Vancomycin eye drops

Abstract

A medicinal eye drop formulation comprising 10 mg / mL (±5%) to 25 mg / mL (±5%) Vancomycin hydrochloride or, in each case, an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt of Vancomycin, Tryptophan, Mannitol and Methylcellulose for use in treating eye infection in a human subject.

Description

[0001] TITLE

[0002] Vancomycin Eye Drops

[0003] FIELD OF INVENTION

[0004] This invention relates to an eye drop medication comprising Vancomycin.

[0005] BACKGROUND

[0006] Vancomycin is a glycopeptide antibacterial agent used for treating various infections. It has for example been used as eye drops to treat serious or resistant infections of the cornea and / or conjunctiva. It acts to prevent the growth and multiplication of bacteria that cause these. The chemical structure of Vancomycin is shown below-

[0007] Vancomycin eye drops have been previously formulated to include a preservative, for example Benzalkonium chloride, which is considered necessary to enhance bacterial suppression and / or shelf-life. However, a problem is that many preservatives, especially those commonly used in medicine, can be undesirably irritating to the eyes. For this reason it would be desirable to avoid or minimise the use of such preservatives, and also for ease of manufacture. However, the upside of omitting these has been seen as outweighed by the downside of reduced bacterial suppression or shelf-life

[0008] OBJECT

[0009] It is an object of preferred embodiments of the invention to provide a medicinal eye drop formulation that goes at least some way to addressing the above. However, it should be appreciated that the object of the invention in its broadest form is more general, simply being to provide a useful choice.

[0010] DEFINITIONS

[0011] The term “comprises” or “has”, when used in this document in relation to one or more components or features, should not be seen as excluding the option of additional unmentioned components or features. The same applies to derivative terms such as “comprising” and “having”.

[0012] The term “consisting of’, or “consists of’, when used in this document in relation to a combination of components or features means that there are no further components or features in the combination.

[0013] This document includes references to various amounts of Vancomycin hydrochloride, and also to equivalent amounts of Vancomycin free base or equivalent amounts of an alternative salt of Vancomycin. Therefore, when reading the claim for the free base the amount thereof should be scaled down to account for the fact that it does not have the hydrochloride component. For example, 10 or 25 mg / mL of Vancomycin hydrochloride should be taken as equivalent to 9.8 or 23.4 mg / mL, respectively, of Vancomycin free base. It also means that when reading the claim for the alternative salt the amount thereof should be scaled up or down to account for the fact that its salt component may have a different weight to hydrochloride.

[0014] A reference to ±5% means up to ±5%. For example, it encompasses amounts that are 0%, 1%, 2%, 3% 4% or 5% more or less than the number given.

[0015] SUMMARY OF INVENTION

[0016] Use in Manufacturing

[0017] In one aspect, the invention comprises the use of -

[0018] • 10 mg / mL (±5%) to 25 mg / mL (±5%) Vancomycin hydrochloride or, in each case, an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt of Vancomycin;

[0019] • Tryptophan;

[0020] • Mannitol;

[0021] • Methylcellulose; and • Water; in the manufacture of a medicament in the form of an eye drop formulation for use in treating an eye infection in a subject caused by one or more of S. Aureus, P Aeruginosa, MRSA1, S. Pneumoniae, and S. Epidermidis.

[0022] Composition for use in Treating Eye Infection

[0023] In a further aspect, the invention comprises a medicament in the form of an eye drop formulation for use in treating an eye infection in a subject, comprising-

[0024] • 10 mg / mL (±5%) to 25 mg / mL (±5%) Vancomycin hydrochloride or, in each case, an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt of Vancomycin;

[0025] • Tryptophan;

[0026] • Mannitol;

[0027] • Methylcellulose; and

[0028] • Water; wherein the infection is caused by one or more of S. Aureus, P Aeruginosa, MRSA, S. Pneumoniae, and S. Epidermidis.

[0029] Options

[0030] The following options, or any combination thereof, are applicable to any or all of the above aspects, except to the extent that an option is already expressed above as a component of the Aspect in view.

[0031] Optionally the formulation does not contain any Benzalkonium chloride.

[0032] Optionally the formulation comprises Tryptophan in a sufficient amount to stabilise the formulation.

[0033] Optionally the Tryptophan is L-Tryptophan.

[0034] Optionally the Vancomycin hydrochloride is in the amount 10 mg / mL or 25 mg / mL .

[0035] Optionally the formulation comprises:

[0036] 1Methicillin-resistant Staphylococcus aureus. a) 25 mg / mL (±5%) Vancomycin hydrochloride; b) 0.77 mg / mL (±5%) Tryptophan; and c) water.

[0037] Optionally the formulation comprises: a) 10 mg / mL (±5%) Vancomycin hydrochloride; b) 0.31 mg / mL (±5%) Tryptophan; and c) water.

[0038] Optionally the formulation comprises or consists of: a) 25 mg / mL (±5%) Vancomycin hydrochloride; b) Tryptophan (eg in the amount 0.77 mg / mL ±5%); c) Mannitol (eg in the amount 3.0 mg / ml ±5%); d) Methylcellulose (eg in the amount 0.5 mg ±5%); and e) Water.

[0039] Optionally the formulation comprises or consists of: a) 10 mg / mL (±5%) Vancomycin hydrochloride; b) Tryptophan (eg in the amount 0.31 mg / mL ±5%); c) Mannitol (eg in the amount 3.0 mg / mL ±5%); d) Methylcellulose (eg in the amount 0.5 mg / mL ±5%); and e) Water.

[0040] Optionally in each case the formulation is for use in treating eye infections caused by one or more of: a) S. Aureus; b) P Aeruginosa,; c) MRSA; d) S. Pneumoniae; and e) S. Epidermidis.

[0041] Optionally the formulation is a solution or suspension.

[0042] Optionally the formulation has a pH of 2.5 - 4.5. Optionally the formulation has a pH of 3 - 4.

[0043] Optionally the formulation has a pH of 3.5 ±5%.

[0044] Optionally the formulation comprises sufficient acid or base to bring it to the above pH or pH range.

[0045] Optionally the subject is human.

[0046] Optionally the formulation does not have any or all of the following:

[0047] • Benzododecinium bromide;

[0048] • Sodium perborate;

[0049] • Polycatonic polymer;

[0050] • Polyquaternium-1 ;

[0051] • Polyquaternium-42;

[0052] • Purite;

[0053] • Sodium chlorite;

[0054] • SofZia;

[0055] • Sodium Perborate; and

[0056] • OcuPure.

[0057] Optionally the formulation is preservative free.

[0058] Optionally the alternative salts are selected from Vancomycin sulfate and Vancomycin phosphate.

[0059] Method of Treatment (I)

[0060] In a further aspect, the invention comprises a method of treating an eye infection in a subject caused by one or more of S. Aureus, P Aeruginosa, MRSA, S. Pneumoniae, and S. Epidermidis, comprising administering to an eye of the subject a formulation according to, or manufactured according to the use of, any of the above Aspects / options.

[0061] Method of Treatment (II)

[0062] A method of treating a bacterial eye infection in a subject comprising administering a formulation according to, or manufactured according to the use of, any of the above Aspects / options, wherein the eye is not exposed to benzalkonium chloride for the entire period that the eye is infected.

[0063] Method of Treatment (III)

[0064] In a further aspect, the invention comprises a method of treating an eye infection in a subject suffering from an ocular bacterial infection, the method comprising administering to an eye of the subject an aqueous eyedrop formulation comprising 10 - 50 mg / ml Vancomycin hydrochloride, or an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt of Vancomycin, and tryptophan, wherein the formulation does not contain benzalkonium chloride. The formulation may be according to, or may have been manufactured according to the use of, any of the above Aspects / options.

[0065] Method of Treatment (IV)

[0066] A method for treating a patient having an eye infection caused by one or more of Aureus, P Aeruginosa, MRSA, S. Pneumoniae, and S. Epidermidis, the method comprising administering 0.05 to 0.1 ml (±5%) of an aqueous formulation comprising 10 mg / mL (±5%) or 25 mg / mL (±5%) Vancomycin hydrochloride or, in each case, an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt of Vancomycin, and Tryptophan, wherein the formulation does not comprise benzalkonium chloride. The formulation may be according to, or may have been manufactured according to the use of, to any of the above Aspects / options.

[0067] Optionally, for Methods I, II, III and IV, the formulation is administered as 1-2 eye drops per eye, each drop having a volume of 0.05 mL ±5%.

[0068] Optionally for Methods I, II, III and IV, the total dose per administration for the 10 mg / ml Vancomycin hydrochloride is 0.4 - 1.2 mg of Vancomycin hydrochloride (or an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt if substituted for the Vancomycin hydrochloride).

[0069] Optionally for Methods I, II, III and IV, the total dose per administration for the 25 mg / ml Vancomycin hydrochloride is 1.0 - 3.0 mg of Vancomycin hydrochloride (or an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt if substituted for the Vancomycin hydrochloride). Optionally, for Methods I, II, III and IV, the formulation is administered 1 , 2, 3 or 4 times each day.

[0070] Optionally in each case the administration may be self-administration or may be administration to the subject by someone else.

[0071] DRAWINGS / GRAPHS

[0072] Some preferred embodiments of the invention will now be described by way of example and with reference to the following drawings, of which:

[0073] Figure 1 graphically indicates the results of trials on Tryptophan containing test samples of Vancomycin for suppression of the bacteria P Aeruginosa;

[0074] Figure 2 graphically indicates the results of trials on Tryptophan containing test samples of Vancomycin for suppression of the bacteria MRSA;

[0075] Figure 3 graphically indicates the results of trials on Tryptophan containing test samples of Vancomycin for suppression of the bacteria S. Aureus; and

[0076] Figure 4 graphically indicates the results of further trials on Tryptophan free test samples of Vancomycin for suppression of the bacteria P Aeruginosa.

[0077] DETAILED DESCRIPTION

[0078] Tests were run to compare the performance of medicinal Vancomycin hydrochloride eye drop formulations in the dosage strengths 10, 25 and 50 mg / mL in respect of their ability to supress the following bacterial strains:

[0079] • S. Aureus;

[0080] • P Aeruginosa,;

[0081] • MRSA;

[0082] • S. Pneumoniae; and

[0083] • S. Epidermidis.

[0084] The test samples for each strength of Vancomycin hydrochloride, formulated with and without preservative, were as follows.

[0085] The tests involved determining the minimum inhibitory concentration (MIC) for each strain of bacteria. MIC means the lowest concentration of an anti-microbial drug that will inhibit the visible growth of a microorganism after overnight incubation.

[0086] Fortesting each formulation, a pure culture of each bacterial microorganism assessed was grown in Mueller-Hinton broth, and the culture was then standardized to a concentration of 1 x 106 cfu / mL. The antimicrobial agent was prepared at twelve two-fold diluted concentrations also in Mueller-Hinton Broth without cation (MHB), and each tube was then inoculated 1 :1 to a final concentration of 5 x 105 cfu / mL of microorganism.

[0087] In each case the test solution was incubated to the appropriate temperature for the microorganism, usually for not more than 24 hours. After incubation, the series of dilution tubes were observed for microbial growth. The last tube in the dilution series that did not demonstrate growth corresponded with the minimum inhibitory concentration (MIC) of the antimicrobial agent.

[0088] The tests were set up to establish a range of inhibitory concentrations that could be applied to all test formulations. The test method was performed on all microorganisms using the highest concentration solution (50 mg / mL) both with and without preservative, using MHB without cations and MHB with cations.

[0089] In each case an inoculum was prepared by diluting a suspension obtained from only four to five colonies of a pure nonselective nutritive agar medium sub-cultured at 24h, to avoid selecting out an atypical variant, by a loop to about 5 mL of appropriate diluent (e.g. Saline Solution (SS) or equivalent). The final concentration obtained was 1 - 2 x 108 cfu / mL. The viable count was confirmed by a pour plate method twice on Tryptone Soy Agar (TSA) after incubation for 48 hr at 37 ± 1 °C.

[0090] Standardisation of the inoculum was preferred for accurate and reproducible broth dilution susceptibility testing. Within 15 minutes before inoculation, the concentration was in each case adjusted to 1 x 106 cfu / mL in Muller-Hinton Broth (MHB).

[0091] The Vancomycin hydrochloride formulations to be tested were produced by double dilution steps. Three series of 12 tubes were labelled to equivalent to final concentrations of the nominal: 50%, 25.0%, 12.5%, 6.25%, 3.125%, 1.563%, 0.781%, 0.391 %, 0.195%, 0.098%, 0.049%, and 0.024%; 1 tube was labelled as “K-” equivalent to 0 mg / L.

[0092] Dilutions were prepared according to the following schema (by CLSI M100 Table 8A), and the volume was increased by multiples if necessary. No Vancomycin hydrochloride sample was added to tubes labelled “o” (antimicrobial-free growth control). Sample preparation was performed in the same way for all test formulations of Vancomycin solution with and without preservative (50 mg / mL, 25 mg / mL and 10 mg / mL ± preservative).

[0093]

[0094] Further, 1 mL of adjusted inoculum was added to each tube containing 1 ml_ of assay sample dilution series and also to antimicrobial-free growth control tubes. Each tube was mixed to obtain a homogenous dispersion of inoculum. Due to dilution, the final concentration of each sample tested in relation to the final concentration of inoculum was 1 :2 of the initial nominal amount. T ubes were capped and were then incubated at 37 ± 1°C for 24h within 15 minutes of inoculum. After incubation, all tubes were observed to assess turbidity. Turbidity was recorded as growth “+” and no growth was recorded as

[0095] To provide a purity check, and to verify the concentration of the inoculum suspension, a subculture on a nonselective agar plate for simultaneous incubation was prepared. For this a volume of 10 l_ of inoculum was dispersed in 10 mL of Saline Solution (SS) or equivalent. After mixing, 0.1 mL of this mixture was spread over the surface of suitable agar plate (e.g. TSA) and incubated at 37 ± 1°C for 24h. The presence of about 50 colonies confirmed an inoculum density of 5 x 105 cfu / mL. All colonies observed had the same morphology, which confirmed the purity of the culture. The growth observed in the growth control without antimicrobials was definitive.

[0096] The MIC in each case represents the lowest concentration of Vancomycin hydrochloride that completely inhibited the growth of microorganisms in the tubes. Comparison of growth in the tubes with growth in the growth control without antimicrobials was used to determine growth end points. The results of the method set-up for the formulations of Vancomycin hydrochloride 50 mg / mL with and without preservative on the three mediums are shown in the table below. The codes in the table refer to:

[0097] • A139: S. Aureus BAA-1764

[0098] • A138: S. Pneumoniae ATCC 49619

[0099] • A140: S. Epidermidis ATCC 700576

[0100] • B132: P. Aeurginosa. ATCC 27853

[0101] Further, routine test methodology was performed on all microorganisms under the same set-up conditions using the Vancomycin hydrochloride solutions with and without preservative at concentrations of 10 mg / mL, 25 mg / mL and 50 mg / mL using MHB without cations. MHB without cations was selected as no substantial changes in results were observed by adding Ca2+and Mg2+to MHB during the set-up experiments. The analyses were performed in duplicate.

[0102] The results of the tests performed for all the formulations of Vancomycin hydrochloride, with and without preservative on the one medium (MHB without cations), are shown in the table below. The codes in the table refer to:

[0103] • A139: S. Aureus BAA-1764

[0104] • A138: S .Pneumoniae ATCC 49619

[0105] • A140: S. Epidermidis ATCC 700576

[0106] • B132: P. Aeruginosa ATCC 27853

[0107] The results are shown graphically in Figures 1, 2 and 3 for P Aeruginosa, MRSA and S Aureus, where the Y-axis indicates the MIC and the X-axis indicates the Formulation tested. In the X-axis the term PF designates the preservative free formulation. While the tests were also run on S. Pneumoniae and S. Epidermidis, the results for these were not graphed as these strains were found to be completely sensitive.

[0108] As shown in Figure 1 , the 50 mg / mL formulation containing preservative was significantly better at suppressing P Aeruginosa bacteria than the 50 mg / mL preservative free formulation. This indicates that for the 50 mg / mL dosage, the preservative substantially assisted in supressing the bacteria. However, surprisingly, the preservative did not assist in suppressing P Aeruginosa bacteria for the 10 and 25 mg / mL formulations. This counterintuitively suggests that clinical efficacy can be achieved at lower Vancomycin hydrochloride concentrations without the need for any preservative.

[0109] Referring to Figures 2 and 3, surprisingly for all 25 and 50 mg / mL formulations the suppression of MRSA and S. Aureus bacteria was approximately the same regardless of whether the formulations included benzalkonium preservative. This was unexpected because one would predict the presence of benzalkonium preservative and / or a higher dose to give better suppression. This again counterintuitively indicates an ability to use lower doses and less Vancomycin hydrochloride (or of the free base or an alternative salt thereof) without losing therapeutic efficacy.

[0110] Referring to Figure 4, for comparison purposes tests substantially the same as those described above were again run for P Aeruginosa, but in this instance none of the test formulations tested contained the Tryptophan stabiliser. The test formulations were therefore as follows-

[0111] One reason for the Figure 4 tests was to assess whether Tryptophan was responsible for the preservative free 50 mg / mL formulation not working as well against bacteria as the 50 mg / mL preservative containing formulation. As illustrated in Figure 4, when Tryptophan was removed the 50 mg / mL formulations gave substantially the same level of suppression regardless of whether preservative was present. This indicates that for the higher dose Tryptophan has a negative effect on the ability of the formulation to suppress the bacteria. Optionally Formulations 10 and 11 are for delivery of 1 or 2 eye drops per eye each time they are delivered. Optionally each eye drop has a volume of 0.05 mL ±5%.

[0112] Optionally Formulations 10 is for delivery of 0.4 - 1.2 mg of Vancomycin hydrochloride (or an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt if substituted for the Vancomycin hydrochloride) each time Formulation 10 is administered.

[0113] Optionally Formulations 11 is for delivery of 1 .0 - 3.0 mg of Vancomycin hydrochloride (or an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt if substituted for the Vancomycin hydrochloride) each time Formulation 11 is administered.

[0114] Optionally Formulations 10 and 11 are for administration 1 , 2, 3 or 4 times per day.

[0115] While some embodiments of the invention have been described by way of example, it should be appreciated that modifications and improvements can be made without departing from the scope of the accompanying claims.

[0116] In terms of disclosure, this document envisages and hereby posits any feature mentioned herein in combination with a repeat of itself (eg two of the same) and / or any other feature or features mentioned herein, even if the combination is not claimed below.

Claims

CLAIMS1. The use of -• 10 mg / mL (±5%) or 25 mg / mL (±5%) Vancomycin hydrochloride or, in each case, an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt of Vancomycin;• Tryptophan;• Mannitol;• Methylcellulose; and• Water; in the manufacture of a medicament in the form of an eye drop formulation for use in treating an eye infection in a subject caused by one or more of S. Aureus, P Aeruginosa, MRSA, S. Pneumoniae, and S. Epidermidis.

2. A use according to claim 1 , wherein the formulation does not contain Benzalkonium chloride3. A use according to claim 1 or 2, wherein the Tryptophan is L-Tryptophan.

4. A use according to claim 1 , 2 or 3, comprising Vancomycin hydrochloride in the amount 10 mg / mL or 25 mg / mL.

5. A use according to any one of claims 1 to 4, wherein the formulation comprises: a) 25 mg / mL (±5%) Vancomycin hydrochloride; b) 0.77 mg / mL (±5%) L-Tryptophan; and c) Water.

6. A use according to any one of claims 1 to 4, wherein the formulation comprises: a) 10 mg / mL (±5%) Vancomycin hydrochloride; b) 0.31 mg / mL (±5%) L-Tryptophan; and c) Water.

7. A use according to any one of claims 1 to 4, wherein the formulation comprises: a) 25 mg / mL (±5%) Vancomycin hydrochloride; b) Tryptophan (eg in the amount 0.77 mg / mL ±5%); c) Mannitol (eg in the amount 3.0 mg / ml ±5%);d) Methylcellulose (eg in the amount 0.5 mg ±5%); and e) Water.

8. A use according to any one of claims 1 to 4, wherein the formulation comprises: a) 10 mg / mL (±5%) Vancomycin hydrochloride; b) Tryptophan (eg in the amount 0.31 mg / mL ±5%); c) Mannitol (eg in the amount 3.0 mg / mL ±5%); d) Methylcellulose (eg in the amount 0.5 mg / mL ±5%); and e) Water.

9. A use according to any one of the preceding claims, wherein the formulation is a solution.

10. A use according to any one of the preceding claims, wherein the formulation has a pH of 2.5 - 4.5.

11. A use according to any one of the preceding claims, wherein the formulation has a pH of 3.0 - 4.0.

12. A use according to any one of the preceding claims, wherein the formulation has a pH of 3.5 ±5%.

13. A use according to any one of the preceding claims, wherein the formulation comprises sufficient acid or base to bring it to the pH parameter of claim 10, 11 or 12.

14. A use according to claim 1 or 2, wherein the formulation does not contain any of:• Benzododecinium bromide;• Sodium perborate;• Polycatonic polymer;• Polyquaternium-1 ;• Polyquaternium-42;• Purite;• Sodium chlorite;• SofZia;• Sodium Perborate; and• OcuPure.

15. A use according to any one of the preceding claims, wherein the formulation is preservative free.

16. A method of treating an eye infection in a subject caused by one or more of S. Aureus, P Aeruginosa, MRSA, S. Pneumoniae, and S. Epidermidis, comprising administering to an eye of the subject a formulation manufactured in accordance with the use of any one of claims 1 to 15.

17. A method of treating a bacterial eye infection in a subject comprising administering an eyedrop formulation to an eye of the subject wherein the formulation comprises 10 mg / mL (±5%) to 25 mg / mL (±5%) Vancomycin hydrochloride or, in each case, an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt of Vancomycin, and wherein the eye is not exposed to benzalkonium chloride during the entire period that the eye is infected.

18. A method according to claim 17, wherein the formulation has been manufactured in accordance with the use of any one of claims 1 to 15.

19. A method according to claim 16, 17 or 18, wherein each time the formulation is administered it is administered as 1-2 eye drops per eye, each drop having a volume of 0.05 mL ±5%.

20. A method for treating a patient having an eye infection caused by one or more of Aureus, P Aeruginosa, MRSA, S. Pneumoniae, and S. Epidermidis, the method comprising administering 0.05 to 0.1 mL (±5%) of an aqueous formulation comprising 10 mg / mL (±5%) or 25 mg / mL (±5%) Vancomycin hydrochloride or, in each case, an equivalent amount of Vancomycin free base or an equivalent amount of an alternative salt of Vancomycin, and Tryptophan, wherein the composition does not comprise Benzalkonium chloride.

21. A method according to claim 20, wherein the formulation comprises mannitol and methylcellulose.

22. A method according to claim 20 or 21 , wherein the Tryptophan is L-Tryptophan.

23. A method according to claim 20, 21 or 22, where the formulation comprises 10 mg / mL (±5%) Vancomycin hydrochloride and 0.31 mg / mL (±5%) L-Tryptophan.

24. A method according to claim 20, 21 or 22, wherein the formulation comprises 25 mg / mL (±5%) Vancomycin hydrochloride and 0.77 mg / mL (±5%) L-Tryptophan.

25. A method according to any one of claims 16 to 24, wherein the formulation is administered 1 , 2, 3 or 4 times each day.

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