RO [0311] Non sterile

TABLE-US-00007 Material Weight fraction Fructose 52.0% Glucose 31.0% Water 17.0%

[0312] Description

[0313] Non sterile base buffered saccharide solution.

[0314] B2. Batch no NB01p51RO [0315] Sterile

TABLE-US-00008 Material Weight fraction Fructose 52.0% Glucose 31.0% Water 17.0%

[0316] Description Sterile base buffered saccharide solution

[0317] B3. Batch no NB01p51RO1 [0318] Non sterile

TABLE-US-00009 Material Weight fraction Fructose 52.0% Glucose 31.0% Water 17.0%

[0319] Description

[0320] Non sterile base buffered RO1 saccharide solution.

[0321] B4. Batch no NB01p51RO1 [0322] Sterile

TABLE-US-00010 Material Weight fraction Fructose 52.0% Glucose 31.0% Water 17.0%

[0323] Description

[0324] Sterile base buffered RO1 saccharide solution

[0325] B5. Batch no NB01p51RO2 [0326] Non sterile

TABLE-US-00011 Material Weight fraction Fructose 52.0% Glucose 31.0% Water 17 0%

[0327] Description

[0328] Non sterile base buffered RO2 saccharide solution. [0329] B6. Batch no NB01p51RO2

[0330] Sterile

TABLE-US-00012 Material Weight fraction Fructose 52.0% Glucose 31.0% Water 17.0%

[0331] Description

[0332] Sterile base buffered RO2 saccharide solution

[0333] C. pH 7.04 Buffered Samples

[0334] C1. Batch no NBO1p57RO [0335] Non sterile

TABLE-US-00013 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 7.04 17.0%

[0336] Description

[0337] Non sterile base buffered saccharide solution.

[0338] C2. Batch no NBO1p57RO [0339] Sterile

TABLE-US-00014 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 7.04 17.0%

[0340] Description

[0341] Sterile base buffered saccharide solution

[0342] C3, Batch no NBO1p57RO1 [0343] Non sterile

TABLE-US-00015 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 7.04 17.0%

[0344] Description

[0345] Non sterile base buffered RO1 saccharide solution.

[0346] C4. Batch no NBO1p57RO1 [0347] Sterile

TABLE-US-00016 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 7.04 17.0%

[0348] Description

[0349] Sterile base buffered RO1saccharide solution

[0350] C5. Batch no NB01p57RO2 [0351] Non sterile

TABLE-US-00017 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 7.04 17.0%

[0352] Description

[0353] Non sterile base buffered RO2 saccharide solution.

[0354] C6. Batch no NB01p57RO2

TABLE-US-00018 Material Weight fraction Fructose 52.0% Glucose 31.0% 50 mMol Citric acid/NaOH buffer pH 7.04 17.0%

[0355] Description

[0356] Sterile base buffered RO2 saccharide solution

Example 6Efficacy of Synthetic Honey Compositions Against Planktonic MRSA

[0357] MIC and MBC were assessed for the RO1 samples (containing 50 ppm glucose oxidase) and compared to Surgihoney (also containing 50 ppm glucose oxidase). See Andrews J. M. Journal of Antimicrobial Chemotherapy (2001) 48, suppl. S1, 5-16.

[0358] The results are shown in FIGS. 1 to 5.

[0359] The results show that, like Surgihoney, synthetic compositions containing glucose, glucose oxidase and fructose are able to inhibit microbial growth.

[0360] Out of all of synthetic compositions, the synthetic composition buffered at pH7.04 had the most effective MIC. Sterilised compositions were more effective than non-sterilised compositions, and synthetic composition buffered at pH7.04 synthetic had the most effective MBC when compared to other synthetic compositions and even when compared to SurgihoneyRO.

[0361] FIGS. 17 (a to d) and 18 show MIC and MBC results including SurgihoneyRO (RO2) samples and synthetic RO2 samples.