IE85169B1 - A method and device for the sequential delivery of two components into the teat canal of a non-human animal - Google Patents

Abstract

ABSTRACT The invention relates to a method and device for treating or preventing or suppressing a disease or condition in a non—human animal. The method comprises the steps of providing a single delivery device containing two components for sequential delivery from the delivery device. A first component is delivered from the single delivery device into a teat canal of a non—human animal and subsequently the second component is delivered from the single delivery device into the teat canal. The components are delivered without substantial mixing of the components.

Description

the epithelium of the streak canal. The use of two injectors also increases the cost of treatment and creates additional non—degradable waste. lhere is a need for an improved method and device for preventing intrammary disorders which will overcome at least some ofthese problems.

Statements of Invention According to the invention there is provided an injector device for delivery of components into the teat canal of a non-human animal comprising: a barrel for containing a first component; an outlet nozzle configured for insertion into a teat canal at one end of the barrel; an internal receptacle within the barrel for containing a second component to be injected into the teat canal; a valve for separating the first component from the second component; an activator for releasing the valve to allow the second component to be released from the internal receptacle; and a delivery means for delivery of a tirst component from the barrel. and, an engagement of the valve with the activator to release the valve, sequential delivery of a second component from the internal receptacle through the outlet nozzle. ln one embodiment the barrier comprises one or more passageways. ln another embodiment the one or more passageways are opened when the barrier is released for delivery ofthe second component through said one or more palssageways. ln another embodiment the activator comprises at least one projecting member.

In a further embodiment the activator is located in the barrel.

In one embodiment the activator is located adjacent to the outlet no7zle.

In another embodiment the activator comprises one or more passageways. ln a further embodiment the activator is configured for engagement with the internal receptacle to provide a direct passageway for delivery of the second component from the internal receptacle into the outlet nozzle.

In one embodiment the delivery means comprises a plunger for the barrel.

In a further embodiment the internal receptacle comprises an inner barrel located within an outer barrel defined by the barrel of the injector.

In one embodiment the inner barrel is a close tit within the outer barrel. ln another embodiment the delivery means comprises the inner barrel.

In a further embodiment the inner barrel defines a plunger for the outer barrel. ln one embodiment the delivery means comprises a plunger for the inner barrel.

In another embodiment the inner barrel comprises engagement means for engagement with the outer barrel on assembly.

In a further embodiment the engagement means comprises an external seal.

In one embodiment the outer barrel comprises engagement means for engagement with the inner barrel.

In another embodiment the outer barrel comprises a locking ring for engagement with the inner barrel.

In a further embodiment the inner barrel comprises engagement means for engagement with the plunger.

In one embodiment the inner barrel comprises a locking ring for engagement with the plunger.

In another embodiment the barrel contains a first component.

In a further embodiment the first component comprises an antimicrobial formulation.

In one embodiment the internal receptacle contains a second component.

In another embodiment the second component comprises a seal formulation.

In a further embodiment a first component is delivered from the barrel and a second component is subsequently delivered from the internal receptacle without substantial mixing ofthe components.

In one embodiment the seal formulation comprises a non—toxic heavy metal salt.

In another embodiment the seal formulation comprises greater than 40% by weight of the heavy metal salt.

In a further embodiment the seal formulation comprises between 50% and 75% by weight ofthe heavy metal salt.

In one embodiment the seal formulation comprises approximately 65% by weight of the heavy metal salt.

In another embodiment the heavy metal is bismuth.

In a further embodiment the salt is a sub—nitrate salt.

In one embodiment the seal formulation comprises a gel base.

In another embodiment the gel base is a gel based on aluminium stearate.

In a further embodiment the gel base includes liquid paraffin as a vehicle.

In one embodiment the first component comprises an antimicrobial.

In another embodiment the antimicrobial is selected from any one or more of betalactam antibiotics, polymyxins, glyeopeptides. aminoglycosides, lineosamides, macrolides, pleuromutilins. “fenieols” such as chloramphenicol and florfenicol, tetracylcines. sulphonamides and potentiated sulphonamides such as mixtures of trimethoprim and one or more sulphonamide, quinolones, lluoroquinolones, ionophores. courmarins such as red C: novobiocin, natural or and synthetic pcptides, aminoglycosides, antimicrobial peptides or antimicrobials. Iantibiotics, or other products of bacteria and other microorganisms.

In a further embodiment the betalactum is selected from any one or more of penicillin, modified penicillin such as cloxacillin, amoxycillin, ampicillin, cephalosporins or beta Iactam antibiotics potentiated by beta lactamase inhibitors such as clavulanic acid.

In one embodiment the aminogylcosidc is selected from any one or more of streptomycin, dihydrostrcptomycin, neomycin, gentamycin, framycetin, aparamycin or kanamycin.

In another embodiment the antimicrobial is selected from any one or more ofrnacrolide, Iincosamide or pleuromutilin, erythromycin, spiramycin. tylosin, spiramycin. tilimicosin, lincomycin. spectinomysin, pirlimycin or tiamulin.

In a further embodiment the antimicrobial is selected from any one or more ofpotentiated sulphonamide mixtures, trimethoprim plus sulphadiazine, sulphadimidine. sulphadoxine, sulphadimcthoxinc or other sulphonamide, oxytetracycline, minocycline or doxyclycline.

Iluoroquinolonesr enrofloxacin, ciprolloxacin, norfloxacin, danofloxacin. ditloxacin or marbotloxacin.

In one embodiment the first component comprises an anti-inflammatory.

In another embodiment the anti-inflammatory is selected from any one or more of steroids such as prednisolone, betamethazone, dexamethazone, phenylbutazone, or non- stcroids such as llunixin, ketoprofen, carprofen, Vedaprofen, meloxicam. tepoxalin, eltenac, nimesulide or tolfenamic acid.

Briefdescription of Drawings The invention will be more clearly understood from the following description thcrcol‘ given by way ofexample only with reference to the accompanying drawings. in which: — Fig. l is a schematic cross sectional view of an injector device: Fig. 2 is a cross sectional view of an internal barrel ofthe device of Fig. l; Fig. 3 is a cross sectional view of the internal barrel of Fig. 2 with a seal component in place; Fig. 4 is a cross sectional view of the internal barrel of Fig. 3 with a plunger inserted: Fig. 5 is a cross sectional view of an external barrel ofthe device of Figs. 1 to 4: Fig. 6 is a cross sectional view of the external barrel of Fig. 5 with an antimicrobial component in place; Fig. 7 is a cross sectional View of the assembled injector device; Figs. 8(a) to 8(c) are cross sectional views of the injector device of Figs. l to 7. in U86; Fig. 9 is a cross sectional view of another injector; Fig. 9(a) is an enlarged View of portion of the injector in Fig. 9; Figs. 10 to 12 are cross sectional views of an injector device according to the invention in different configurations of use: Fig. 13 is a top plan view ofthe device of Fig. 10; Figs. 14 (a) to 14 (c) are cross sectional views of a further injector device according to the invention in different configurations of use; Fig. 15 is an exploded broken out view of components of the injector ofFig. 14; Figs. 16 (a) is a detailed cross sectional view of a portion of the injector of Fig. 14, and Figs. 16 (b) and 16 (c) are detailed perspective views ofa portion of the device in the configurations of1~’ig. 14 (b) and (c) respectively; Fig. 17 is a schematic cross sectional view of another injector device; Fig. 18 (a) to 18 (d) are cross sectional views ofthe device of Fig. 17, in use; Fig. 19 is a schematic cross sectional View of another injector device; and Figs, 20 (a) to 20 (c) are cross sectional views of the injector device of Fig. 19, in USB.

Detailed Description The invention provides an injector device that allows for the sequential delivery of two incompatible components such as an antimicrobial formulation and a seal formulation into the teat canal of a non—human animal. The seal formulation and antimicrobial formulation are contained separately within a single injector device. The enables the product to be stored without affecting the stability of either component. The device also provides for the delivery of the antimicrobial formulation ahead of the seal formulation which effectively forms a physical barrier in the teat canal preventing any further entry into the teat canal. The seal formulation also prevents the possibility of the antimicrobial phase leaking or being expressed from the teat by gravitational or hydrostatic forces.

The seal formulation may comprise a viscous oil-based cerate containing a high proportion of a heavy metal salt, bismuth subnitrate. The product Teat Seal (trade mark of Cross Vetpharm Group) is described in detail in W098/26759 and comprises a non- toxic heavy metal salt in a gel base. The base is a gel based on aluminium stearate. The gel preferably includes a vehicle such as liquid paraffin. The gel may also comprise a polyethylene gel. The gel may be based on low density polyethylene or on high density polyethylene. Preferably, the heavy metal salt is present in an amount of greater than 4t %, preferably between 50% and 75% by weight, most preferably approximately 65% by weight.

The seal formulation prevents infection entering the udder via the teat or streak canal through a combination of its viscosity. density and adhesiveness.

The antimicrobial or anti—inflammatory formulation may be selected from any one or more of a wide variety of compounds that are known to be effective for the treatment. prevention and elimination of mastitis and mastitis-causing organisms, including inter alia gram positive and gram negative bacteria. yeasts, fungi and rickcttsias. The antimicrobial or anti-inflammatory materials may include inter alia beta lactam antibiotics such as penicillins and cephalosporins. beta lactam antibiotics potentiated by beta lactamasc inhibitors such as clavulanie acid. polymyxins, glycopeptides. aminogylcosides. lincosamides, “fenicols“ such as macrolides, pleuromutilins, chloramphenicol and florfenicol, tetracyclincs, sulphonamides and potentiated sulphonamides such as mixtures of trimcthoprim and one or more sulphonamide, quinolones and fluoroquinolones, ionophores, coumarins such as novobiocin. natural or synthetic peptides, lantibiotics, and other antimicrobial products of bacteria and other inicro-organisms.

Other antimicrobials may be selected from any one or more of macrolide. lincosamide or pleuromutilin. crythromycin, spirarnycin. tylosin, spiramycin. tilmicosin. lincomycin. speetinomysin, pirlimycin, tiamulin, potentiated sulphonamide mixtures. trimethoprim plus sulphadiazine. sulphadimidine, sulphadoxine, sulphadimethoxine or other sulphonamicle. oxytetracycline, minocycline or doxyelycline, lluoroquinolones. enrotloxacin, ciproiloxacin, norfloxacin, danofloxacin, dilloxacin or marbolloxacin.

The second component may be selected from any one or more of anti—inllammatory compounds. steroids such as prednisolene, betamethazone, dexamethasone, phenylbutazone. or non-steroids such as flunixin, ketoprofen, earprofen. vedaprofen, meloxicam. tepoxalin, eltenac, nimcsulide or tolfenamic acid.

Other antimicrobial or anti-inflammatory compounds used in the treatment of intramammary infections in non-human animals may also be used.

These antimicrobial or anti-inflammatory materials may be formulated either singularly or in combinations of two or more compounds as liquids, cerates, solutions. suspensions emulsions or llowable powders in water, oil (of animal, vegetable, mineral or other origin) or other organic vehicles. Other excipients such as solubilising, suspending or emulsifying agents, viscosity modifiers. surfactants. encapsulating agents and other means to adjust the rate at which the compound(s) is released from the formulation. buffers and such agents to maintain the pH of the formulation, anti-inflammatory agents such as various steroidal and non—steroidal compounds commonly used for this purpose, and various preservative agents commonly used in pharmaceutical preparations.

Referring to the drawings and initially to Figs. 1 to 8 there is illustrated an injector device 1. The injector device 1 in this case comprises an inner barrel 2 and an outer barrel 3.

The outer barrel 3 has a nozzle 4. The inner barrel 2 contains a first component comprising a seal 9. The barrel 2 has a barrier or membrane 5 at its distal end. A plunger 6 is inserted into the proximal end of the inner barrel 2 above the seal component 9. An antimicrobial or anti-inflammatory component 10 is contained within the outer barrel 3 below the inner barrel 2. In use. the nozzle 4 is inserted into a teat canal 20 of a non- human animal such as a cow. The inner barrel 2 is pushed through the outer barrel 3 by the plunger 6 to expel the antimicrobial or anti—inflammatory component 10 (Fig. 8(a)).

When the antimicrobial or anti—inflammatory component 10 has been expelled (Fig. 8(b)) the plunger 6 on the inner barrel 2 is further depressed to expel the seal 9 from the inner barrel 2. The pressure of the plunger 6 may be sufficient to release or rupture the barrier/membrane 5 on the inner barrel 2 allowing the seal 9 to be expelled from the in_jector device through the nozzle 4 and into the teat canal (Fig. 8(c)). Rupturing means such as teeth 30 situated within the outer barrel 3 adjacent to the outlet nozzle 4, may be used to release or rupture or open the barrier/membrane 5.

Referring to Figs. 9 and 9 (a) there is illustrated another injector which is similar to the injector of Figs. 1 to 8 and like parts are assigned the same reference numerals. The injector device I comprises an inner barrel 2 and an outer barrel 3. The outer barrel 3 has a nozzle 4. In this case the barrier is released by an activator defined by a number of spikes 50 projecting upwardly to different lengths. The membrane/barrier has a portion 51 which is knocked-out by the spikes 50 to allow ejection of the seal component. The distal end of the inner barrel 2 has a seal or frill 53 which seals with the inner wall of the outer barrel 3.

Referring to Figs. 10 to l3 there is illustrated an injector device according to the invention in which like parts to those of Figs. 1 to 9 are assigned the same reference numerals. The injector device 1 comprises an inner barrel 2 and an outer barrel 3. The outer barrel 3 has a nozzle 4. In this case the barrier comprises a valve 60 at the distal end of the inner barrel 2. An activator 61 projects upwardly from the lower wall of the outer barrel. In use, when the inner barrel 2 is in the configuration of Fig. 11 the valve 60 is lifted by engagement with the activator 61 and allows the seal component 9 in the inner barrel 2 to pass through the injector nozzle 4.

When the plunger 6 is pushed down. the inner barrel 2 also travels down through the outer barrel 3. The outside of the inner barrel 2 is a close fit in the outer barrel 3 so that the inner barrel 2 itself acts as a delivery device or plunger for delivery of the first component from the outer barrel 3 through the nozzle 4.

Referring to Figs. 14 to 16 there is illustrated another injector device of the invention in which like parts to those of Figs. 1 to 13 are assigned the same reference numerals. The injector device comprises an inner barrel 2 and an outer barrel 3. The outer barrel 3 has a nozzle 4. The inner barrel 2 contains a seal component 9. A plunger 6 is inserted into proximal end of the inner barrel 2 above the seal component 9. Antimicrobial 10 is contained within the outer barrel 3. In use, the nozzle 4 is inserted into a teat canal 20.

The inner barrel 2 comprises a distal end 74 having an outlet 75 and the barrier comprises a valve 70 which is received in the outlet 75. The valve 70 is normally closed (Figs. l4(a). (b)) during delivery of the first component from the outer barrel 3. An activator 71 projects upwardly from the lower wall of the outer barrel 3. In use, when all of the first component has been delivered and the inner barrel 2 is in the configuration of Fig. l4(c) the valve 70 is released by engagement with the activator 71 and the seal component 9 in the inner barrel 2 is allowed to pass through side passageways 76 in valve through the outlet 75 and into the injector nozzle 4.

The inner wall of the inner barrel 2 is formed for engagement with the plunger 6 and comprises a locking ring 173 between the proximal and distal ends thereof. The inner barrel 2 comprises a distal portion 178 and a proximal portion 179, the distal portion 178 to 'Jw having an integral diameter less than the internal diameter of the proximal portion 179.

The plunger 6 comprises a seal 77 which passes over the locking ring 173 of the inner barrel on assembly and the plunger 6 is thus sealingly engaged with the inner barrel 2.

The inner barrel 2 further comprises an external seal 72 for engagement with the internal wall ol‘ outer barrel 3. The external seal 72 may for example comprise an integrally formed seal or an o-ring housed in a recess 172 in the external side wall of the inner barrel 2. The external seal 72 is located near the distal end 74 of the inner barrel.

The internal wall of the outer barrel 3 is fomied for engagement with the inner barrel 2 and comprises a locking ring 73 between the proximal and distal ends thereof for engagement with the external seal 72 of the inner barrel 2. The outer barrel 3 comprises a distal portion 78 and a proximal portion 79. The distal portion 78 having an internal diameter less than the internal diameter of the proximal portion 79. The external seal 72 passes over locking ring 73 of the outer barrel 3 on assembly and sealingly engages the outer barrel. The antimicrobial or anti-inflammatory formulation l0 is thus prevented from passing between the barrels as the plunger 6 is depressed.

The valve 70 comprises a plurality of channels 76 which are exposed when the valve 70 is released to allow the seal component to pass out through the valve. Thus upon releasing ofthe valve the channels 76 which detine a passageway for the seal component are opened.

The activator 7l defines a substantially cylindrical form defining a passageway and corresponds in form to the outlet 75 enabling it to be received in a portion ol‘ the outlet.

The activator 7l is a close fit with the outlet 75. ln use the inner barrel 2 is pushed through the outer barrel 3 by the plunger 6 to expel the antimicrobial ll) (Fig. 14(a)). The outside of the inner barrel 2 has the geometry of the plunger 6 so that the inner barrel 2 itself acts as a plunger. When the antimicrobial 10 has been expelled (Fig. 14(b)) the plunger 6 on the inner barrel 2 is further depressed to expel the seal 0 from the inner barrel 2. The valve 70 is released by engagement of the inner barrel with the activator 71 and the seal component 9 in the inner barrel 2 is allowed to pass through the valve passageways into the injector nozzle 4 and is expelled into the teat canal (Fig. l4(e)).

Referring to Figs. 14 to 16, and in particular Figs. 16 (b) and (c) the operation of the valve is described in more details.

When closed the valve 70 which is a close fit with the outlet 75 rests in the outlet and prevents any mixing of the components in the outer and inner barrels (Fig. l4(b) and l6(b)).

When the activator 71 is received in the outlet 75 (Figs. 14(c) and 16(c)) the valve is released and the passageways 76 in the valve are opened to enable the seal component to pass into the valve passageways 76 through the passageway defined by the activator 71 and into the injector nozzle 4.

The engagement of the activator 71 with the outlet of the inner barrel 2 provides for alignment of the respective passageways 76 of the valve and the activator before the valve is released and the seal component is allowed to pass from the inner barrel. The respective passageways 76 of the valve and activator provide a closed and isolated pathway for the seal component to pass from the inner barrel 2 directly into the injector no7.7.le 4.

One advantage of a valve type barrier of this embodiment is that there is not risk of any part olthc barrier becoming mobile. The barrier is retained with the injector.

Referring to Figs. 17 to 18 there is illustrated an injector device 81 which is similar to the injector of Figs. 1 to 9 and like parts are assigned the same reference numerals. The injector device 81 comprises a barrel 3. an outlet nozzle 4 and a plunger 6. Two incompatible components 9 and l() are placed within the barrel 3 of the injector device 81. The two components such as an antimicrobial 10 and a seal 9 are separated from one another by a barrier/membrane. The antimicrobial 10 is placed in the barrel 3 and a seal 9 is placed in a receptacle 86 such as a bag which is defined by an outer membrane 87 which provides the barrier.

The receptacle 86 may comprise a capsule into which the seal is filled on manufacture.

The capsule may then be readily dropped into the barrel 3 of the injector before a plunger is inserted.

When the nozzle 4 of the device 81 is inserted into a teat canal 16 a user depresses the plunger 6 to effect delivery of the antimicrobial 10 from the injector device into the teat canal (Figs. l7(a)). After the antimicrobial 10 is expelled from the injector device further pressure applied to the plunger results in puncturing or bursting of the receptacle 86 allowing egress of the seal 9 which is delivered into the teat canal (Fig. l7(b)). Fig. l7(d) shows the position of a seal formulation 9 and antimicrobial formulation 8 on delivery into the teat of a non—human animal.

The injector device may comprise rupturing means such as sharp teeth 88 at the distal end of the barrel 3 to assist in puncturing or bursting the receptacle 86.

It will be appreciated that for ease of manufacture and use, the receptacle 86 may be attached to the plunger 6. In this case the receptacle is unable to come into contact with the rupturing device until substantially all of the first component has been expelled from the device.

When delivering a seal 9 and antimicrobial or anti-inflammatory fomiulation 10 into the teat canal of a non—human animal the injector device is typically positioned vertically below the teat with the delivery nozzle uppermost. The seal formulation 9 has a much higher specific gravity than the antimicrobial or anti-inflammatory formulation 10 and therefore the receptacle containing the seal formulation remains at the lower end of the barrel 3 containing the antimicrobial or anti-inflammatory formulation during the delivery of the antimicrobial or anti-inflammatory formulation into the teat. In this case the receptacle comes into contact with the rupturing device only when substantially all of the antimicrobial or anti-inflammatory formulation has been delivered into the teat.

Referring to Figs. 19 and 20 there is illustrated another injector device 90. The injector device 90 comprises an inner barrel 92 and an outer barrel 93. The outer barrel 93 has a nozzle 94. The inner barrel 92 comprises a breakable/burstable barrier or membrane at its distal end and a plunger 98 at its proximal end. Antimicrobial 10 is contained within the outer barrel 93. In use, the nozzle 94 is inserted into a teat canal 16. The inner barrel 92 is pushed through the outer barrel 93 to expel the antimicrobial (Fig. 20(b)). This procedure may be facilitated by a flange 97 around the proximal end of the inner barrel 92 and a flange 99 around the proximal end of the outer barrel 93. When the antimicrobial 10 has been expelled (Fig. 20(e)) the plunger 98 on the inner barrel 92 is depressed to expel the seal 9 from the inner barrel 91. The pressure of the plunger 98 is sufficient to burst or rupture the barrier/membrane 96 on the inner barrel 92 allowing the seal 9 to be expelled from the injector device through the nozzle 94 and into the teat canal (Fig. 20(0)). Alternatively rupturing means such as sharp teeth situated within the outer barrel 93 at its aperture into the nozzle, ruptures the barrier/membrane 96.

A seal 96 may be provided at the front end of the inner injector barrel 92 to provide a positive seal. The inner injector may be moulded with a weak burstable barrier/membrane 95 across the outlet aperture.

It will be appreciated that the seal portion of the formulation may be manufactured in one facility and subsequently combined with the anti—baeterial portion of the formulation at a later stage. in the same or another facility.

The invention is not limited to the embodiments hereinbefore described which may be varied in detail.

Qafirng . An injector device for delivery ofcomponents into the teat canal ofa non—human animal cornprising:- a barrel for containing a first component; an outlet nozzle configured for insertion into a teat canal at one end of the barrel: an internal receptacle within the barrel for containing a second component to be injected into the teat canal: a valve for separating the first component from the second component; an activator for opening the valve to allow the second component to be released from the internal receptacle; and a delivery means for delivery ofa first component from the barrel, and, an engagement of the valve with the activator to open the valve. sequential delivery of a second component from the internal receptacle through the outlet nozzle. . /\n injector device as claimed in claim I wherein the valve comprises one or more passageways.

Claims (1)

1. CLAIMS An injector device as claimed in claim 2 wherein the one or more passageways are opened when the valve is released for delivery of the second component through said one or more passageways. An injector device as claimed in any of claims 1 to 3 wherein the activator comprises at least one projecting member. /\n injector device as claimed in any of claims 1 to 4 wherein the activator is located in the barrel. An injector device as claimed in any of claims 1 to 5 wherein the activator is located adjacent to the outlet nozzle. An injector device as claimed in any of claims 1 to 6 wherein the activator comprises one or more passageways. An injector device as claimed in claims 1 to 7 wherein the activator is configured for engagement with the internal receptacle to provide a direct passageway for delivery of the second component from the internal receptacle into the outlet nozzle. An injector device as claimed in any of claims l to 8 wherein the delivery means comprises a plunger for the barrel. An injector device as claimed in any of claims 1 to 9 wherein the internal receptacle comprises an inner barrel located within an outer barrel of the injector. An injector device as claimed in claim 10 wherein the inner barrel is a close fit within the outer barrel. An injector device as claimed in any of claims 10 or 11 wherein the delivery means comprises the inner barrel. An injector device as claimed in claims 10 to 12 wherein the inner barrel defines a plunger for the outer barrel. An injector device as claimed in any of claims 10 to 13 wherein the delivery means comprises a plunger for the inner barrel. An injector device as claimed in claims 10 to 14 wherein the inner barrel comprises engagement means for engagement with out outer barrel on assembly. An injector device as claimed in claim 15 wherein the engagement means comprises an external seal. An injector device as claimed in claim 15 or 16 wherein the outer barrel comprises engagement means for engagement with the inner barrel. An injector device as claimed in claim 17 wherein the outer barrel comprises a locking ring for engagement with the inner barrel. An injector as claimed in any of claims 10 to 18 wherein the inner barrel com rises en a ement means for en a ement with the lun er. P 8 g g g P E An injector device as claimed in claim 21 wherein the inner barrel comprises a locking ring for engagement with the plunger. 21 An injector device as claimed in any of claims 1 to 20 wherein the barrel contains a first component. An injector device as claimed in claim 21 wherein the first component comprises an antimicrobial formulation. An injector device as claimed in any of claims 1 to 22 wherein the internal receptacle contains a second component. An injector device as claimed in claim 23 the second component comprises a seal formulation. A device as claimed in claim 24 wherein the seal formulation comprises a non- toxic heavy metal salt. A device as claimed in claim 25 wherein the seal formulation comprises greater than 40% by weight of the heavy metal salt. A device as claimed in claim 25 or 26 wherein the seal formulation comprises between 50% and 75% by weight of the heavy metal salt. A device as claimed in any of claims 25 to 27 wherein the seal formulation comprises approximately 65% by weight of the heavy metal salt. A device as claimed in any of claims 25 to 28 wherein the heavy metal is bismuth. A device as claimed in any of claims 25 to 29 wherein the salt is a sub—nitrate salt. A device as claimed in any of claims 25 to 30 wherein the seal formulation comprises a gel base. A device as claimed in claim 3] wherein the base is a gel based on aluminium stearate. A device as claimed in claim 3] or 32 wherein the gel base includes liquid paraffin as a vehicle. A device as claimed in any of claims 22 to 33 wherein the antimicrobial is selected from any one or more of betalactam antibiotics, polymyxins. glyeopeptides, aminoglycosides. lincosamides, macrolides, pleuromutilins. "fenieols" such as chloramphenicol and florfenicol, tetracylcines, sulphonamides and potentiated sulphonamides such as mixtures of trimethorpin and one or more sulphonamide, quinolones and lluorquinolones. ionophores, courmarins such as novohiocin. natural or synthetic peptides, aniinoglycosides, antimicrobial peptides or antimicrobials, lantibioties, or other products of bacteria and other micro- organisms. A device as claimed in claim 34 wherein the betalaetam is selected from any one or more of penicillin. modified penicillin such as cloxacillin, amoxicillin. ampicillin. cephalosporins or beta lactam antibiotics potentiated by beta lactamase inhibitors such as clavulanic acid. A device as claimed in claim 34 wherein the aminoglycoside is selected from any one or more of streptomycin, dihydrostreptomycin, neomycin, gentamyein. framycetin, aparamycin or kanamycin. A device as claimed in any of claims 22 to 33 wherein the antimicrobial is selected from any one or more of macrolide, lincosamide or pleuromutilin. erythromycin, spiramycin. tylosin. tilmicosin, spiramycin, lincomyein, spectinomycin, pirlimycin or tiamulin. An injector device as claimed in any of claims 1 to 37 wherein a first component is delivered from the barrel and a second component is subsequently delivered from the internal without substantial mixing ofthc components. An injector device substantially hereinbefore described with reference to