Bolus dosage form

Abstract

The disclosure provides a bolus configured for administration to an animal, wherein said bolus is configured to release a substance to the animal over a period of time. The bolus including (i) a core including at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier; (ii) a densifier; and (iii) a casing that encapsulates or substantially encapsulates the core, wherein the casing includes a closed region (i.e. a region that is closed during manufacture to encapsulate the core in the casing); wherein the core is separated from the closed region and the densifier is between the core and the closed region; and wherein the bolus is formulated to remain in the rumen following administration. Also provided are methods of using a bolus of the disclosure and methods of manufacturing a bolus of the disclosure.

Description

[0001] Bolus dosage form

[0002] This application claims priority to New Zealand provisional application NZ 810650 (filed on 1 May 2024), the entire contents of which are incorporated by reference.

[0003] Field of the disclosure

[0004] The present disclosure relates to improvements in devices and methods for delivery of substances to animals, and in particular to devices and methods for administering at least one substance to the rumen of a ruminant animal, and methods of manufacturing of the devices.

[0005] Background of the disclosure

[0006] In farming it is often necessary to deliver substances to animals. This can be for various purposes, including but not limited to treatment or prevention of disease and to increase animal production.

[0007] There are various devices (eg dosage forms) and methods to deliver substances such as medicaments to animals. Some substances are for administration to the rumen of ruminant animals. This poses specific challenges in drug delivery as the device needs to be both delivered to the rumen and, often, retained in the rumen to deliver and, often, delivery consistently over time the substance to the rumen. Retention of the device in the rumen can increase efficacy (ie by allowing for longer term efficacy) and reduce the side effects of dosage forms for administration of a substance to the rumen (ie by allowing lower consistent dosing or by preventing release of the substance to the other stomachs in a ruminant animal).

[0008] The problem of retention of devices in the rumen is increased where a dosage form is formulated for sustained release or otherwise needs to reside in the rumen for a long duration. A sustained release may be particularly desired wherein a low dosage of active substance for an extended period may provide best efficacy of treatment.

[0009] There is a need for improved devices or dosage forms for delivering substances to the rumen. Preferably, these devices or dosage forms are retained in the rumen of the animal at least until the majority of the substance is released from the device or dosage form. Reference to any prior art in the specification is not an acknowledgment or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be understood, regarded as relevant, and / or combined with other pieces of prior art by a skilled person in the art.

[0010] Summary of the disclosure

[0011] In one aspect, the present disclosure provides a bolus including: a core including at least one active ingredient and at least one carrier; a densifier; a casing that encapsulates or substantially encapsulates the core; wherein the casing includes a closed region (ie a region that is closed during manufacture to encapsulate the core in the casing); wherein the core is separated from the closed region and the densifier is between the core and the closed region; and wherein the bolus is formulated to remain in the rumen following administration.

[0012] Optionally, the core does not contact the closed region. Optionally, the densifier is between the closed region and the core. Preferably, the densifier is in direct contact with the core and the closed region, for example, between the core and the closed region. In some embodiments, there is direct contact between a part, or all, of the closed region and the densifier. Indirect contact is also contemplated.

[0013] Optionally, the densifier or densifier matrix has a specific position in the bolus, that is, in contact with the closed region and between the closed region and the core. In some embodiments, the closed region is at a first side or end of the bolus casing and the densifier or densifier matrix is also at the first side or end of the bolus within the casing. In this embodiment, the side or end of the densifier opposite the first side (ie the opposing side) is in contact with a first side or end of the core. Further, the opposing side or end of the core is in contact with the opposing side or end of the casing. Preferably, the closing region, densifier and densifier matrix are positioned at an end of the bolus. Preferably, the densifier is fixed in its location.

[0014] Alternatively, the one or more densifiers are fixed in location. Preferably, the densifier remains in location when tested in vitro with the densifier oriented at the top of the bolus (ie the opposite of the orientation in a rumen where the densifier will be at the bottom other than when moved by ruminal forces). In embodiments, where the densifier is fixed in its location, the densifier may be at either end of the elongated shape of the bolus, that is, in contact with the closed region or not in contact with the closed region. In preferred embodiments, the densifier is at one of the ends of the bolus. Alternatively, the densifier may be along the length of the bolus.

[0015] The densifier is either directly in contact with the casing or indirectly in contact with the casing. Where the contact is indirect, there is a barrier layer between the densifier and casing. A barrier layer may be used to assist with adhesion with the casing or spacing component or to prevent reactivity.

[0016] In some embodiments, the densifier is a densifier matrix comprising densifier and at least one veterinary acceptable excipient. Where the specification refers to a “densifier” a “densifier matrix” is a suitable alternative unless otherwise specified. Where there is a “densifier matrix” containing a densifier and an excipient. The densifier portion can be any of the materials that can comprise a non-matrix densifier. In some embodiments, the excipient is a matrix material such as a binder. Optionally, the densifier matrix includes a matrix material more hydrophobic than the at least one carrier. Optionally, the densifier matrix as a whole is more hydrophobic than the core or the densifier matrix excipients as a whole are more hydrophobic than the core excipients as a whole (ie carrier and any other excipient included). Optionally, the surface of the densifier matrix in contact with the core is more hydrophobic than the core. Optionally, the densifier matrix includes a wax (ie the excipient is a wax). Optionally, the densifier matrix includes a matrix material selected from castor wax, paraffin wax, stearic acid, microcrystalline wax, beeswax, stearyl alcohol, white wax, yellow wax, cetyl alcohol, cetyl esters wax, carnauba wax, ethyl vinyl acetate (EVA), and combinations thereof. Optionally, the densifier and / or densifier matrix includes metal. Optionally, the densifier consists of metal or the densifier matrix consists of metal and matrix material. Optionally, the densifier consists of metal. Optionally, the densifier and / or densifier matrix includes one or more metal components such as metal balls, metal frustums, metal cylinders or a combination thereof. Optionally, the metal includes a plurality of metal components. Where there is a densifier matrix, a plurality of metal components and the matrix material may be shaped to fit in the designated position in the bolus. Alternatively, the metal is in one or more components shaped to fit in the designated portion of the bolus either with or without matrix material.

[0017] Optionally, the active ingredient does not migrate into or through the densifier or densifier matrix when the bolus is in use (in particular, during storage or transport when oriented with the densifier at the top). Optionally, the active ingredient does not migrate into or through the densifier or densifier matrix when the bolus is submerged in a water bath at 40 °C for a period, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. Optionally, the active ingredient does not migrate into or through the densifier or densifier matrix when the bolus is submerged in a water bath system at 40 °C for a period, wherein the bolus is held vertical with the densifier above the active ingredient, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. Optionally, the densifier or the densifier matrix is inert with respect to the active ingredient when the bolus. Optionally, the densifier is inert with respect to the active ingredient when the bolus is submerged in a water bath system at 40 °C for a period, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. Optionally, the densifier or the densifier matrix is inert with respect to the active ingredient when the bolus is submerged in a water bath system at 40 °C for a period, wherein the bolus is held vertical with the densifier or densifier matrix above the active ingredient, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days.

[0018] In some embodiments, at least a portion of the densifier may comprise a ferromagnetic material. Optionally, the one or more metal components comprise a ferromagnetic material. In some embodiments, the densifier, metal components or metal pieces consist of a ferromagnetic material, or the densifier matrix consists of a ferromagnetic material and the matrix material.

[0019] In some embodiments, the densifier, such as the one of metal components in the densifier, may comprise one or more substantially chamfered edges, beveled edges, angled edges, tapered edgeds, rounded edges, planar surfaces or a curved surface. In some embodiments, the carrier includes one or more biodegradable polymers. Optionally, the carrier includes one or more materials selected from the list consisting of polycaprolactone (PCL), ethyl cellulose (EC), hydroxypropyl methylcellulose (HPMC), fumed silica / aerosil, castor wax, paraffin, stearic acid, microcrystalline wax, beeswax, polyethylene glycol (PEG), sodium starch glycolate, croscarmellose sodium, crospovidone, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate co-polymer (PVP / VA), a polyacrylic acid and / or their co-polymer variants, polyisobutylene, ethyl vinyl acetate (EVA), a functional wax with a melting point less than about 120°C, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes one or more biodegradable polymers selected from the list above, combinations thereof, combinations with talc thereof, and co-polymers thereof. Optionally, the carrier includes one or more polymers selected from the list consisting of ethyl cellulose, hydroxypropyl methyl cellulose, combinations thereof, and co-polymers thereof.

[0020] In some embodiments, the ethyl cellulose is about 48.0 to about 49.5% w / w ethoxyl basis. In some embodiments, the ethyl cellulose has a viscosity of about 10 cP, 20 cP, about 45 cP or about 100 cP at 5% w / w (80:20 toluene / ethanol) solution at 25 °C. In some embodiments, the ethyl cellulose has a viscosity of about 41 to about 49 mPa.s at 5% w / w (80:20 toluene / ethanol) solution at 25 °C. In some embodiments, the hydroxypropyl methylcellulose of the carrier is E3 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 19.0-24.0 %, apparent viscosity 2.4-3.6 mPa.s), E5 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 28.0-30.0 %, apparent viscosity 4.0-6.0 cps), E6 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 28.0-30.0 %, apparent viscosity 4.8-7.2 cps), E15 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 28.0-30.0 %, apparent viscosity 12.0-18.0 mPa.s), E50 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 28.0-30.0 %, apparent viscosity 40.0-60.0 mPa.s), and K100 LV (hydroxypropoxyl content 4.0-12.0 %, methoxyl content 19.0-24.0 %, apparent viscosity 80.0-120.0 mPa.s), or combinations thereof. The apparent viscosities listed above are measured according to the current USP (2% aqueous solution in water at 20 °C). In some embodiments, the hydroxypropyl methylcellulose has a viscosity from about 3 to about 100,000 cP (mPa s) measured in 2 % w / w aqueous solution at 20 °C. In some embodiments, the hydroxypropyl methylcellulose has a viscosity of about 100,000 cP (mPa s) measured in 2 % w / w aqueous solution at 20 °C. In some embodiments, the hydroxypropyl methylcellulose is E3 LV, E5 LV, E6 LV, E15 LV, E50 LV, and K100 LV, or combinations thereof.

[0021] Optionally, the carrier does not comprise hydrophobic fumed silica. Optionally, the carrier does not comprise a compound having the structure of formula (I) or (II), or a pharmaceutically acceptable salt thereof, wherein

[0022] (1) each of Yi, Y2 and Y3 is independently selected from the group consisting of Br and Cl;

[0023] (2) L is CH2, O, NH, or absent (preferably L is O or NH); and

[0024] (3) R is an optionally substituted group selected from the group consisting of OH, Ci-isalkyl, Ci-isalkoxy and Ci-salkyl-COOH; wherein if R is substituted, then it is substituted by one or more groups independently selected from the group consisting of Ci-salkyl, -OH, halogen, NH2, -COOH, -COCi-4alkyl, -COOCi-4alkyl, -NO2, and more particularly is substituted with one or more groups selected from the group consisting of Ci-2alkyl, -OH, halogen, NH2, -COOH, -COMe, and -COOMe.

[0025] Optionally, the carrier does not comprise a compound having the structure of formula (la), or a pharmaceutically acceptable salt thereof, wherein each of Yi, Y2 and Y3 is independently selected from the group consisting of Br and Cl; and

[0026] Z is:

[0027] (1) a group that will be cleaved off the carbon atom shown in formula la, such that Z is replaced by a hydrogen atom when the composition is exposed to the environment inside the rumen of a ruminant animal; or

[0028] (2) a group that will be cleaved off the carbon atom shown in formula la, such that Z is replaced by a hydrogen atom when compound la is contacted with a second activating compound that is comprised in said composition, wherein the second activating compound will come into contact with the compound la only when the composition is exposed to the environment inside the rumen of a ruminant animal.

[0029] In some embodiments, the casing includes one or more biodegradable polymers. In alternate embodiments, the casing includes one or more hydrophobic polymers. In some embodiments, the casing includes one or more non-biodegradable polymers, including polyethylene (including low-density polyethylene (LDPE, medium density polyethylene (MDPE), high-density polyethylene (HDPE), and combinations thereof), polypropylene (PP) and combinations thereof. Optionally, the casing includes one or more hydrophobic biodegradable polymers. Optionally, the casing includes one or more polymers selected from the list consisting of polycaprolactone (POL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly- D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. Optionally, the casing includes one or more polymers selected from the list consisting of high-density polyethylene (HDPE), polypropylene (PP), polycaprolactone (POL), polybutylene succinate (PBS), polybutylene succinate-co- adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D- lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. Optionally, the casing includes one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof.

[0030] In some embodiments, the active ingredient is a haloform. In some embodiments, the haloform is selected from the list of chloroform, bromoform, iodoform, or combinations thereof.

[0031] In some embodiments, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 8 weeks after administration. Optionally, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 20 weeks after administration. In some embodiments, the closed region is casing material joined by a closing means (ie a closer) such as stitching or, for example, casing material that is melted and resolidified to create a join. In some embodiments, the closed region includes a cap that is connected to the casing material. The cap can be joined to the casing material by stitching or melting and resolidification to create a join.

[0032] In preferred embodiments, the closed region (or cap) comprises the same material as the remainder of the casing and has the same thickness as the remainder of the casing. The join is also preferred to be melted and resolidified casing material of the same thickness as the main casing. The join is also preferred to be melted and resolidified casing material of the same material as the main casing.

[0033] In some embodiments, the densifier is the closed region. In this embodiment, the densifier is preferred to be a single piece of metal that joins the casing or a densifier matrix where the matrix material is casing material. Alternatively, there is a single piece of metal densifier as the closing region but additional pieces of metal and / or a matrix material in the densifier as a whole.

[0034] In preferred embodiments, the densifier is maintained (or remains) in position during use ie the densifier does not substantially move from its initial position relative to the core, in particular, the densifier does not migrate into the core in use or when stored or in transit and oriented with the densifier above the core. In preferred embodiments, the densifier is maintained (or remains) in position when the bolus is submerged in a water bath system at 40 °C for a period, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. In preferred embodiments, the densifier is maintained (or remains) in position when the bolus is submerged in a water bath system at 40 °C for a period, wherein the bolus is held vertical with the densifier above the core, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. In some embodiments, the densifier or densifier matrix maintains its initial position when stored or in transit and oriented or submerged in a water bath such that 95% or more, 90% or more, 80% or more, 70% or more, 60% or more, or 50% or more of the volume of the densifier or densifier matrix remains in the space not initially occupied by the core.

[0035] In some embodiments, a maximum diagonal length of the densifier or densifier matrix is greater than a maximum inner diameter of the casing. This embodiment has the advantage of making it difficult for the densifier to tilt in the casing such that fewer movements are available for the densifier to move within the bolus. Optionally, the position of the densifier within the casing, the shape of the casing, and the maximum diagonal length of the densifier are such that they prevent or impede the densifier from significant repositioning within the bolus during use, in particular, not migrating into the core during use. Optionally, the position of the densifier within the casing, the shape of the casing, and the maximum diagonal length of the densifier are such that they prevent or impede the densifier from significant repositioning within the bolus when the bolus is submerged in a water bath system at 40 °C for a period, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. Optionally, the position of the densifier within the casing, the shape of the casing, and the maximum diagonal length of the densifier are such that they prevent or impede the densifier from significant repositioning within the bolus when the bolus is submerged in a water bath system at 40 °C for a period, wherein the bolus is held vertical with the densifier or densifier matrix above the core, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. In these embodiments, it is preferred for the densifier to have a planar or flat surface facing the core rather than a rounded surface to even out the force of the densifier on the core. These embodiments may include spacing components or no spacing components. Optionally, the only spacing component is a void between the densifier and the casing. Alternatively, solid spacing components are included to either aid in fixing the densifier or prevent interaction between the densifier and the core. In some embodiments, the bolus may comprise a spacing component between the casing and the densifier. In this embodiment the spacing component may be combined with the densifier used to increase the width and / or a planar surface formed by both. In some embodiments, the bolus may comprise a spacing component between the core and the densifier. In some embodiments, the spacing component separates only a portion of the densifier or densifier matrix from the casing and / or core (ie other portions of the densifier or densifier matrix are in contact with the casing and / or core). In some embodiments, the spacing component is a void, for example, a void filled with gas such as air or nitrogen. In some embodiments, the spacing component is filled with a material other than casing or densifier or densifier matrix such as a veterinary acceptable excipient. The spacing component may also be casing material. Preferably the spacing component is impermeable, inert or unreactive, preferably impermeable. In some embodiments, the spacing component prevents contact between the densifier or densifier matrix and the core. In some embodiments, the spacing component prevents migration of the active ingredient between the densifier and the core, or through the densifier from the core. In some embodiments, the spacing component prevents migration of the active ingredient between the densifier and the core, or through the densifier from the core when the bolus is submerged in a water bath system at 40 °C for a period, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. In some embodiments, the spacing component prevents migration of the active ingredient between the densifier and the core, or through the densifier from the core when the bolus is submerged in a water bath system at 40 °C for a period, wherein the bolus is held vertical with the densifier above the core, where the period may be 25 days, 50 days, 75 days, 100 days or 150 days. For embodiments, where the spacing component is for preventing contact between the core and densifier, the spacing component is preferred to be planar such as a planar layer within the bolus or a coating of the densifier or portion of the densifier facing the core.

[0036] In addition or in the alternate, the spacing component fixes or retains the densifier in position. In some embodiments, the bolus may comprise a spacing component having a dimensional value that fixes the densifier in position in the bolus. Optionally and additionally, in some embodiments, the spacing component may have a dimensional value that substantially impedes or prevents the densifier from moving within the casing. In some embodiments, the spacing component separates the densifier, or a portion thereof, from the core. In some embodiments, the one or more spacing components extend, either partially or fully, from an inner surface of the casing across a diameter and / or length of the casing and / or core. In some embodiments, the one or more spacing components extending from the inner surface of the casing may be: one or more planar surfaces; one or more rods; one or more tabs; one or more ledges; one or more wedges or a combination thereof. Preferred spacing components are parallel to the end of the bolus or perpendicular to the wall of the bolus cylinder.

[0037] In some embodiments, the bolus is absent a spacing component and the densifier or densifier matrix is fixed or retained in a position relative to the casing and / or core due to variations in the thickness and the inner diameter of the casing, for example, the densifier may reside in a region of the bolus with thinner casing and be of a size (ie have a diameter or circumference) that cannot move to a region of the bolus with thicker casing. The advantage of this embodiment is to prevent or impede the densifier from moving within the casing from the initial location in use (ie during storage or transit, especially with the densifier oriented at the top with gravity pushing it towards the core).

[0038] Optionally, the spacing component coats the densifier or densifier matrix. Optionally, all of the densifier or densifier matrix is coated by the spacing component. Optionally, only a portion of the densifier or densifier matrix is coated by the spacing component, preferably the portion in contact with the core.

[0039] Optionally, the spacing component is a polymer (such as halogenated polymers incluidng polytetrafluoroethylene) or glass or stainless steel. Optionally, the spacing component is made from the options described for casing material. Optionally, the spacing is fixed to the casing using methods for closing the closed region or attaching a cap to the casing.

[0040] In another aspect, the present disclosure provides a method of administering a methane inhibitor to a ruminant animal, the method including administering to the rumen of the ruminant animal the bolus in accordance with this disclosure.

[0041] In another aspect, the present disclosure provides a method of reducing methane production in the rumen of a ruminant animal, the method including administering to the rumen of the ruminant animal a bolus in accordance with this disclosure. In embodiments of the methods of the disclosure, the bolus administers haloform to the rumen of the ruminant animal for at least about 8 weeks after administration. Optionally, the bolus administers haloform to the rumen of the ruminant animal for at least about 20 weeks after administration.

[0042] In embodiments of the methods of the disclosure, following administration of the bolus the bolus sinks below the liquid surface or to the bottom of the rumen.

[0043] In embodiments of the methods of the disclosure, the bolus remains in the rumen following administration for at least about 8 weeks or at least about 20 weeks.

[0044] In embodiments of the methods of the disclosure, following release of the active ingredient the bolus degrades in the rumen. Optionally, the degradation is until the remnants of the bolus are of a size that can safely pass through the ruminant.

[0045] In yet another aspect, the present disclosure provides a method of making a bolus, the method including: selecting a core, a casing having a closing region, and a densifier; inserting the core and densifier into the casing, closing the closing region of the casing to encapsulate or substantially encapsulates the core in the casing, thereby forming a closed region; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier.

[0046] In yet another aspect, the present disclosure provides a method of making a bolus, the method including: selecting a core, a casing having a closing region, and a densifier; inserting the core into the casing, inserting a densifier into the casing; closing the closing region of the casing to encapsulate or substantially encapsulates the core in the casing, thereby forming a closed region; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier; wherein the densifier is between the core and the closed region of the casing.

[0047] This method may be used to prepare bolus dosage forms according to the disclosure.

[0048] In some embodiments, inserting the core into the casing occurs prior to inserting the densifier into the casing. In some embodiments, inserting the densifier into the casing occurs prior to closing the closing region of the casing.

[0049] Optionally, the spacing component is inserted (and optionally joined to the casing) after inserting the core into the casing and before inserting the densifier. This is suitable for embodiments with the densifier between the core and the closing region.

[0050] Optionally, the spacing component is inserted (and optionally joined to the casing) after inserting the densifier into the casing and before inserting the core. This is suitable for embodiments with the densifier is not between the core and the closing region.

[0051] Optionally, the spacing component is joined to the casing by welding such as spin welding.

[0052] In some embodiments, closing the closing region comprises closing two sections of the casing together. Alternatively, the closing includes closing of a cap. For example, closing the closing region comprises attaching a cap to the closing region of the casing or closing a cap already attached to the casing over the core (optionally attaching to another portion of the closing region of the casing). In some embodiments, the closing is by sealing or stitching. Optionally, the closing includes soldering and / or spin welding.

[0053] In some embodiments, the closing region includes a means to close the casing and the casing is closed using the means to close. Optionally, the means to close the casing is a cap. In some embodiments, following closing of the closing region a closed region is formed from previously separate portions of casing that have been melted and / or soldered together.

[0054] Any embodiment herein shall be taken to apply mutatis mutandis to any other embodiment unless specifically stated otherwise.

[0055] The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purpose of exemplification only. Functionally- equivalent products, compositions and methods are clearly within the scope of the disclosure, as described herein.

[0056] Throughout this specification, unless specifically stated otherwise or the context requires otherwise, reference to a single step, composition of matter, group of steps or group of compositions of matter shall be taken to encompass one and a plurality (i.e. one or more) of those steps, compositions of matter, groups of steps or group of compositions of matter.

[0057] Further aspects of the present disclosure and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way of example and with reference to the accompanying drawings.

[0058] Brief description of the drawings

[0059] Figure 1 depicts the bromoform release profiles of Preparation 9Ai (release up to 120 days; PLA / PBAT 1.2 mm thickness with densifier matrix according to Table 1 present), Preparation 9Aii (release up to approximately 60 days; PLA / PBAT 1.2 mm thickness without densifier present) and Preparation 9Aiii (release up to approximately 45 days; PLA / PBAT 0.9 mm thickness with densifier matrix according to Table 1 present), as described in Example 2.

[0060] Figure 2 depicts Preparation 9Aii at the time that its measurement in the assay depicted in Figure 1 was stopped. The carrier matrix has expanded and broken the cap off the bolus. This was the third time that this had happened, previously addressed by resoldering the cap. Figure 3 depicts a bolus of the disclosure (100), which includes a casing (101), a core (102), a closed region (103) and a densifier (104).

[0061] Figure 4 depicts the release rates of bromoform from the boluses (100) F-SS and F-SS / W as described in Example 3.

[0062] Figure 5 depicts the release rates of bromoform from the boluses (100) F-SD and F-SHOTS as described in Example 4.

[0063] Figure 6 to Figure 16 depict various densifier shapes. The exemplified densifiers of these figures are made from steel.

[0064] Figure 17 depicts the value of the maximum diagonal length (denoted “x”) of a densifier (104).

[0065] Figure 18 depicts an embodiment of the densifier illustrated in Figure 17 where the value of the maximum inner diameter (denoted “D”) of the casing is smaller than the value of the maximum diagonal length (x) of the densifier.

[0066] Figures 19A-19F depict boluses having a densifier or densifier matrix located at various positions with or without one or more spacing components.

[0067] Figure 20 depicts boluses (100), 9H-74A and 9H-74B after being cut open after a period of testing. 9H-74A was cut open after 88 days of testing and 9H-74B was cut open after 75 days of testing. As described in Example 6, in both cases, the densifiers (104) moved from an initial position near the cap (103) but had not sunk into the core (102) or moved significantly from the initial position at the end of the core (102).

[0068] Figure 21 depicts boluses (100), 9I-72, 9H-74a and 9H-74b after being cut open after 74 days of testing. As described in Example 6, the densifiers (104) had sunk into the core (102) and moved from an initial position of the end of the core (102).

[0069] Figure 22 depicts the release rate of the boluses (100) 9I-72, 9H-74a and 9H-74b and the release rate of the boluses (100) 9H-74A and 9H-74B in a water bath testing system, as described in Example 6. Detailed description of the embodiments

[0070] In one aspect, the present disclosure provides a bolus including: a core including at least one active ingredient and at least one carrier; a densifier; a casing that encapsulates or substantially encapsulates the core; wherein the casing includes a closed region (i.e.: a region that is closed during manufacture to encapsulate the core in the casing); wherein the core is separated from the closed region and the densifier is between the core and the closed region; and wherein the bolus is formulated to remain in the rumen following administration.

[0071] One class of compounds that are difficult to deliver to animals are hydrophobic compounds. A further class of compounds that are difficult to deliver to animals, particularly in a sustained release, are volatile or somewhat-volatile compounds. The properties of these compounds present challenges to developing technology for the sustained release of these hydrophobic and / or volatile / somewhat-volatile substances, particularly via an animal’s stomach. Haloforms such as bromoform are such substances. Surprisingly, the inventors have developed an extremely extended release (months) dosage form for delivering hydrophobic and / or volatile / somewhat-volatile substances to the rumen of ruminants, a relatively little studied environment relative to the gastrointestinal tract of single stomached animals. Surprisingly, the inventors have improved the reliability and robustness of the device or dosage form through positioning the densifier between the closed region and the core.

[0072] One specific purpose to administer substances to animals is to reduce the adverse effects of agriculture. For instance, various methane and nitrification inhibitors are known to be administered to animals to reduce or mitigate the adverse effects of the methane and nitrogen-containing compounds produced by the animals.

[0073] However, despite current efforts, climate change is creating a wide range of environmental and social impacts globally. It is widely understood that these impacts will only continue to increase over time. As a result, there has been a global push to reduce harmful greenhouse gas (GHG) emissions in an effort to avoid the worst effects of climate change.

[0074] The agricultural sector is considered to be a major source of GHG emissions. Total emissions of methane from global livestock accounts for an estimated 7.1 gigatons of CO2-equivalent per year, representing 14.5% of all anthropogenic GHG emissions. Therefore, this sector will play a key role in reducing overall GHG emissions.

[0075] The main GHGs released by agriculture are methane (CH4) and nitrous oxide (N2O), with the main source of methane emission attributed to livestock. Most methane is emitted when cattle, or other ruminant animals, burp. The amount of methane produced for each farm is directly related to the total animal feed intake, commonly measured as dry matter intake (DMI).

[0076] Countries which have a strong agricultural sector, such as New Zealand and other countries, face challenging goals in reducing agricultural emissions. For instance, the New Zealand government has introduced policies aimed to reduce methane emission by 24-50% before 2050. In New Zealand livestock methane production is estimated to comprise as much as half of the country's total GHG emissions. The reduction of methane is a critical component of meeting targets for emissions of GHGs and reducing the effects of global warming.

[0077] Release of GHGs by animals also has adverse effects on animal productivity. Any feed that is converted to a compound which is subsequently expired or released by the animal, is an energy source that has not been converted to a productive use. Accordingly, for efficiency, it is important to optimise conversion of feeds into animal productivity, including in the form of weight gain or milk production.

[0078] Definitions

[0079] Unless otherwise herein defined, the following terms will be understood to have the general meanings which follow.

[0080] A veterinary acceptable excipient is an excipient which upon administration to an animal subject is typically not deleterious to the subject. The skilled person will appreciate that in general veterinary acceptable excipients include pharmaceutically acceptable (i.e.: acceptable for humans) excipients.

[0081] As used herein “haloform” is CHX3 where X is a halogen and each X atom may be a different halogen. Thus, “haloform” includes CHCIBr2 and the like. As used herein, “mixed haloform” refers to haloforms where not every X attached to the carbon atom is the same. In some embodiments, each X atom is the same.

[0082] As used herein, “degrade” and “degradation” do not require full break down of the bolus into other matter and full absorbance by the rumen fluid, but that instead only require that the bolus breaks sufficiently such that it may leave the rumen, for instance by passing through the digestive tract of the animal or being regurgitated.

[0083] As used herein, “feeds” refers to dry matter intake (DMI), supplements, grazing pasture, grains, or other feedstock.

[0084] As used herein, the term "effective amount" means that amount of an active ingredient or compound for delivery to the rumen that will elicit the biological or medical response of a tissue, system, or animal that is being sought, for instance, by a researcher or veterinarian. Furthermore, the term "therapeutically effective amount" means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, prevention, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function. For instance, a therapeutically effective amount of methane inhibiting agent such as a haloform reduces the methane output of an animal, preferably a ruminant.

[0085] As used herein, the term “substantially” means enough to achieve the relevant function. For example, a core is substantially encapsulated by casing when it is sufficiently surrounded by casing that the core is retained in the casing ie encapsulated. “Substantially” is also used herein in reference to shapes to encompass variations from a base shape. For instance, a densifier which is substantially cylindrical in shape includes a three-dimensional shape a curved surface and a planar face at each end of the curved surface. A substantially cylindrical densifier includes a densifier with a uniformly circular cross-section in a plane perpendicular to the curved surface. A substantially cylindrical densifier also includes a densifier with a non-uniform cross-section, or an elliptical or oval cross-section or any other two-dimensional shape in a plane perpendicular to the curved surface. Further, a substantially cylindrical densifier also includes three-dimensional shapes where the two planar faces are not exactly parallel to each other or are not exactly perpendicular to the curved surface, for example, these faces could have some degree of rounding. Further, a substantially cylindrical densifier includes cylindrical densifiers with chamfered edges, bevelled edges, angled edges, tapered edges or rounded edges.

[0086] As used herein, the term “position” or “positioned” refers to a location in the bolus. The location is usually determined by reference to one or more of the closed portion, the core, the densifier, and the spacing component(s). The skilled person will understand that minor deviations or movements that do not impact function are acceptable within the position.

[0087] It must be noted that as used herein and in the appended claims, the singular forms “a”, “an” and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a polymer” may include a plurality of polymers and a reference to “at least one carrier” may include one or more carriers, and so forth.

[0088] The term “and / or” can mean “and” or “or”.

[0089] The term “(s)” following a noun contemplates the singular or plural form, or both.

[0090] Various features of the disclosure are described with reference to a certain value, or range of values. These values are intended to relate to the results of the various appropriate measurement techniques, and therefore should be interpreted as including a margin of error inherent in any particular measurement technique. Some of the values referred to herein are denoted by the term “about” to at least in part account for this variability. The term “about”, when used to describe a value, may mean an amount within ±25%, ±10%, ±5%, ±1% or ±0.1% of that value.

[0091] As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps.

[0092] Carrier A carrier as used herein is a compound that can be mixed with an active ingredient without changing the chemical structure of the active ingredient. Preferably, the carrier when used in a bolus of the disclosure delays the release of the active ingredient from the bolus. Optionally, the carrier is solid, semi-solid or liquid.

[0093] A range of substances may be suitable for use as a carrier in the boluses of the present disclosure and the following examples are not limiting. Numerous large molecules and / or particles dispersible or miscible in a haloform with branching or surface modification able to associate with a haloform are suitable. For instance, the carrier may be selected from the list of waxes, myristic acid, stearic acid, stearyl alcohol, cetyl alcohol, cetostearyl alcohol or a combination thereof. The carrier may be a waxy substance, for example, the carrier may be selected from the list of bee’s wax, paraffin wax, PEG4000, Carnauba, castor wax, Candellila, Jojoba wax, or Lanolin wax or a combination thereof. The carrier may comprise a mixture of two or more components, such as at least one relatively polar substance with a relatively non-polar substance. As a result, the overall polarity of the carrier may be adjusted to achieve the desired affinity for the active ingredient. This can be used to achieve a desired release rate for the active ingredient. For instance, in some forms the carrier may include a mixture of paraffin wax (a mixture of alkanes with no polar functional groups) and castor wax and / or carnauba wax (which have a relatively high amount of polar functional groups).

[0094] In some embodiments, the carrier includes one or more biodegradable polymers. In some embodiments, the carrier consists of one or more biodegradable polymers. In some embodiments, the carrier includes two or more biodegradable polymers. In some embodiments, the carrier consists of two or more biodegradable polymers. In some embodiments, the carrier does not include a wax.

[0095] In some embodiments, the carrier includes one or more materials selected from the list consisting of polycaprolactone (PCL), ethyl cellulose (EC), hydroxypropyl methylcellulose (HPMC), fumed silica / aerosil, castor wax, paraffin, stearic acid, microcrystalline wax, beeswax, polyethylene glycol (PEG), sodium starch glycolate, croscarmellose sodium, crospovidone, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate co-polymer (PVP / VA), a polyacrylic acid and / or their co-polymer variants, polyisobutylene, ethyl vinyl acetate (EVA), a functional wax with a melting point less than about 120°C, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes one or more biodegradable polymers selected from the list above, combinations thereof, combinations with talc thereof, and co-polymers thereof.

[0096] In some embodiments, the carrier includes one or more materials selected from the list consisting of carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate co-polymer (PVP / VA), a polyacrylic acid and / or their co-polymer variants, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes one or more materials selected from the list consisting of polyisobutylene, ethyl vinyl acetate (EVA), a functional wax with a melting point less than about 120°C, combinations thereof, combinations with talc thereof, and co-polymers thereof.

[0097] In some embodiments, the carrier includes one or more cellulose derivative, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier consists of one or more cellulose derivative, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes ethyl cellulose, hydroxypropyl methylcellulose, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier consists of ethyl cellulose, hydroxypropyl methylcellulose, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes ethyl cellulose. In some embodiments, the carrier includes hydroxypropyl methylcellulose.

[0098] In some embodiments, the ethyl cellulose is about 15% to about 40%, about 15% to about 30%, or about 20% to about 30% w / w of the core. In some embodiments, the ethyl cellulose is about 20.1% w / w of the core. In some embodiments, the ethyl cellulose is about 27.3% w / w of the core.

[0099] In some embodiments, the hydroxypropyl methylcellulose is about 10% to about 30%, about 10% to about 25%, or about 12% to about 20% w / w of the core. In some embodiments, the hydroxypropyl methylcellulose is about 14.3% w / w of the core. In some embodiments, the hydroxypropyl methylcellulose is about 19.6% w / w of the core.

[0100] In some embodiments, the ethyl cellulose is about 48.0 to about 49.5% w / w ethoxyl basis.

[0101] In some embodiments, the ethyl cellulose has a viscosity of about 10 cP, 20 cP, about 45 cP, or about 100 cP at 5% w / w (80:20 Toluene / Ethanol) solution at 25 °C. In some embodiments, the ethyl cellulose has a viscosity of about 41 to about 49 mPa.s at 5% w / w (80:20 Toluene / Ethanol) solution at 25 °C.

[0102] In some embodiments, the hydroxypropyl methylcellulose of the carrier is E3 LV, E5 LV, E6 LV, E15 LV, E50 LV, and K100 LV, or combinations thereof.

[0103] In some embodiments, the hydroxypropyl methylcellulose has a viscosity from about 3 to about 100,000 cP (mPa s) measured in 2 % w / w aqueous solution at 20 °C. In some embodiments, the hydroxypropyl methylcellulose has a viscosity of about 100,000 cP (mPa s) measured in 2 % w / w aqueous solution at 20 °C. In some embodiments, the hydroxypropyl methylcellulose has a viscosity from about 75,000 to about 140,000 mPa.s measured in 2 % w / w aqueous solution at 20 °C. In some embodiments, the hydroxypropyl methylcellulose has a methoxyl content from about 19% to about 24%. In some embodiments, the hydroxypropyl methylcellulose has a hydroxypropyl content from about 7% to about 12%. In some embodiments, the hydroxypropyl methylcellulose has a methoxyl content from about 19% to about 24%, and a hydroxypropyl content from about 7% to about 12%.

[0104] In some embodiments, the hydroxypropyl methylcellulose is E3 LV, E5 LV, E6 LV, E15 LV, E50 LV, and K100 LV, or combinations thereof.

[0105] In some embodiments, the carrier comprises a channeling agent. Channeling agents are substances that are soluble in the gastrointestinal tract and leach from the formulation, leaving capillaries through which the active ingredient may diffuse in order to be released. In some embodiments, the channeling agent is a hydrophilic polymer and / or polyol. In some embodiments, the channeling agent is selected from the list consisting of alginate, an osmotic agent (such as NaCI, mannitol), a phospholipid (such as lecithin), an alcohol or derivative (such as glycerol, triacetin), a polyethylene glycol (PEG), sorbitol, citric acid, sodium bicarbonate, triacetin, ethyl oleate, or suitable polymers such as sodium starch glycolate, croscarmellose sodium and crospovidone. In some embodiments, the carrier does not comprise a channeling agent.

[0106] In some embodiments, the carrier does not include hydrophobic fumed silica. In some embodiments, the carrier does not include silica. In some embodiments, the carrier includes hydrophilic silica.

[0107] In some embodiments, the carrier does not comprise a compound having the structure of formula (I) or (II), or a pharmaceutically acceptable salt thereof, wherein

[0108] (1) each of Yi, Y2 and Y3 is independently selected from the group consisting of Br and Cl;

[0109] (2) L is CH2, O, NH, or absent (preferably L is O or NH); and

[0110] (3) R is an optionally substituted group selected from the group consisting of OH, Ci-isalkyl, Ci-isalkoxy and Ci-salkyl-COOH; wherein if R is substituted, then it is substituted by one or more groups independently selected from the group consisting of Ci-salkyl, -OH, halogen, NH2, -COOH, -COCi-4alkyl, -COOCi-4alkyl, -NO2, and more particularly is substituted with one or more groups selected from the group consisting of Ci-2alkyl, -OH, halogen, NH2, -COOH, -COMe, and -COOMe.

[0111] In some embodiments, the carrier does not comprise a compound having the structure of formula (la), or a pharmaceutically acceptable salt thereof, wherein each of Yi, Y2 and Y3 is independently selected from the group consisting of Br and Cl; and

[0112] Z is:

[0113] (1) a group that will be cleaved off the carbon atom shown in formula la, such that Z is replaced by a hydrogen atom when the composition is exposed to the environment inside the rumen of a ruminant animal; or

[0114] (2) a group that will be cleaved off the carbon atom shown in formula la, such that Z is replaced by a hydrogen atom when compound la is contacted with a second activating compound that is comprised in said composition, wherein the second activating compound will come into contact with the compound la only when the composition is exposed to the environment inside the rumen of a ruminant animal.

[0115] Optionally, the at least one carrier is about 5 to about 80%, about 10 to about 70%, about 20 to about 60%, about 30 to about 50% w / w of the core.

[0116] In some embodiments, the casing is uniform ie without specific portions designed to speed or slow release. In another embodiments, the closed region is uniform ie without specific portions designed to speed or slow release other than the sealed region).

[0117] Core

[0118] In some embodiments, the core is of uniform composition. For example, the core does not include a region that is excipient only without dispersed active ingredient.

[0119] In some embodiments, the core does not comprise an osmotic tablet. In some embodiments, the core is not connected to any additional internal element (ie excluding the casing as that is external) of the bolus designed to facilitate release of the active ingredient. In some embodiments, the core is not contacted by any additional internal element of the bolus designed to facilitate release of the active ingredient. In some embodiments, the core does not include a shaft extending therefrom.

[0120] Casing

[0121] In some embodiments, the casing encapsulates the core. In some embodiments, the casing substantially encapsulates the core ie the core is not fully encapsulated but sufficiently surrounded by casing to retain the core within the casing. A substantially encapsulated core has about 70 to about 99%, about 80 to about 99%, about 85 to about 99% or about 90 to about 99% of the surface area of the core covered by the casing.

[0122] In some embodiments, the casing does not comprise an opening. In some embodiments, release of the active ingredient via the casing is consistent across the regions where the core directly contacts the casing (eg where there is no densifier between the core and casing).

[0123] In some embodiments, the casing includes one or more biodegradable polymers. In some embodiments, the casing consists of one or more biodegradable polymers. In some embodiments, the casing does not include a non-biodegradable polymer.

[0124] In alternate embodiments, the casing includes one or more hydrophobic polymers. Optionally, the casing includes one or more hydrophobic biodegradable polymers. In alternate embodiments, the casing consists of one or more hydrophobic polymers. Optionally, the casing consists of one or more hydrophobic biodegradable polymers.

[0125] In some embodiments, the casing includes one or more ester-based polymers.

[0126] In some embodiments, the casing includes one or more polymers selected from the list consisting of high-density polyethylene (HDPE), polypropylene (PP), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co- adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D- lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. In some embodiments, the casing consists of one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co- adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D- lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more polymers selected from the list consisting of high-density polyethylene (HDPE), polypropylene (PP), combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. In some embodiments, the casing consists of one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof.

[0127] In some embodiments, the casing includes one or more of poly lactic acid (PLA), poly glycolic acid (PGA), poly lactic glycolic acid (PLGA), polypropylene, Polycaprolactone (PCL), poly(d-lactic acid) (PDLA), Polybutylene succinate (PBS), Polybutylene adipate terephthalate (PBAT), SLA polymer, ABS, combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more of polylactic acid (PLA), poly-butylene succinate co-adipate (PBSA), poly-butylene succinate (PBS), polyhydroxybutyrate-co-hydroxy valerate, poly vinyl acetate (PVA), Polybutylene adipate terephthalate (PBAT), polycaprolactone (PCL), wood flour and cellulosic materials, ethyl cellulose and hydroxypropyl methyl cellulose, combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof. In some embodiments, the casing consists of one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof.

[0128] In some embodiments, the PLA:PBAT ratio is from about 95:5 to about 70:30 wt / wt, from about 95:5 to about 80:20 wt / wt, or from about 95:5 to about 85:15 wt / wt. In some embodiments, the PLA:PBAT ratio is about 90:10 wt / wt.

[0129] Blends of such substances can be particularly advantageous. For instance, mixing / blending a polybutylene polymer such as PBAT with PLA increases the plasticity and strength of the casing compared to a casing made of PLA alone, while preserving the biodegradability of the casing material. This stability improving effect is particularly beneficial when using for instance haloforms as methane inhibiting agents, because such compounds can otherwise promote brittleness of the casing material. Furthermore, the use of a polybutylene polymer / PLA blend compared to PLA alone, improves the durability of the casing and reduces the risk of fracturing under mechanical stress such as when placed into the rumen of an animal.

[0130] The components used or mixed to form the casing material may be selected according to their suitability regarding their use for forming the bolus casing. Upon heating for shaping the bolus casing, the composition should not become too viscous for 3D printing or injection moulding and blending of two or more polymers should result in a homogeneous mixture without extensive bubbles formation.

[0131] The casing of the bolus may for instance comprise biodegradable and / or non- biodegradable materials, but preferably comprises biodegradable polymers. Such materials may be synthetic, or naturally, or essentially naturally derived. It is preferred that materials are selected from biodegradable polymers. Examples of such polymers include, without limitation, poly lactic acid (PLA), polybutylene terephthalate (PBT), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS) and / or polybutylene succinate adipate (PBSA). Biodegradability allows repeated administration of boluses, while preventing the accumulation of bolus materials in the ruminant animal’s body, since the bolus components can be at least partially or even fully degraded in the rumen milieu. Nevertheless, it is understood that even if a bolus casing is biodegradable, it will not fully degrade to a degree that the bolus breaks down for the duration of at least 7 days when kept in the rumen for this time. Suitable non-biodegradable polymers include high-density polyethylene (HDPE), polypropylene (PP), combinations thereof, and copolymers thereof.

[0132] Accordingly, the casing for any bolus described herein may be configured to have sufficient structural integrity to remain intact for a predetermined period of time. In a preferred embodiment, the casing may be configured to degrade over a predetermined period of time. A predetermined period of time may mean the period of time over which the methane inhibiting agent is to be released to the animal. In a particularly preferred embodiment, the predetermined period of time may be at least two months, preferably six months, and more preferably 12 months.

[0133] Alternatively, the casing may be made from one or more non-adsorbent materials, i.e. materials into which, or through which, the methane inhibiting agent does not migrate. Using a non-absorbent material for the casing can assist with controlling the rate of release of the methane inhibiting agent(s), for instance in a bolus comprising one or more openings, in a bolus with a casing which is able to form one or more openings or in an open-ended bolus. For instance, in these embodiments, the concentration of the methane inhibiting agent(s) in the core is not decreased by their absorption into / or passing through the casing material.

[0134] In some embodiments, at least the non-closing region portion of the casing is uniform. Optionally, the active ingredient migrates through the casing in use (ie upon administration).

[0135] In some embodiments, the casing comprises one or more excipients. In a preferred embodiment the one or more excipients includes a plasticizer, hardener and / or colorant. As used herein, “hardener” refers to a cross-linking agent and / or an excipient whose inclusion increases the Shore D hardness of the casing.

[0136] In some embodiments, the casing further comprises a compound selected from a nucleating agent or stabilizer. In some embodiments, the casing does not comprise a nucleating agent and / or a stabilizer. The thickness of the casing may be selected to contribute to the rate of release of the methane inhibiting agent, i.e. a relatively thicker casing will have a relatively slower release rate than a relatively thinner casing. This is particularly the case if the casing material is permeable for the methane inhibiting agent. In some embodiments, the casing has a material thickness less than about 2 mm, and preferably a material thickness in the range of about 0.3-1.5 mm. In some embodiments, the casing has a material thickness less than about 1.5 mm, less than about 1.3 mm, or less than about 1 mm. In some embodiments, the casing has a material thickness greater than about 0.8 mm, greater than about 1 mm or greater than about 1.1 mm. In some embodiments, the casing has a material thickness of about 0.9 mm. In some embodiments, the casing has a material thickness of about 1.2 mm. For boluses comprising a casing with one or more openings, thicker casings may be applicable, such as up to about 5 mm of casing wall thickness.

[0137] Densifier

[0138] A densifier is a component that increases the density of the bolus. In some embodiments, the densifier is a densifier matrix, for example, dense particles dispersed through a carrier (the carrier is optionally also a densifier but often not a densifier on its own). A densifier typically has a density greater than 1.0 g / cm3. Optionally, the densifier has a density from about 2.0 g / cm3to about 10 g / cm3, about 3.0 g / cm3to about 10 g / cm3, about 4.0 g / cm3to about 10 g / cm3, about 5.0 g / cm3to about 10 g / cm3, or about 6.0 g / cm3to about 10 g / cm3. Steel ball bearings have a density of 7.8 g / cm3and are suitable for inclusion as a densifier or within a densifier matrix. Preferably, the densifier increases the density of the bolus to a density greater than 1.0 g / cm3. In some embodiments, the densifier is a densifier matrix comprising densifier and at least one veterinary acceptable excipient. In some embodiments, the densifier is not a matrix, meaning that the densifier does not contain a further component beyond the densifier itself.

[0139] Optionally, there are no additional elements within or passing through the densifier.

[0140] In some embodiments, the densifier and / or densifier matrix is in direct contact with the core. In some embodiments, the densifier and / or densifier matrix is in direct contact with the closed region. Preferably, the densifier is in direct contact with the core and the closed region. In some embodiments, the densifier and / or densifier matrix does not directly contact one or both of the core and the closed region (for instance, a further spacing component may be present preventing directing contact).

[0141] In some embodiments, the densifier matrix includes a matrix material more hydrophobic than the at least one carrier. In some embodiments, the densifier matrix includes a wax. In some embodiments, the densifier matrix includes a matrix material selected from castor wax, paraffin wax, stearic acid, microcrystalline wax, beeswax, stearyl alcohol, white wax, yellow wax, cetyl alcohol, cetyl esters wax, carnauba wax, ethyl vinyl acetate (EVA), and combinations thereof. In some embodiments, the densifier matrix includes paraffin wax. In some embodiments, the densifier matrix consists of paraffin wax. In some embodiments, the densifier matrix includes one or more nonfunctional hydrocarbon waxes, preferably with a melting point between 50 °C and 100 °C. In some embodiments, the densifier matrix consists of one or more non-functional hydrocarbon waxes, preferably with a melting point between 50 °C and 100 °C.

[0142] In some embodiments, the densifier and / or densifier matrix includes metal. In some embodiments, the densifier and / or densifier matrix includes a metal oxide. In some embodiments, the densifier and / or densifier matrix includes steel, iron, iron oxide, zinc, zinc oxide and combinations thereof. In some embodiments, the densifier and / or densifier matrix includes steel. In some embodiments, the densifier and / or densifier matrix includes iron and / or iron oxide. In some embodiments, the densifier and / or densifier matrix does not include zinc and / or zinc oxide. Zinc is known to interact with oragnohalides, such as haloforms, potentially meaning that the incorporation of zinc (and / or zinc oxide) into a bolus comprising haloform may be disadvantageous.

[0143] In some embodiments, the densifier and / or densifier matrix includes the densifier in the shape of one or more balls, cylinders, frustums or combinations thereof Figures 6 to 16 depict examples of these densifier embodiments. These depictions are exemplary and are not to be considered in any way limiting.

[0144] In some embodiments, the densifier and / or the densifier matrix may include a densifier in a combination shape comprising one or more frustums and a cylinder. Examples of these embodiments are depicted in Figures 14 and 15. In some embodiments, the densifier and / or the densifier matrix may include a frustum-cylindrical densifier comprising a frustum-shaped region and a cylindrical region. In this embodiment, a lower basal portion of the frustum-shaped region has a diameter similar to the diameter of the cylindrical region. An example of this embodiment is depicted in Figure 14.

[0145] In some embodiments, the densifier and / or the densifier matrix includes a frustum- cylinder-frustum densifier comprising a first frustum-shaped region, a second frustumshaped region and a cylindrical region between the first frustum-shaped region and the second-frustum shaped region. In this embodiment, the diameter of the cylindrical region may be substantially equal to the diameter of a lower basal portion of the first frustumshaped region and the second frustum-shaped region. An example of this embodiment is depicted in Figure 15. The chamfer radius of the first and second-frustum shaped regions is about 1 .5 mm, 2 mm or 2.5 mm.

[0146] In some embodiments, the densifier and / or the densifier matrix includes the densifier made of metal. In some embodiments, the densifier and / or densifier matrix includes the densifier made of steel. Examples of these embodiments are depicted in Figures 6 to 16.

[0147] In some embodiments, the densifier and / or the densifier matrix includes the densifier comprising one or more chamfered edges. Sharp edges may irritate and / or affect the lining of the animal’s stomach or rumen in the event of the densifier being exposed inside the animal’s stomach or rumen. An advantage of this embodiment is reducing or eliminating sharp edges. Examples of these embodiments are depicted in Figures 7 to 15.

[0148] In some embodiments, the cylindrical densifiers, the frustum-shaped densifiers and / or the densifiers comprising a combination of cylindrical and / or frustum-shaped regions may comprise one or more chamfered and / or beveled edges. Examples of these embodiments are depicted in Figures 7 and 15.

[0149] In some embodiments, the densifier and / or the densifier matrix includes the densifier comprising edges having no chamfer or a chamfer radius value which is less than 1 mm. An example, of a dual flat ended cylindrical metal densifier of this type of this embodiment is depicted in Figure 7.

[0150] In some embodiments, the densifier and / or the densifier matrix includes the densifier comprising one or more chamfered edges having a chamfer radius value greater than 1 mm. Examples of dual flat ended cylindrical metal densifiers of this with small and large chamfers are depicted in Figures 8 (about 1 mm chamfer depth and width and squared edges) and 15 (about 5mm chamfer depth and width and rounded edges).

[0151] In some embodiments, the densifier and / or densifier matrix includes the densifier as particles. Densifier balls and / or particles are advantageous given that they are less likely to aggravate the rumen than densifiers with sharp edges. Similarly, small and stable densifiers such as steel ball bearings or steel particles are also advantageous given that they are biologically inert, and unlikely to aggravate the digestive tract either chemically or physically, and can potentially be excreted by the animal. Similarly, biologically compatible yet unstable densifiers such as iron and iron oxide are also favourable: such densifiers can break down to particles (if not already delivered as such) in the digestive tract, facilitating excretion without aggravating the digestive tract.

[0152] Optionally, the densifier matrix is about 70 to about 99%, about 80 to about 99%, about 85 to about 99%, about 90 to about 95% w / w densifier particles. Optionally, the matrix material for the densifier matrix is about 1 to about 30%, about 1 to about 20%, about 1 to about 15%, about 5 to about 10% w / w of the densifier matrix.

[0153] The skilled person is able to calculate an approximate density for a densifier based on its components and able to measure density of a densifier experimentally.

[0154] Optionally, the densifier matrix comprises particles or balls of densifier in the matrix material. Optionally, the particles or balls are about 0.1 to about 0.9, about 0.1 to about 0.6, about 0.2 to about 0.6, or about 0.5 mm in diameter.

[0155] In some embodiments, the densifier or densifier matrix 104 is located within the casing 101 towards the closed region 103 of the bolus as illustrated, for example, by Figures 19A and 19D-19F. In some embodiments, the densifier or densifier matrix 104 is located within the casing 101 below the cap 110. In some embodiments, the densifier or densifier matrix 104 is located within the casing 101 and sized and / or dimensioned to engage the cap 110. In some embodiments, the densifier or densifier matrix 104 is located along a side of the casing as illustrated, for example, by Figure 19B. In some embodiments, the densifier or densifier matrix 104 is located within the casing 101 in a region of the bolus opposite to the closed region 103 as illustrated, for example, by Figure 19C. In some embodiments, the bolus is absent a cap and the densifier or densifier matrix 104 forms part of the closed region 103 as illustrated, for example, by Figure 19D.

[0156] In some embodiments, the maximum diagonal length of the densifier is greater than the maximum inner diameter of the casing. The advantage of these embodiments is that the densifier in the casing is substantially prevented from certain types of repositioning such as tilting within the bolus. This lessens the propensity for the densifier to reposition during use, e.g., migrate into the core of the bolus. A densifier whose maximum diagonal length is lesser than the maximum inner diameter of the casing may substantially re-orient and / or re-position in such a way that the densifier migrates into the core. During storage and / or transport, boluses tend to be in one orientation for a long period of time and the orientation may have the densifier at the top. The migration of the densifier in the core during storage or transit could result in the densifier displacing at least a portion of the core and changing locations within the bolus over time. The rumen is also a robust environment and a better fixed densifier could prevent migration due to the environment. An example of densifiers substantially retaining their initial orientation and position and consequently not sinking into the core is depicted in Figure 20. In contrast, an example of densifiers sinking into the core of the bolus is depicted in Figure 21.

[0157] In some embodiments, as depicted in Figure 17, the maximum diagonal length (denoted “x”) may be calculated by the following formula using Pythagoras’ theorem: x = (h — 2r)2+ d2where x = maximum diagonal length; h = height of the densifier; d = diameter of the cross-sectional area of the densifier; r = radius of the curved edge.

[0158] As the value of the radius (r) increases, the value of the maximum diagonal length (x) tends towards the value of the diameter (d). If the value of (2*r) is equal to the thickness (h), the value of the maximum diagonal length (x) becomes equal to the value of the cross-sectional diameter (d) of the densifier.

[0159] In some embodiments, the value of the maximum inner diameter (denoted “D”) of the casing is smaller than the value of the maximum diagonal length (x) of the densifier. This prevents or impedes the densifier from tilting in use (ie during storage or transit or a water bath or upon administration (in particular when oriented with the densifier at the top and gravity pushing the densifier towards the core) and lessens the propensity to migrate when the bolus is oriented with the densifier at the top. When the densifier also has a planar surface that has even force on the core, the propensity to migrate when the bolus is oriented with the densifier at the top is further reduced. An example of this embodiment is depicted in Figure 18.

[0160] In some embodiments, as depicted in Figure 18, the maximum inner diameter of the casing (denoted “D”) may be calculated in the following manner:

[0161] D = d + (2 * c) where D = maximum inner diameter of the casing; d = diameter of the cross-sectional area of the densifier; c = distance between the densifier and inner wall of the casing.

[0162] In order to prevent or impede re-orientation of the densifier in use, the value of maximum diagonal length (x) of the densifier must be greater than the maximum inner diameter (D) of the casing. This implies that the following dimensional values are determined by the following formula: where h = height of the densifier; r = radius of the curved edges; d = diameter of the cross-sectional area of the densifier; c = distance between the densifier and inner wall of the casing.

[0163] Optionally, the dimensional value of the spacing component between the inner wall of the casing and the densifier may further substantially impede or prevent the densifier from moving from an initial location within the casing, for example, in transport, storage or upon administration. In some embodiments, the bolus may comprise a spacing component having a dimensional value that is large enough to substantially impede or prevent the densifier from moving from position within the casing in transport, storage or upon administration. The may also prevent the densifier from compressing the core or pressing the core material to the inner wall of the casing. The advantage of this embodiment is a more reproducible release profile for the active ingredient, as movement of the densifier does not alter the forces on the core and casing and thereby alters release of the active ingredient.

[0164] In some embodiments, the densifiers having planer surfaces as illustrated for example, in Figures 7-15 are associated with a greater surface area in contact with the core and more diffuse and more constant force on the core than the densifier having a curved surface as illustrated in Figure 6, where the force is concentrated. An advantage of this configuration that may minimize or reduce the densifier from re-orienting and / or repositioning with respect to the core, e.g., sinking into the core of the bolus in storage or transport due to gravity.

[0165] In some embodiments, changes to the dimensions and / or the location of the core in the bolus due to the densifier compressing the core and / or sinking into the core may be disadvantageous. A displaced and / or a compressed core may impact one or more performance characteristics (such as release rate of the active ingredient) of the bolus and / or the structural integrity of the bolus upon administration. The above embodiments prevent or reduce the incidence of these disadvantages.

[0166] Spacing component

[0167] Figures 19A-19E illustrate embodiments of one or more spacing components 1905 for separating the densifier or densifier matrix, or a portion thereof, from the casing and / or core. Additionally, the one or more spacing components 1905 may fix or retain the densifier or densifier matrix in a position relative to the casing 101 and / or core 102. In some embodiments, the one or more spacing components are located between the core and the densifier as illustrated, for example, by Figures 19A-D. In some embodiments, the one or more spacing components extend, either partially or fully, from an inner surface 106 of the casing 101 across a diameter and / or length of the casing 101 and / or core 102. For example, Figures 19A, 19C-D illustrate a spacing component 1905 extending fully across the inner diameter of the casing, while Figure 19E illustrates a plurality of spacing components extending partially across an inner diameter of the casing. In another example illustrated in Figure 19B, a spacing component 1905 extends fully across a length of the casing. In some embodiments, the one or more spacing components extending from the inner surface of the casing may be: one or more planar surfaces; one or more rods; one or more tabs; one or more ledges; one or more wedges or a combination thereof. In some embodiments, the spacing component may be a webbed material.

[0168] In some embodiments, there is a void between the densifier and the casing. This void is one feature that could be responsible for the distance between the densifier and inner wall of the casing indicated by “c” in the equations herein.

[0169] In some embodiments, the one or more spacing components are shaped and / or dimensioned to engage one or more edges of the densifier. For example, one or more spacing components may be provided with one or more chamfered or bevelled edges to engage corresponding chamfered or bevelled edges of the densifier.

[0170] In some embodiments, the one or more spacing components are integrally formed with the casing. In some embodiments, the one or more spacing components are formed separately and affixed to the inner surface of the casing, for example, by welding or adhesive.

[0171] In some embodiments, the bolus 100 is absent a spacing component and the densifier or densifier matrix is fixed or retained in a position relative to the casing 101 and / or core 102 due to variations in the thickness and inner diameter of the casing, as illustrated, for example, in Figure 19F. The portion of the casing located towards the closed region 103 that houses the densifier or densifier matrix 104 is provided with a first thickness that is less than the thickness of the remainder of the casing 101 that houses the core 102. As will be appreciated, the thickness of the casing is proportional to the inner diameter of the casing such that the portion of the casing located towards the closed region that houses the densifier or densifier matrix has a greater diameter than the remainder of the casing that houses the core 102. This permits the densifier or densifier matrix to have a diameter that is greater than the diameter of the core such that it engages the portion of the casing having a greater thickness, thereby fixing or retaining the densifier or densifier matrix relative to the casing and / or core.

[0172] Closed region

[0173] A closed region is a region of the casing that was open when the casing was originally formed, and is closed at a later time. For example, the casing may be open when the core is added to the casing and the casing then closed to encompass the core thereby forming a closed region.

[0174] The closing region is the portion of the closing that is open when the casing is formed and at a later time closed to form the closed region. The closing region is optionally the full open portion of the casing (when closed this will result in a core fully enclosed in casing). The closing region is optionally only part of the open portion of the casing with another portion of the casing remaining open.

[0175] In some embodiments, the closed region is casing material joined by a closing means such as stitching or, for example, casing material that is melted and resolidified to create a join. In some embodiments, the closed region includes a cap that is connected to the casing material. The cap can be joined to the casing material by stitching or melting and resolidification to create a join.

[0176] In some embodiments, the closed region is a sealed region (i.e. a region that is irreversibly closed during manufacture to encapsulate the core in the casing). In some embodiments, the sealed region is generated through melting or soldering together one or more components of the casing. Preferably, the sealed region is generated through spin-welding. In some embodiments, the closed region is a fastened region (i.e. a region that is reversibly closed during manufacture to encapsulate the core in the casing). In some embodiments, the fastened region includes a thread retention means.

[0177] In some embodiments, the casing is closed by sealing the opening (or part of the opening). The casing comprises polymeric material. Sealing can be by adhesion such as gluing. However, it is preferred to melt and resolidify the edges of the polymer to form a strong join. This can be done by welding, such as spin welding. The process of spin welding involves generating heat by rotational friction to weld thermoplastic parts. The spin welder applies force axially while rotating relative to the bolus. The resulting friction generates heat that melts the casing. Once rotation stops, the casing cools and solidifies, forming a welded close. In preferred embodiments, the full casing is fully closed. This makes manufacture of the bolus more straightforward.

[0178] In some embodiments, the closing region includes previously separate portions of casing that have been melted and / or soldered together. In some embodiments, the closed region includes a cap that is connected to the casing material.

[0179] In some embodiments, the closed region is of the same composition throughout. In some embodiments, the closed region is of the same composition as the remainder of the casing. In some embodiments, the closed region does not include a feature to facilitate release of the active ingredient through the closed region at a rate greater than the remainder of the casing.

[0180] In some embodiments, the closed region has a lower release rate of active ingredient than the remainder of the casing when in use (ie upon administration). In some embodiments, the closed region has substantially the same release rate of active ingredient as the remainder of the casing.

[0181] In some embodiments, the densifier and / or the densifier matrix includes the densifier in a shape that substantially conforms to the shape of the closed region such that at least a portion of the densifier is configured to be substantially received by the closed region when the bolus is sealed. This embodiment provides an advantage of eliminating or reducing dead space within a bolus between the densifier and the closed region. Elimination or reduction of dead space enables overall reduction of size and / or length of the bolus. An example of this embodiment is depicted in Figure 16. In addition to eliminating dead space, a densifier that is configured to be substantially received by the closed region is also less likely to interfere with the closed region when the closed region is configured to be sealed with the rest of the casing through a manufacturing process such as, but not limited to, spin welding. This lack of or reduced interference between the densifier and the closed region during manufacturing in turn improves structural stability of the casing in use (ie during storage, transport and upon administration). In some embodiments, such interference or friction between the densifier and the closed region during manufacturing could lead to substantial weakening of the casing at least in the closed region. In some embodiments, and as depicted in Figure 14, the densifier and / or the densifier matrix includes the frustum-cylindrical densifier. As depicted by Figure 16, the frustum-shaped region of the frustum-cylindrical densifier conform substantially to the shape of the cap and therefore, the frustum-shaped region is configured to be received by the cap. In comparison, as shown in Figure 16, the substantially cylindrical densifier of Figure 9 is only partially received by the cap. This is because there are regions of the cap whose diameter is smaller than the diameter of the substantially cylindrical densifier. As a result, height of the top of the frustum-cylindrical densifier when measured from the bottom of the cap is lesser than height of the top of the substantially cylindrical densifier when measured the bottom of the cap. This implies that the substantially cylindrical densifier of Figure 16 occupies more space within a bolus than the frustum-cylindrical densifier of Figure 14.

[0182] Active ingredient

[0183] As used herein, an active ingredient is an ingredient which interacts with the biology of a living organism to exhibit one or more effects such as treatment or prevention of a condition, for example, inhibiting a metabolic process such as methanogenesis in relevant ruminal organisms when administered to the rumen of a ruminant in a therapeutically effective amount. In some embodiments, the active ingredient is a methane inhibitor. A “methane inhibitor” as used herein is an active agent, such as a compound or compound mixture, which is capable of inhibiting or reducing the production of methane gas in the rumen of a ruminant animal. In some embodiments, the methane inhibitor is a haloform, including a mixed haloform. Preferably the haloform is selected from chloroform, bromoform, iodoform, or combinations thereof; more preferably, bromoform.

[0184] Optionally, the active ingredient is liquid. Alternatively, the active ingredient is solid. In some embodiments, the active ingredient is volatile. Alternatively, the active ingredient is non-volatile. In some embodiments, the active ingredient is hydrophobic.

[0185] In some embodiments, the active ingredient has a molar mass of 100 to 600 g / mol, 100 to 500 g / mol, 100 to 400 g / mol, 100 to 300 g / mol, 200 to 500 g / mol, 200 to 400 g / mol or 200 to 300 g / mol. In some embodiments, the active ingredient has a logP of about 1 to about 4. In some embodiments, the active ingredient has a logP of 1.6 to 3.2.

[0186] In some embodiments, the active ingredient does not include protein or nucleic acid, for example, does not include a virus.

[0187] Optionally, the active ingredient or haloform is about 20 to about 90%, about 30 to about 80%, about 40 to about 80%, about 50 to about 70% or about 60% w / w of the core.

[0188] Hydrophobicity

[0189] In some embodiments, the densifier matrix includes a matrix material more hydrophobic than the at least one carrier. The skilled person will appreciate that hydrophobicity may be measured through analysis of water contact angles using a goniometer. In some embodiments, the difference in static water contact angle between the densifier matrix material and the at least one carrier is at least about 60°, at least about 50°, at least about 40°, at least about 30°, at least about 20°, at least about 15°, at least about 10°, or at least about 5° at 20 °C.

[0190] Ruminant

[0191] In some embodiments, the bolus is for, or suitable for, administration to the rumen of a ruminant animal. In some embodiments, the ruminant is bovine, ovine, caprine or cervine. In some embodiments, the ruminant is bovine. In some embodiments, the ruminant is ovine.

[0192] Bolus

[0193] A bolus is a type of pill, capsule or tablet used in veterinary medicine. The bolus is usually used for oral administration to the gastrointestinal tract of the animal. The bolus is swallowed but may be administered with the assistance of a bolus gun, several versions of which are commercially available. A bolus can be hard or of softer more malleable consistency. The shape of a bolus can vary but round, oblong or capsule shapes are common. The size of the bolus can vary as is suitable for administration to the relevant animal. The present disclosure contemplates boluses suitable for administration to ruminant animals. In a preferred embodiment, and as depicted in Figure 3, the bolus of the disclosure (100) includes a casing (101) that encapsulates or substantially encapsulates the core (102). The casing further comprises a closed region (103). The casing is optionally about 0.5 to about 2.0 mm thick, about 0.8 to about 2.0 mm thick, about 0.8 to about 1.8 mm thick, about 0.9 to about 1 .8 mm thick, about 1 .0 to about 1.8 mm thick, about 0.8 to about 1.5 mm thick, about 0.9 to about 1.5 mm thick, about 1.0 to about 1.5 mm thick or about 1.2 mm thick. The casing is optionally about 5 to about 15%, about 6 to about 12%, about 6 to about 10%, about 7 to about 15%, about 7 to about 12%, about 7 to about 10% or about 8% w / w of the bolus. The core is optionally about 20 to about 55%, about 25 to about 50%, about 30 to about 45%, about 35 to about 40% w / w or about 37% w / w of the bolus. The bolus further comprises a densifier (104), the densifier separates the closed region of the casing from the core. The densifier is optionally about 30 to about 75%, about 40 to about 70%, about 45 to about 65%, about 50 to about 60%, about 55% w / w of the bolus.

[0194] In some embodiments, the bolus comprises a therapeutically effective amount of an active ingredient and:

[0195] • about 5% to about 15% (w / w) casing;

[0196] • about 20 to about 55 (w / w) core; and

[0197] • about 30 to about 75 (w / w) densifier.

[0198] Release and duration

[0199] In some embodiments, the bolus of the disclosure comprises the methane inhibitor bromoform and is adapted to reach a maximum release rate of approximately 0.1 - approximately 0.5 g per day, and more preferably approximately 0.2 g per day. Such release rates may provide a sustained release of haloforms, such as bromoform. A bolus with such release rate is for instance suitable for use in cattle and sheep.

[0200] In some embodiments, the bolus may be adapted to exhibit a release rate of between 0.02 g and 2 g per day into the rumen, preferably a release rate of approximately 0.1 to 0.5g of bromoform per day. When a bolus exhibits such release rates for the methane inhibiting agent (e.g. a haloform, such as bromoform), this can reduce methane production. The rate of release of the methane inhibiting agent into the rumen may increase over time, i.e. the rate of release starts from zero on administration to the animal and increases to a maximum due to several factors. However, the foregoing should not be seen as limiting, and other release rates are envisaged as within the scope of the present disclosure.

[0201] In some embodiments, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 8 weeks after administration. In some embodiments, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 20 weeks after administration.

[0202] Diffusion testing

[0203] Diffusion testing is a common technique for assessing the nature of a dosage form in vitro. The diffusion test results are often correlated with in vivo performance of the dosage form and used for quality control testing to ensure consistent manufacture of the dosage form.

[0204] Diffusion of the haloform from boluses of the disclosure into the surrounding solution was tested in 1 L of a phosphate buffer at pH 6.5 (simulating rumen pH) and at 39 °C (simulating rumen temperature) over a period of months without agitation. Samples of the buffer were taken daily and analyzed for bromoform by GC-FID.

[0205] Diffusion testing has similarities to dissolution testing. Dissolution testing involves placing the dosage form in a liquid of specific pH and temperature, and with specific agitation and determining the time it takes for the active ingredient to release from the dosage form. There are standardised dissolution tests in the US and European Pharmacopoeias (USP & EP). See for example Chapter <711> of the USP. However, these dissolution tests are not suitable for measuring diffusion of the dosage forms of the present disclosure, at least due to the size and extended for the length of the boluses.

[0206] Methods of administration

[0207] In another aspect, the present disclosure provides a method of administering a methane inhibitor to a ruminant animal, the method including administering to the rumen of the ruminant animal a bolus in accordance with this disclosure. In another aspect, the present disclosure provides a method of reducing methane production in the rumen of a ruminant animal, the method including administering to the rumen of the ruminant animal a bolus in accordance with this disclosure.

[0208] In embodiments of the methods of the disclosure, the bolus administers haloform to the rumen of the ruminant animal for at least about 8 weeks after administration. Optionally, the bolus administers haloform to the rumen of the ruminant animal for at least about 20 weeks after administration.

[0209] In embodiments of the methods of the disclosure, following administration of the bolus the bolus sinks below the liquid surface or to the bottom of the rumen.

[0210] In embodiments of the methods of the disclosure, the bolus remains in the rumen following administration for at least about 8 weeks or at least about 20 weeks.

[0211] In embodiments of the methods of the disclosure, following release of the active ingredient the bolus degrades in the rumen. Optionally, the degradation is until the remnants of the bolus are of a size that can safely pass through the ruminant.

[0212] In some embodiments of the methods of the disclosure, the bolus of the disclosure comprises the methane inhibitor bromoform and reaches a maximum release rate of approximately 0.1 - approximately 0.5 g per day, and more preferably approximately 0.2 g per day.

[0213] In some embodiments, the bolus exhibits a release rate of between 0.02 g and 2 g per day into the rumen, preferably a release rate of approximately 0.1 to 0.5g of bromoform per day. The foregoing should not be seen as limiting, and other release rates are envisaged as within the scope of the present disclosure.

[0214] In some embodiments, the bolus exhibits near zero-order release kinetics. In some embodiments, the bolus exhibits near zero-order release kinetics 2 months, 4 months and / or 6 months following administration.

[0215] Methods of production

[0216] In yet another aspect, the present disclosure provides a method of making a bolus, the method including: selecting a core, a casing having a closing region, and a densifier; inserting the core into the casing , inserting a densifier into the casing; closing the closing region of the casing to encapsulate or substantially encapsulate the core in the casing, thereby forming a closed region; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier; wherein the densifier is between the core and the closed region of the casing.

[0217] This method may be used to prepare bolus dosage forms according to the present disclosure.

[0218] In some embodiments, inserting the core into the casing occurs prior to inserting the densifier into the casing. In some embodiments, inserting the densifier into the casing occurs prior to closing the closing region of the casing.

[0219] In some embodiments, closing the closing region comprises closing two sections of the casing together. Alternatively, the closing includes closing of a cap. For example, closing the closing region comprises attaching a cap to the closing region of the casing or closing a cap already attached to the casing over the core (optionally attaching to another portion of the closing region of the casing). In some embodiments, the closing is by sealing or stitching. Optionally, the closing includes soldering and / or spin welding.

[0220] In some embodiments, the closing region includes a means to close the casing and the casing is closed using the means to close. Optionally, the means to close the casing is a cap.

[0221] In some embodiments, following closing of the closing region a closed region is formed from previously separate portions of casing that have been melted and / or soldered together. A closed region is a region that is closed during manufacture to encapsulate the core in the casing. In some embodiments, the closing region is made of the same composition as the bulk casing. In some embodiments, the closing region is made of a different composition to the bulk casing. The skilled person will appreciate compatibility factors that will allow them to achieve closing of compositions different from one another, for instance, similarity in melting points for spin welding. In some embodiments that involve spin welding different compositions together, the melting point of the 2 compositions is within 10 °C or 5 °C of one another. Ideally, the 2 compositions should be able to form a homogeneous mixture or dispersion.

[0222] In some embodiments, the densifier is above room temperature when it is inserted in the casing. In some embodiments, at least a component of the densifier and / or densifier matrix is liquid when it is inserted in the casing.

[0223] In some embodiments, the casing is prepared by injection molding.

[0224] In some embodiments, the densifier and / or densifier matrix is in direct contact with the core. In some embodiments, the densifier and / or densifier matrix is in direct contact with the closed region. Preferably, the densifier is in direct contact with the core and the closed region. In some embodiments, the densifier and / or densifier matrix does not directly contact one or both of the core and the closed region (for instance, a further spacing component may be present preventing directing contact).

[0225] In some embodiments, the closing region includes a means to close the casing. In some embodiments, the means to close the casing is a cap. In some embodiments, the closing region includes previously separate portions of casing that are melted and / or soldered together.

[0226] Examples

[0227] The boluses and methods herein are described by the following illustrative and non-limiting examples.

[0228] Example 1 - Bolus preparation

[0229] Bolus Preparation 9A and Preparation 9B were prepared as follows.

[0230] 1. Preparation of the core matrix: a) Weigh the components as listed below in Table 1. b) Put the weighed EC into a mortar (the skilled person will appreciate that other mixing apparatus can also be used, particularly on an industrial scale). c) Add bromoform in small amounts and mix with a pestle. Repeat until a uniform paste is formed. d) Add HPMC in small amount to the EC / bromoform paste and mix with a pestle. Repeat until a uniform dough is formed.

[0231] 2. Preparation of the densifier matrix (although the densifier matrix was made separately for each bolus, the skilled person will appreciate that a quantity of densifier matrix suitable for numerous boluses can be prepared in a single instance and divided appropriately, particularly on an industrial scale) e) Melt the weighed wax in a beaker at 70 °C, measuring temperature using a hot plate. f) Add the weighed steel balls and allow them to equilibrate to 70 °C for 10 minutes. g) Reduce the temperature and equilibrate to 60 °C.

[0232] 3. Filling the core matrix and densifier matrix in the casing and sealing

[0233] Note: Casings were prepared separately by injection moulding. The skilled person will appreciate that other techniques are also suitable. h) Weigh out 60 g of the core matrix and gently fill up the casing making sure there are little to no air gaps. i) Pour the densifier matrix prepared in step 2 on top of the core matrix. j) Allow the system to cool down and seal the bolus. Sealing can be done by soldering or spin welding, with spin welding providing preferred robustness.

[0234] Table 1. List of components and their details in Preparation 9A and Preparation 9B

[0235] Example 2 - Bromoform release rate Variations of Preparation 9A were assessed for bromoform release rate under the diffusion assay conditions described in this disclosure. Specifically, in 1 L of a phosphate buffer at pH 6.5 and at 39 °C without agitation. These in vitro conditions are significantly less intense than in the rumen of a ruminant animal, where there is agitation and various debris present. The variations of Preparation 9A varied in terms of casing wall width, and the presence or absence of densifier matrix, as described below:

[0236] • Preparation 9Ai: PLA / PBAT 1.2 mm thickness with densifier matrix according to Table 1 present

[0237] • Preparation 9Aii: PLA / PBAT 1 .2 mm thickness without densifier present

[0238] • Preparation 9Aiii: PLA / PBAT 0.9 mm thickness with densifier matrix according to Table 1 present

[0239] The matrix and densifier composition and amounts remained constant. The casing composition remained constant, but the amount of casing varied to achieve the desired thickness and compensate for the loss of densifier.

[0240] The results are depicted in Figure 1. Preparation 9Ai that included the thicker casing walls and the densifier matrix provided improved performance over the equivalent Preparation 9Aii that did not include the densifier matrix. As depicted in Figure 1 , the Preparation 9Aii suffered from a greater and less controlled release of bromoform in the absence of a densifier. The assay of Preparation 9Aii was stopped before 60 days as the core matrix had swelled and broken the bolus cap, as shown in Figure 2. This issue was identified to be caused by an incorrectly manually sealed cap. Fluid ingress then caused the swelling. This difficulty is not expected where the seal between cap and casing is prepared correctly. In contrast, Preparation 9Ai still provided controlled release of bromoform up to at least 120 days, with the cap still fastened to the bolus. Similarly, Preparation 9Aiii still provided controlled release of bromoform up to at least 120 days, with the cap still fastened to the bolus. This is despite Preparation 9Aiii featuring a thinner casing than Preparation 9Aii.

[0241] Without wishing to be bound by theory, it is believed that positioning the densifier (particularly a densifier matrix less permeable to a haloform, such as bromoform, than the carrier matrix) between the carrier matrix and the closed region (e.g.: lid) decreases the amount of bromoform permeating, and thus weakening, the closed region. It is thought that this increases the robustness of the closed region and the robustness and reliability of the bolus overall, particularly over the heavily extended release periods that are desirable. While other solutions may be possible, such as by use of a stronger or a more robust cap that is more strongly fastened. This solution uses features already required for the bolus in an intelligent way to resolve the problem without needing to select a more expensive cap or reinforce the join between the cap and the rest of the casing, both of which are likely to increase the cost of the dosage form.

[0242] Example 3 - Bromoform release rate

[0243] Two boluses (100) - one with a densifier (104) comprising only SS shots (F-SS) and another with a densifier (104) comprising SS shots and paraffin wax (F-SS / W) were made. The rate of release of bromoform from these boluses (100) was measured to identify if the presence of the wax affected the bromoform release rate.

[0244] Each of the boluses (100), F-SS and F-SS / W, comprises a core (102) further comprising bromoform, EC-45 (Ethoxyl: 48-49.5; Chloride- <0.05%; Apparent Viscosity- 41-49 mPa.s; Dupont / EthoCel™) and HPMC. The core (102) weighs 60 g with bromoform:EC-45:HPMC in a ratio of 58.4:27.3:14.3. The densifier (104) of F-SS / W comprises 67 g of SS shots and 5 g of paraffin wax whereas the densifier (104) of F-SS comprises 72 g of SS-shots.

[0245] Table 2. Composition of core and densifier of boluses of Example 3 The casing (101) in Example 3 was prepared using injection molding from 90% polylactic acid (PLA) (Manufacturer - NatureWorks; Brand name- Ingeo™ Biopolymer 3251 D; Specific gravity- 1.24 Tensile strength- 62 MPa; average molecular weight - -145000 g / mole; D lactic acid- 1.2%) and 10% polybutylene adipate terephthalate (PBAT) (Manufacturer - Zhuhai kingfa Biomaterial Co, Brand name - Kingfa KB100 HF, average molecular weight - -80000 g / mole) blend (Zhuhai kingfa Biomaterial Co., Ltd / ECOPOND® Compostable Plastics G800 M10). The length of each bolus casing was 75 mm, diameter was 35 mm and thickness was 1.5 mm. The external surface of the casing is smooth and the ends rounded to avoid sharp edges. There are indents in both ends of the bolus as depicted in figures 16, 20 and 21. These indents are not considered important to the bolus design. There are no ribs or other reinforcements of the casing. The internal surface of the casing is also smooth. The cap was made of the same material in the same thickness as the casing and joined by spin welding, the join being very slightly thickened (under 0.2 mm increase).

[0246] For release rate testing, the prepared boluses (100) were kept in 1 L Schott bottles, containing 0.02 M phosphate buffer and were stored at 40 °C (±2 °C). The buffer was changed everyday except over weekends. Minimum 2 daily release data points were collected per week in all cases. Bromoform was quantified using GC-FID (Shimadzu, Nexus GC-2030). Briefly, in each case 8 g sample was collected using autopipette in 15 mL Falcon tubes. A weighing balance was employed for this purpose. To this, 2 mL of heptane (Analytical GO grade, Merck) was added to each Falcon tube as extraction solvent for bromoform. The Falcon tubes were capped, well mixed using a Vortex, and centrifuged at 4000 rpm for 15 minutes. 0.5 mL of heptane was recovered and loaded in GO vial. 200 pl of sample was injected using an autosampler and analysed using a ZB5HT 30 m capillary column using a temperature ramp of 30-300°C over 20 minutes, at 5 mL / min nitrogen gas flow, in splitless mode. Bromoform had a retention time of -5 minutes. Peak areas were compared to calibration standards made up in heptane to determine the mass of bromoform (mg) in the solution and correlated to quantify bromoform release per day in the 1 L buffer solution.

[0247] Referring now to Figure 4, the release rates of bromoform from the boluses (100) F-SS and F-SS / W are substantially the same. The only difference appears to occur after approximately 70 days of testing when the release rate of the bolus (100) F-SS appears slightly higher than the release rate of the bolus (100) F-SS / W.

[0248] Without wishing to be bound by theory, it is believed that the cause for the bolus (100) F-SS producing a higher release rate of bromoform compared to the bolus (100) F- SS / W is due to build up of vapour pressure from the bromoform inside the casing (101) of F-SS and / or the absorption of the bromoform by the wax in the densifier (104) of the F-SS / W bolus (100).

[0249] Example 4 - Bromoform release rate

[0250] Boluses (100) were prepared with densifier (104) comprising SS shots (F-SHOTS) or a solid densifier SS block (F-SD). All the other parameters were kept constant. The boluses were then placed in 1 L Schott bottles, containing 0.02 M phosphate buffer as described below. These bottles were stored at 40 °C (±2 °C) for daily release testing.

[0251] Preparation of the boluses:

[0252] Two different boluses were prepared with varying densifier composition (as shown in Table 3, replicates were prepared in each case). Briefly, bromoform (TBM) (Assay= 98%; Vynova; stabilized with ethanol) was added to ethyl cellulose (EC) (Ethoxyl: 48- 49.5; Chloride- <0.05%; Apparent Viscosity- 6-8 mPa.s; Dupont / EthoCel™) to form a sticky paste in a mortar and pestle. To this mass hydroxypropyl methyl cellulose (HPMC) (K100 M Premium; Methoxyl content- 19-24%; Hydroxypropyl content- 7-12%; Apparent Viscosity- 75000-140000 mPa.s; Dupont / Methocel™) was added in small aliquots followed by mixing. This process was repeated until all the HPMC was added, and a uniform dough / matrix was formed.

[0253] Table 3. Boluses prepared to investigate the effect of change in matrix of the densifier in term of bulk matrix (solid metal or SS shots).

[0254] Once, the TBM / EC / HPMC core matrix was prepared, 74g was loaded into the casing / housing. On top of the core matrix, densifier (SS shots only or SS block(cylindrical)) was added. The stainless-steel (SS) shots were 0.1-0.5 mm diameter of grade 304 from Taizhou Meanstar Hi-tech Materials Co. Ltd. The casing with the TBM / EC / HPMC matrix and densifier was then capped using a spin welding machine.

[0255] The housing was prepared using injection molding technic from 90% polylactic acid (PLA) (Manufacturer - NatureWorks; Brand name - Ingeo™ Biopolymer 3251 D; Specific gravity - 1.24 Tensile strength - 62 MPa; average molecular weight - -145000 g / mole; D lactic acid - 1.2%) and 10% polybutylene adipate terephthalate (PBAT) (Manufacturer- Zhuhai kingfa Biomaterial Co, Brand name - Kingfa KB100 HF, average molecular weight- -80000 g / mole) blend (Zhuhai kingfa Biomaterial Co., Ltd / ECOPOND® Compostable Plastics G800 M10). The length of each bolus casing was 75 mmm, diameter was 35 mm and thickness was 1 .5 mm. The shape and cap and joining were as described in Example 3.

[0256] Release testing:

[0257] As described in Example 3.

[0258] Result: As shown in Figure 5, there was no significant difference in the release profile of the two boluses over 40 days suggesting bulk nature (shots or solid block) likely did not affect the release profile. Nevertheless, as described in Example 3, subtle difference in release was observed after 40 days. Without being bound by theory, bromoform vapor pressure may build up over time in the head space, which may contribute to slightly higher release in case of bolus with SS shots over time potentially via additional diffusion in vapor phase.

[0259] Example 5 - Density of densifier matrix

[0260] Multiple embodiments of densifier matrices (104) comprising stainless steel shot (SS shot) of substantially 0.5 mm and a wax were made and their respective measured density values were compared to their respective theoretical density values.

[0261] 1. Preparation of densifier matrix a) Weigh the wax and SS shots as listed below in Table 4. b) Heat each mixture of wax and the SS shot until the wax is melted.

[0262] 2. Measurement density of densifier matrix a) Measure 9 ml of the melted wax and SS shot mixture (which forms the densifier matrix) b) Weigh the 9 ml of wax and SS shot mixture. c) Calculate the measured density value using the formula:

[0263] Weight of the wax and SS shot mixture Measured Density = — - - — - - - - -

[0264] Volume of the wax and SS shot mixture

[0265] 3. Calculation of theoretical density of the densifier matrix

[0266] Calculate theoretical density using the following equation:

[0267] Theoretical density mass of SS shots mass of SS shots + [I volume of the densifier matrix — density of wax] density of SS shots volume of the densifier matrix 4. Table 4. Comparison of measured density and the theoretical density of the densifier matrix

[0268] The differences in percentage between the theoretical and measured density values are subtle and within a range of 0.09% to 1.77%. One skilled in the art would appreciate that densifier of desired density may be achieved by varying the mass fraction of matrix material (e.g. wax) and densifier (e.g. SS shots).

[0269] Example 6 - Densifiers - variations of shape, size, weight and chamfer radius

[0270] Various embodiments of the densifier (104) with variations in shape, size, weight and chamfer radius are depicted in Figures 6 to 15. The densifiers (104), in the illustrated examples, were made of stainless-steel grade 316 (SS 316) material. The densifiers (104) were made for assembly with a casing (101) having an inner diameter (D) of 32 mm. Further details of the embodiments are given below in Table 5. Table 5: Details concerning various densifier embodiments The densifier (104) of Figure 6 is spherical in shape with a maximum diagonal length (c) equal to its diameter (d) of 27.98 mm. This value is less than the inner diameter (D) of the casing (101) which is 32 mm. The significant difference in the diameter (d) of the densifier (104) and the inner diameter (D) also leads to a large distance (c) value of 2.01 mm. Therefore, the densifier (104) of Figure 6 can potentially sink into the core (102) as well as not be retained in an initial location as a friction-fit between the inner walls of the casing (101) and the densifier (104) cannot be achieved. This was observed to be the case in the test results illustrated by Figure 20.

[0271] Three boluses (100), referred to as 9I-72, 9H-74a and 9H-74b, were prepared to assess change in position of spherical densifiers (104) as illustrated by Figure 6 in use. The boluses (100) 9I-72, 9H-74a and 9H-74b were made from a casing (101) of PLA and PBAT in a PLA:PBAT ratio of substantially 90:10. The casing is as described in Example 3. The core (102) comprised a core matrix of:

[0272] • bromoform (which is the substance to be administered),

[0273] • EC-7 (ethyl cellulose - viscosity grade 7 (Ethoxyl: 48-49.5;Chloride- <0.05%;Apparent Viscosity- 6-8 mPa.s; Dupont / EthoCelTM Standard 7 Premium)], and

[0274] • HPMC (K100 M Premium; Methoxyl content- 19-24%; Hydroxypropyl content- 7- 12%; Apparent Viscosity- 75000-140000 mPa.s; Dupont / Methocel™)

[0275] The bromoform:EC7:HPMC ratio was substantially 65:25:10. The core (102) of the bolus (100) 9I-72 weighed 72 g. The respective cores (102) of the boluses (100) 9H-74a and 9H-74b weighed 74 g. A densifier (104), such as the one depicted by Figure 6, was placed at an initial position of an end of the core (102) inside the casing (101) of each of the three boluses (100) 9I-72, 9H-74a and 9H-74b.

[0276] The three boluses (100), 9I-72, 9H-74a and 9H-74b, were cut open after a period (74 days) of testing (ie boluses were submerged in 1 L Schott bottles, containing 0.02 M phosphate buffer at 40 °C (±2 °C) with the densifier oriented at the top such that gravity acts to push the densifier into the core). As shown in Figure 20, the densifiers (104) had sunk into the core (102) and moved from an initial position of the end of the core (102).

[0277] The respective maximum diagonal lengths (c) of the densifiers (104) of Figures 7 to 12 were greater than the inner diameter (D) value of 32 mm. These densifiers (104) are configured not to sink into the core (102) in use. This was observed to be the case in the test results illustrated by Figure 19.

[0278] Two boluses (100), referred to as 9H-74A and 9H-74B, were prepared to assess change in position of densifiers (104) as illustrated by Figure 12 in use. Each bolus (100), 9H-74A and 9H-74B comprised:

[0279] • a casing made of PLA and PBAT with the PLA:PBAT ratio being substantially 90:10 and having the thickness, dimensions, shape, cap and join as described in Example 3;

[0280] • a core comprising bromoform, EC-7 and HPMC in a respective ratio of substantially 65: 25:10; and

[0281] • a densifier (104) such as the one depicted by Figure 12 placed at an initial position of an end of the core (102) in the casing (101).

[0282] The boluses (100), 9H-74A and 9H-74B, were cut open after a period of testing. 9H-74A was cut open after 88 days of testing and 9H-74B was cut open after 75 days of testing. In both cases, the densifiers (104) moved from an initial position near the cap (103) but had not sunk into the core (102) or altered their initial position at the end of the core (102). This is depicted by Figure 19.

[0283] The alteration of the position of the densifier (104) with respect to the core (102) was observed to impact the release rate of the substance and the structural integrity of the casing (101). Referring now to Figure 22 which depicts the release rate of the boluses (100) 9I-72, 9H-74a and 9H-74b and the release rate of the boluses (100) 9H-74A and 9H-74B in a water bath testing system.

[0284] The water bath testing system comprises a reservoir and a circulation system. The reservoir further comprises water in which the boluses (100) 9I-72, 9H-74a, 9H-74b, 9H- 74A and 9H-74B are submerged during testing. Further, the reservoir water is maintained at a temperature of 40 °C by a heater controlled by a proportional-integral-derivative (PID) controller. The circulation system comprises a pump, tubing and activated carbon filters. The pump is configured to circulate the water in the reservoir at regular intervals through the filters to remove the bromoform from the boluses (100), 9I-72, 9H-74a, 9H-74b, OH-

[0285] ST 74A and 9H-74B. The removal of bromoform from the reservoir’s water ensures substantially constant sink conditions in the reservoir water.

[0286] Release rate of bromoform is measured by removing each of the boluses (100), 9I-72, 9H-74a, 9H-74b, 9H-74A and 9H-74B, from the reservoir water, drying them, and measuring the weight. Weight loss of the boluses (100) is directly correlated to bromoform release. Although there may be some weight gained by each of the boluses (100), 9I-72, 9H-74a, 9H-74b, 9H-74A and 9H-74B, due to uptake of water by the casing (101), good correlation between weight loss and bromoform release has been observed once the rate of bromoform release is greater than the rate at which water is absorbed by the casing

[0287] (101). It is expected that changes in mass due to influx / efflux of other components is minimal.

[0288] The boluses (100) 9I-72, 9H-74a and 9H-74b were observed to release bromoform at a higher rate than the boluses (100) 9H-74A and 9H-74B. It may be noticed that all the boluses (100) showed a similar rate of release of bromoform initially. However, after approximately 20 days, the bromoform release rate of the boluses (100) 9I-72, 9H-74a and 9H-74b is higher than the bromoform release rate of the boluses (100) 9H-74A and 9H-74B. The average bromoform release rate of the boluses (100) 9I-72, 9H-74a and 9H- 74b is substantially between 200 mg / day to 150 mg / day over a period of 35 days from day-20 to day-55. In contrast, the average bromoform release rate of the boluses (100) 9H-74A and 9H-74B is substantially between 175 mg / day to 125 mg / day over a period of 35 days from day-20 to day-55. Further, the boluses (100) 9H-74A and 9H-74B have an average release rate of 175 mg / day to 100 mg / day over a period of 55 days from day-20 to day-75.

[0289] Without wishing to be bound by theory, it is believed that the increased bromoform release rate in boluses (100) with a densifier (104) substantially surrounded by the core

[0290] (102) is likely to be caused due to availability of a larger surface area of the casing (101) from which the bromoform may release. In comparison, the surface area of the casing

[0291] (101) in case of boluses (100) with the densifier (104) positioned at an end of the core

[0292] (102) is lesser.

[0293] The boluses (100) 9I-72, 9H-74a and 9H-74b were unable to be tested over a longer period unlike the boluses (100) 9H-74A and 9H-74B because the respective casings (101) of the boluses (100) 9I-72, 9H-74a and 9H-74b fractured sooner than the boluses (100) 9H-74A and 9H-74B. Once a bolus (100) fractures, the core (102) is exposed to the reservoir water, thereby making further testing of release of bromoform through the casing (101) impossible. The bolus (100) 9I-72 fractured after 56 days of testing. The bolus (100) 9H-74a fractured after 49 days of testing. The bolus (100) 9H- 74b fractured after 57 days of testing. In contrast, the bolus (100) 9H-74A fractured after 88 days of testing. And the bolus (100) 9H-74B fractured after 75 days of testing. Therefore, the boluses (100) 9I-72, 9H-74a and 9H-74b were observed to be structurally weaker than the boluses (100) 9H-74A and 9H-74B under the testing conditions employed. The skilled person will appreciate that a release period of days (eg less than 49 days) can still be useful for boluses of this disclosure.

[0294] The densifiers (104) illustrated by Figures 7 to 13 are cylindrical in shape. The densifier (104) of Figure 7 does not include a chamfered edge, i.e. , the chamfer radius is less than zero. The densifiers (104) of Figures 8 to 13 comprise a chamfered edge (105, as depicted in Figure 17) with a chamfer radius between 1 mm to 5 mm.

[0295] Figure 14 depicts a frustum-cylindrical densifier (104) comprising a frustumshaped region (111) and cylinder-shaped region (112). This frustum-cylindrical densifier (104) has a thickness of 16.16 mm. Figure 9 illustrates a cylindrical densifier (104) with a thickness of 16 mm. Although the thickness of the respective densifiers (104) of Figure 9 and Figure 14 are substantially the same, the height of the densifiers (104) when assembled with the closed region (103), i.e., the cap of the bolus (100), is different, as illustrated by Figure 16. The difference in height of the top of the densifier (104) of Figure 9 from the base of the cap (103) and the height of the top of the densifier (104) of Figure 14 from the base of the cap (103) is 4.33 mm. Therefore, the densifier of Figure 14 eliminates a dead space of 4.33 mm X TT X 16 mm X 16 mm which is equal to 3480.6 mm3. This volume is calculated using the following formula:

[0296] It will be understood what is disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the disclosure.

Claims

CLAIMS1. A bolus including: a core including at least one active ingredient and at least one carrier; a densifier; a casing that encapsulates or substantially encapsulates the core, wherein the casing includes a closed region; wherein the core is separated from the closed region and the densifier is between the core and the closed region; and wherein the bolus is formulated to remain in the rumen following administration.

2. The bolus of claim 1 , wherein the core does not contact the closed region.

3. The bolus of claim 1 or claim 2, wherein the densifier is between the closed region and the core.

4. The bolus of any one of claims 1 to 3, wherein the densifier has a specific position in the bolus, that is, in contact with the closed region and between the closed region and the core.

5. The bolus of any one of the preceding claims, wherein the densifier and / or densifier matrix directly contacts the core and the closed region.

6. The bolus of any one of the preceding claims, wherein the densifier is a densifier matrix comprising densifier and at least one veterinary acceptable excipient.

7. The bolus of any one of the preceding claims, wherein the densifier matrix includes a matrix material more hydrophobic than the at least one carrier.

8. The bolus of any one of the preceding claims, wherein the densifier matrix includes a wax.

9. The bolus of any one of the preceding claims, wherein the densifier matrix includes a matric material selected from the group consisting of castor wax, paraffinwax, stearic acid, microcrystalline wax, beeswax, stearyl alcohol, white wax, yellow wax, cetyl alcohol, cetyl esters wax, carnauba wax, ethyl vinyl acetate (EVA), and combinations thereof.

10. The bolus of any one of the preceding claims, wherein the densifier and / or densifier matrix includes metal.

11. The bolus of any one of the preceding claims, wherein a maximum diagonal length of the densifier or densifier matrix is greater than a maximum inner diameter of the casing.

12. The bolus of any one of the preceding claims, wherein densifier has at least a planar or flat surface facing the core.

13. The bolus of any one of the preceding claims, wherein densifier comprises or consists of metal.

14. The bolus of any one of the preceding claims, wherein densifier is cylindrical.

15. The bolus of any one of the preceding claims, wherein densifier includes metal, one or more metal components, or consists of metal or one or more metal components, or is a densifier matrix consisting of metal, or one or more metal components, and matrix material.

16. The bolus of any one of the preceding claims, wherein bolus further comprises a spacing component.

17. The bolus of any one of the preceding claims, wherein the spacing component is between the core and the densifier, such as a layer preventing contact between the core and densifier.

18. The bolus of any one of the preceding claims, wherein the densifier is fixed in its position in the bolus.

19. The bolus of any one of the preceding claims, wherein the densifier is fixed or retained in position by a spacing component.

20. The bolus of any one of the preceding claims, wherein the bolus comprises a spacing component having a dimensional value that substantially impedes or prevents the densifier from moving within the casing.

21. The bolus of any one of the preceding claims, wherein the spacing component extends, either partially or fully, from an inner surface of the casing across a diameter and / or length of the casing and / or core.

22. The bolus of any one of the preceding claims, wherein the spacing component is between the densifier and the casing such as a void between the densifier and the casing, preferably of air or nitrogen.

23. The bolus of any one of the preceding claims, wherein the spacing component is casing material, stainless steel, glass or halogenated polymer.

24. The bolus of any one of the preceding claims, wherein the carrier includes one or more materials selected from the list consisting of polycaprolactone (PCL), ethyl cellulose (EC), hydroxypropyl methylcellulose (HPMC), fumed silica / aerosil, castor wax, paraffin, stearic acid, microcrystalline wax, beeswax, polyethylene glycol (PEG), sodium starch glycolate, croscarmellose sodium, crospovidone, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate copolymer (PVP / VA), a polyacrylic acid and / or their co-polymer variants, polyisobutylene, ethyl vinyl acetate (EVA), a functional wax with a melting point less than about 120 °C, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes one or more biodegradable polymers selected from the list above, combinations thereof, combinations with talc thereof, and co-polymers thereof.

25. The bolus of any one of the preceding claims, wherein the carrier includes one or more biodegradable polymers.

26. The bolus of any one of the preceding claims, wherein the carrier includes one or more polymers selected from the list consisting of ethyl cellulose, hydroxypropyl methyl cellulose, combinations thereof, and co-polymers thereof.l. The bolus of any one of the preceding claims, wherein the casing includes one or more biodegradable polymers.

28. The bolus of any one of the preceding claims, wherein the casing includes one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly- D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof.

29. The bolus of any one of the preceding claims, wherein the casing includes one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof.

30. The bolus of any one of the preceding claims, wherein the active ingredient is a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof.

31. The bolus of any one of the preceding claims, wherein the carrier does not comprise hydrophobic fumed silica.

32. The bolus of any one of the preceding claims, wherein the carrier does not comprise a compound having the structure of formula (I) or (II),or a pharmaceutically acceptable salt thereof, wherein(1) each of Yi, Y2 and Y3 is independently selected from the group consisting of Br and Cl;(2) L is CH2, O, NH, or absent (preferably L is O or NH); and(3) R is an optionally substituted group selected from the group consisting of OH, C1- isalkyl , Ci-isalkoxy and Ci-salkyl-COOH; wherein if R is substituted, then it is substituted by one or more groups independently selected from the group consisting of Ci-salkyl , - OH, halogen, NH2, -COOH, -COCi-4alkyl, -COOCi-4alkyl, -NO2, and more particularly is substituted with one or more groups selected from the group consisting of Ci-2alkyl, - OH, halogen, NH2, -COOH, -COMe, and -COOMe.

33. The bolus of any one of the preceding claims, wherein the carrier does not comprise a compound having the structure of formula (la),I ’Y2— c — zY3 (la) or a pharmaceutically acceptable salt thereof, wherein each of Y1, Y2 and Y3 is independently selected from the group consisting of Br and Cl; andZ is:(1) a group that will be cleaved off the carbon atom shown in formula la, such that Z is replaced by a hydrogen atom when the composition is exposed to the environment inside the rumen of a ruminant animal; or(2) a group that will be cleaved off the carbon atom shown in formula la, such that Z is replaced by a hydrogen atom when compound la is contacted with a second activating compound that is comprised in said composition, wherein the second activating compound will come into contact with the compound la only when the composition is exposed to the environment inside the rumen of a ruminant animal.

34. The bolus of any one of the preceding claims, wherein the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 8 weeks after administration.

35. A method of administering a methane inhibitor to a ruminant animal, the method including administering to the rumen of the ruminant animal the bolus of any one of the preceding claims.

36. A method of reducing methane production in the rumen of a ruminant animal, the method including administering to the rumen of the ruminant animal the bolus of any one of claims 1 to 34.

37. A method of making a bolus, the method including: selecting a core, a casing having a closing region, and a densifier; inserting the core and densifier into the casing, closing the closing region of the casing to encapsulate or substantially encapsulates the core in the casing, thereby forming a closed region; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier.

38. The method of claim 37, wherein inserting the core into the casing occurs prior to inserting the densifier into the casing, optionally the spacing component is inserted (and optionally joined to the casing) after inserting the core into the casing and before inserting the densifier.

39. The method of claim 37, wherein inserting the densifier into the casing occurs prior to closing the closing region of the casing, optionally the spacing component is inserted (and optionally joined to the casing) after inserting the densifier into the casing and before inserting the core.

40. A method of making a bolus, the method including: selecting a core, a casing having a closing region and a densifier;inserting the core into the casing , inserting a densifier into the casing; closing the closing region of the casing to encapsulate or substantially encapsulates the core in the casing thereby forming a closed region; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier; wherein the densifier is between the core and the closed region of the casing.

41. The method of claim 40, wherein the closing includes closing of a cap.

42. The method of claim 40 or 41, wherein the bolus is according to any one of claims 1 to 34.

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