AU2013248191A1 - Veterinary compositions for treating mastitis - Google Patents

Abstract

Veterinary compositions for treating mastitis Abstract The present invention relates to a veterinary composition for the prophylaxis and treatment of mastitis in mammals. More particularly, the present invention relates to the treatment of 5 mastitis in cows. The formulations of the present invention comprise two parts which are generally administered to the animal as two separate formulations, The first part is a seal formulation comprising a gel base and a non-toxic heavy metal salt in the base. The second part of the formulation is the oil based product which may for instance comprise an antibiotic in an oil-based formulation. The oil-based formulation may however contain any pharmaceutically 10 active agent for the treatment or prophylaxis of disease in cattle.

Description

1 VE-ERJNARY COMPOSITIONS FOR TREATING MASTITIS The present invention relates to a veterinary composition for the prophylaxis and treatment of mastitis in mammals. More particularly, the present invention relates to the truatmient of mastitis in cows. It is well established that bacterial infection via the teats of a cow is the most common cause of mastitis, Various treatments are available in the prior art which attempt to prevent mastitis occurring or to treat the symptoms of mastitis. Thus, teat dip compositions are disclosed in US 5211961, which are used as antibacterial washes for cleaning the teats. Alternatively, EP 1104233 and EP 799047 discIose fihn-forming compositions which can be applied to the teat to provide a barrier to the entry of bacterial agents. Another approach employed involves the provision of a physical barrier in the teat canal in order to prevent the ingress of pathogens as described in GB 1441747. G13 2273441 discloses an antibacterial formulation and a seal fonnulation which are used in combination to form a plug and treat mastitis. A related patent, GB 2273443,. likewAise discloses the use of an antibacterial formulation and a seal formulation for the treatment of mastitis in cows. In GB 2273441, the seal formulation comprises a gel base and a non-toxic heavy metal salt in the base whereas in GB 2273443 the seal formuladon comprises a polyethylene gel, The antibiotic is provided separately in an aqueous formulation and GB 2273441 discloses that the aqueous formulations of antibiotic lead to rapid absorption in a very short time period. Surprisingly, we have now found that the co-administration of an oil-based product with a seal formulation containing a non-toxic heavy metal salt leads to an improvement in seal effectiveness. There are various types of oil such as mineral oil, silicone oil and vegetable oil and we have found that the use of a vegetable oil based antibiotic in combination with a seal formulation leads to an improvement in the seal effectiveness. The tests conducted in GB 2273441 indicated that an aqueous-based antibiotic formulation provided significant advantages relative to prior art formulations in the 2 treatment of dry cows. We have now found that, in fact, the use of oil-based formulations, and in particular vegetable oil-based formulations of antibiotic, leads to further improvements insofar as consumer health and animal welfare are concerned. An important property of an ideal teat seal is that the seal should be capable of remaining in situ for the duration of the dry cow period. The seal should also have sufficient integrity such that it is not caused to break or rupture within the udder. In addition, the seal formulation should be compatible with the co-administered formulation. Ti fornulations of the present invention satisfy these criteria and lead to improved performance of the seal and improved teat condition. The exact reason VOr the improved performance and teat condition of animals treated with formulations according to the present invention is not fully understood. Furthermore, the prior art unambiguously indicates that aqueous based antibiotic formulations are rapidly absorbed and provide significant advantages. Without wishing to be bound by theory, it is believed that the oil-based formulations of the present invention enhance the effectiveness of the seal formulation in situ and offer improved.± comipatiuiiy with thU s'ai the tnrei-at cInal relatve to aqueUs formulations. It is believed that the physical properties such as the density, and viscosities of the vegetable oils also are in some way connected with the improvement in performance. The formulations of the present invention comprise two parts which are generally administered to the animal as two separate formulations. The first part is a seal formulation comprising a gel base and a non-toxic heavy metal salt in the base. The second part of the formulatioti is the oil based product which may for instance comprise an antibiotic in an oil-based formulation. The oil-based formulation may however contain any pharmaceutically active agent for the treatment or prophylaxis of disease in cattle. According to one aspect of the present invention, there is provided a veterinary composition for intra-mamnmary use in non-human animals comprising an antibacterial fonnulation and a separate seal formulation, wherein the antibacterial formulation is an oil-based formulation and the seal formulation comprises a gel base 3 and a non-toxic heavy metal salt in the base in an amount ofat least 30% by weight of the gel base. In an embodiment of the present invention, the heavy metal is preferably bismuth, especially as the sub-nitrate saL Preferably, the heavy metal salt is present in an amount of from 40% to 80% by weight of the gel base and more preferably in the range of from 50% to 70% by weight. A particularly effective seal formulation contains about 65% by weight ie from 62 to 66% by weight of the heavy metal salt In another embodiment of the invention, the base is a gel based on aluminium stearate and more preferably the gel also includes a vehicle such as liquid paraffin. In another embodiment of the invention, the co administered oil based formulation is preferably based on a vegetable oil. In another embodiment of the invention, the cc administered oil based formulation is preeIrably based on a vegetable oil and contains an antibiotic. We aive found peanut oil and hydrogenated peanut oil to be particularly effective as the base for an antibacterial fonnulation which is to be used in conjunction with a seal formulation. In another embodiment of the present invention, the antibacterial agent is preferably a beta- lactam antibiotic such as a penicillin or cephalosporin. More especially, cloxacillin and more preferably cloxacillin benzathine. However, any antibiotic which has been approved for veterinary use may be employed. In another embodiment of the present invention, the veterinary composition of the present invention is provided as a unit dose. Typically, a unit dose would contain 600 mg of cloxacillin in the form of cloxacillin benzathinc. In an alternative aspect of the present invention, the antibacterial formulation and the seal formulation may be provided as a single formulation which may be administered to the teat canal of a non-human animal directly in one step. The relative proportions of the ingredients in such a formulation are identical to those in a formulation which is to be applied as two separate formulations.

4 In a further aspect of the present invention, there is provided the use of a veterinary composition comprising an antibacterial formulation and a scal formulation either separately or in a single formulation as defined above in the manufacture of a medicament for the treatment of prophylaxis or manmary disorders in non-human animals. Examples of specific seal formulations which may be used with the oil-based antibiotic formulations of the present invention are disclosed in GB 2273441 and GB 2273443 and those disclosures are specifically intended to be incorporated herein by reference. For the avoidance of doubt, suitable seal formulations and speci ic examples of seal formulations disclosed in those documents are suitable for use in the formulations of the present invention and are included within the scope of seal < formulations according to the present invention. The integrity of veterinary formulations according to the present invention was assessed by administration into the quarters of a dry cow. The cow was dosed with three different vegetable oil-based intra-mammary antibiotic formulations, each placed in a separate teat, Each of the three teats was then sealed with a bismuth-based teat seal enntnining 65% by weight bismuni sub-nitrate as described in fonnuiation 2A4 of GB 2273441. The fourth teat received'only the seal formulation having an identical seal fonnulation (ie containing 65% by weight bismuth sub-nitrate) but no antibiotic formulation. The teats were assessed by X-ray analysis and the radioopacity of the heavy metal salt provided clear pictures of the seal integrity and amount of seal within the desired area of the teat canal. The teats were X-rayed at days 1, 7, 14 and 21 to determine the area of opacity and hence the seal integrity. The results are summarised in Table I below.

5 Table I TEAT I TEAT 2 TEAT 3 TEAT 4 ANTIBIOTIC None Formulation A Formulation B Formulation C FORMULATION AVERAGED 1.0 1.1 1.7 1.6 AREA OF OPACITY Antibiotic formulation A contained peanut oil and hydrogenated peanut oil. Antibiotic formulations B and C contained peanut oil In each case, it was observed that co-administration 5 of the vegetable-oil-based antibiotic formulation in conjunction with the seal formulation lead to an increase in the amount of seal present at the base of the teat canal. Thus, despite an expectation that the ol-based antibiotic formulation might disperse the oil-based seal formulation it was in fact observed that the amount of seal present in the base of the teat increased. Thus, the formulations of the present invention offer advantages relative to prior art formulations- It is 10 important that the seal is present at the base of the teat and that it remains intact at the base of the teat in order to prevent the ingress of organisms into the udder which will lead to mastitis. The veterinary formulation of the present invention satisfied these requirements. Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a 15 stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps, Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the 20 prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this specIflIcation.

Claims (11)

1. A veterinary composition for intra-mammary use in non-human animals comprising an antibacterial formulation and a separate seal formulation, wherein the antibacterial formulation is an oir-based formulation and the seal formulation comprises a gel base and a non-toxic heavy 5 metal salt in the base in an amount of at least 30% by weight of the gel base.

2. A composition comprising an antibacterial formulation and a seal formulation may be provided as a single formulation which may be administered to the teat canal of a non-human animal directly in one step, wherein the antibacterial formulation is an oil-based formulation and the seal formulation comprises a gel base and a non-toxic heavy metal salt in the base in an 10 amount of at least 30% by weight of the gel base.

3. A composition as claimed in claim 1 or 2, wherein the heavy metal is bismuth.

4. A composition as claimed in claim 3, wherein the heavy metal salt is bismuth sub-nitrate,

5. A composition as claimed in claim 1, 2,3, or 4, wherein the heavy metal salt is 15 present in an amount of from 40% to 80% by weight of the gel base.

6. A composition as claimed in any preceding claim, wherein the co administered oil based formulation is based on a vegetable oil.

7. A composition as claimed in any preceding claim, wherein the base is a gel based on aluminium stearate. 20

8. A composition as claimed in any preceding claim, wherein the vegetable oil base for an antibacterial formulation is peanut oil and/or hydrogenated peanut oil.

9. A composition as claimed in any preceding claim, wherein the antibacterial agent is a bela-lactam antibiotic.

10, A composition as claimed in claim 9, wherein the antibacterial agent is cloxacillin. 25

11. Use of a veterinary composition comprising an antibacterial formulation and a seal formulation either separately or in a single formulation as defined above in any of claims I to 8 in the manufacture of a medicament for the treatment of prophylaxis or mammary disorders in non human animals-