GB2124899A

GB2124899A - Improved rumen bolus

Info

Publication number: GB2124899A
Application number: GB08220512A
Authority: GB
Inventors: Cyril Francis Drake; Mary Tripp
Original assignee: Standard Telephone and Cables PLC
Current assignee: STC PLC
Priority date: 1982-07-15
Filing date: 1982-07-15
Publication date: 1984-02-29
Also published as: GB2125698A; NZ204879A; GB8318900D0; GB2125698B; AU1671283A

Abstract

A rumen bolus for administration to a ruminant animal comprises a tubular body containing or incorporating an active material. Tho tubular shape of the body provides greater retention in the rumen than a conventional solid bolus.

Description

SPECIFICATION Improved rumen bolus This invention relates to animal husbandry and in particulartodevicesforthe administration of medicamentsto animals.

Ruminant animals, e.g. cattle and sheep, may be provided with medicaments by the administration of a rumen bolus. The bolus containing the medicament is administered orally and is intended to lodge in the rumen for a period sufficient for release of an active material into the digestive system ofthe animal. A major problem experienced with this technique is that of lack of retention ofthe bolus in the rumen. In many cases the bolus is swept into the post rumen portion of the digestive system along with the rumen contents before sufficient time has elapsed for effective medication to take place. This is a particular problem where it is intended to supply a medicamentto an animal over an extended period.

Attempts have been madeto overcome this problem by weighting the bolus, e.g. with iron weights, to provide gravity retention. This technique is however relatively costly and it is of course undesirable to introduce relatively large quantities offree metal into an animal.

The object of the present invention is to overcome the disadvantages of the prior art by providing a rumen boluswith improved retention properties.

According to one aspect ofthe invention there is provided a tubular rumen bolus.

According to another aspect ofthe invention there is provided a rumen bolus for administration to an animal, said bolus comprising a wholly or partially solubletubularbody incorporating one or more active materials.

We have found thatthe retention of a tubular rumen bolus, i.e. a hollow body having open ends, in the rumen of a ruminant animal is significantly greater than that of a solid body of similar density. Thus, the use of atubular bolus obviatesthe needforthe provision of metallic weights to ensure retention in the rumen for a reasonable period.

Embodiments ofthe invention will now be described with reference to the accompanying drawings in which: Fig. lisa plan view of a tubular rumen bolus; Fig. 2 is a longitudinal sectional view of the bolus of Fig.1; and Fig. 3 is a cross-sectional view ofthe bolus of Fig.1.

Referring to the drawings the bolus comprises a hollowtubular body 11, typicallyof annularcross section, which body is advantageously made of a water soluble glass composition. The dimensions of the bolus are by no means critical, butfor maximum retention it is preferred thatthe wall thickness ofthe body should be significantly less than its radius. The preferred ratio of wall thickness to outside radius is from Advantageously the entire body is soluble in the rumen fluids and incorporates one or more active materials released by dissolution of the body. The configuration of the body is such that its surface area does not change significantly during dissolution both from the inner and outer surfaces. Thus the dissolution rate is substantially constant.

Typicallythe body material is a water soluble glass incorporating one or more active materials, e.g. trace elements, in oxide form. These trace elements are released by dissolution of the glass which may be of the a phosphate type. The dissolution rate ofthe glass is determined by its composition and may be controlled bytheincorporation offurtherglass modifying oxides in the glass. Thus,forexample,the addition of alkali metal oxide to the glass increases its dissolution ratewhilsttheaddition of alumina orferric oxide decreases the dissolution rate. The techniques of glass dissolution rate control are morefullydescribed in our published specification No.2,057,420 (C.F.

Drake 70).

Field trials have demonstrated that tubular boiuses 2.5cm in diameter, having a density of 2.4gaze and lengths of 3,5,7 and 9 cm are retained in unfistulated cattle for periods of at least 120 days thus demonstrat- ing the efficiency of the technique. Three soluble glass compositions were used for these trails. These are listed in the following table, all concentrations being expressed in mole percent.

Glass Batch MgO CaO Na2O CnO P205 1 15.8 - 41.2 - 43 2 - 26.6 26.9 - 46.4 3 - 0.7 21.9 33.4 44.0 Furthersuitable glass composition are described in our co-pending application Nos. 38222/78 (C. F. Drake 64); 49600/78 (C. F. Drake-M. Tripp 68-2; and 8025964 (C. F. Drake-M.Tripp 72-3).

A variety of trace elements may be incorporated in the glass for release at a controlled rate into the rumen of an animal. These elements include, but are not limited to, copper, selenium, boron, magnesium, iron, iodine, zinc, cobalt, manganese and molybdenum.

In a further application the hollow axis ofthe tubular body may be packed with a highly soluble material, e.g. an antibioticorananthelminaticcomposition,to provide additional medication priorto dissolution of the body.

The bolus may be made by a variety of methods.

The body may be cast, pressed, drawn or moulded.

Advantageously the body may be cast by the process described in our co-pending application No.

(J. R. Brocklehurst-V. Baker-C.T. Millikin 6-1-1).

1. Atubularrumen bolus.

2. A rumen bolus for administration to an animal, said bolus comprising a wholly or partially soluble tubular body incorporating one or more active materials.

3. A bolus as claimed in claim 1 or 2, and comprising a water soluble glass composition.

4. A bolus as claimed in claim 3, wherein said glass incorporates one or more trace elements in oxide The drawing(s) originally filed were informal and the print here reproduced is taken from a later filed formal copy.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improved rumen bolus This invention relates to animal husbandry and in particulartodevicesforthe administration of medicamentsto animals. Ruminant animals, e.g. cattle and sheep, may be provided with medicaments by the administration of a rumen bolus. The bolus containing the medicament is administered orally and is intended to lodge in the rumen for a period sufficient for release of an active material into the digestive system ofthe animal. A major problem experienced with this technique is that of lack of retention ofthe bolus in the rumen. In many cases the bolus is swept into the post rumen portion of the digestive system along with the rumen contents before sufficient time has elapsed for effective medication to take place. This is a particular problem where it is intended to supply a medicamentto an animal over an extended period. Attempts have been madeto overcome this problem by weighting the bolus, e.g. with iron weights, to provide gravity retention. This technique is however relatively costly and it is of course undesirable to introduce relatively large quantities offree metal into an animal. The object of the present invention is to overcome the disadvantages of the prior art by providing a rumen boluswith improved retention properties. According to one aspect ofthe invention there is provided a tubular rumen bolus. According to another aspect ofthe invention there is provided a rumen bolus for administration to an animal, said bolus comprising a wholly or partially solubletubularbody incorporating one or more active materials. We have found thatthe retention of a tubular rumen bolus, i.e. a hollow body having open ends, in the rumen of a ruminant animal is significantly greater than that of a solid body of similar density. Thus, the use of atubular bolus obviatesthe needforthe provision of metallic weights to ensure retention in the rumen for a reasonable period. Embodiments ofthe invention will now be described with reference to the accompanying drawings in which: Fig. lisa plan view of a tubular rumen bolus; Fig. 2 is a longitudinal sectional view of the bolus of Fig.1; and Fig. 3 is a cross-sectional view ofthe bolus of Fig.1. Referring to the drawings the bolus comprises a hollowtubular body 11, typicallyof annularcross section, which body is advantageously made of a water soluble glass composition. The dimensions of the bolus are by no means critical, butfor maximum retention it is preferred thatthe wall thickness ofthe body should be significantly less than its radius. The preferred ratio of wall thickness to outside radius is from Advantageously the entire body is soluble in the rumen fluids and incorporates one or more active materials released by dissolution of the body. The configuration of the body is such that its surface area does not change significantly during dissolution both from the inner and outer surfaces. Thus the dissolution rate is substantially constant. Typicallythe body material is a water soluble glass incorporating one or more active materials, e.g. trace elements, in oxide form. These trace elements are released by dissolution of the glass which may be of the a phosphate type. The dissolution rate ofthe glass is determined by its composition and may be controlled bytheincorporation offurtherglass modifying oxides in the glass. Thus,forexample,the addition of alkali metal oxide to the glass increases its dissolution ratewhilsttheaddition of alumina orferric oxide decreases the dissolution rate. The techniques of glass dissolution rate control are morefullydescribed in our published specification No.2,057,420 (C.F. Drake 70). Field trials have demonstrated that tubular boiuses 2.5cm in diameter, having a density of 2.4gaze and lengths of 3,5,7 and 9 cm are retained in unfistulated cattle for periods of at least 120 days thus demonstrat- ing the efficiency of the technique. Three soluble glass compositions were used for these trails. These are listed in the following table, all concentrations being expressed in mole percent. Glass Batch MgO CaO Na2O CnO P205 1 15.8 - 41.2 - 43 2 - 26.6 26.9 - 46.4 3 - 0.7 21.9 33.4 44.0 Furthersuitable glass composition are described in our co-pending application Nos. 38222/78 (C. F. Drake 64); 49600/78 (C. F. Drake-M. Tripp 68-2; and 8025964 (C. F. Drake-M.Tripp 72-3). A variety of trace elements may be incorporated in the glass for release at a controlled rate into the rumen of an animal. These elements include, but are not limited to, copper, selenium, boron, magnesium, iron, iodine, zinc, cobalt, manganese and molybdenum. In a further application the hollow axis ofthe tubular body may be packed with a highly soluble material, e.g. an antibioticorananthelminaticcomposition,to provide additional medication priorto dissolution of the body. The bolus may be made by a variety of methods. The body may be cast, pressed, drawn or moulded. Advantageously the body may be cast by the process described in our co-pending application No. (J. R. Brocklehurst-V. Baker-C.T. Millikin 6-1-1). CLAIMS

1. Atubularrumen bolus.

form.

5. A bolus as claimed in claim 4, wherein said glass incorporating copper, selenium, boron, magnesium, iron, iodine, zinc, cobalt, manganese, molybdenum or mixtures thereof.

6. A bolus as claimed in claim 3 or4, wherein said glass comprises a phosphate glass.

7. A bolus as claimed in any one of claims 1 to 7 and comprising a plurality of water soluble glass compositions.

8. A bolus as claimed in any one of claims 1 to 7, wherein the ratio of the wall thickness to the external ratios is from to

9. A bolus as claimed in any one of claims 1 to 8 and containing a medicament having a relatively high solubility.

10. A rumen bolus substantially as described herein with reference to the accompanying drawings.

11. A method of treating an animal comprising administering to the animal a tubular rumen bolus as claimed in any one of claims 1 to 10.