Bolus

Abstract

The present invention relates to a bolus for administration to a ruminant by deposition into its rumen, wherein the bolus has a construction including: a) a casing; b) a core inside the casing wherein the core is formed from at least two tablets; and, is characterised in that a permanently amorphous substance at least partially coats one or more of the tablet or tablets. A method of forming such a bolus is also claimed.

1 . A bolus for administration to a ruminant by deposition into its rumen, the bolus having a construction including:
 a casing;   b) a core inside the casing wherein the core is formed from at least two tablets; and,   
       characterised in that a permanently amorphous substance at least partially coats one or more of the tablet or tablets. 
     
     
         2 . A bolus as claimed in  claim 1  wherein the permanently amorphous substance is an oil based substance. 
     
     
         3 . A bolus as claimed in  claim 1  wherein the permanently amorphous substance is petroleum jelly. 
     
     
         4 . A bolus as claimed in  claim 1  wherein the permanently amorphous substance is liquid paraffin. 
     
     
         5 . A bolus as claimed in  claim 1  wherein the casing is coated with a water impermeable material. 
     
     
         6 . A bolus as claimed in  claim 5  wherein the water impermeable material is plastics material. 
     
     
         7 . A bolus as claimed in  claim 6  wherein the plastics material is in the form of a series of intermeshed plastic rings. 
     
     
         8 . A bolus as claimed in  claim 7  wherein the rings are intermeshed using a tongue and groove joint between rings. 
     
     
         9 . A bolus as claimed in  claim 1  wherein the casing is a tubular shape with an approximately circular cross-section. 
     
     
         10 . A bolus as claimed in  claim 1  wherein the casing is an alloy casing. 
     
     
         11 . A bolus as claimed in  claim 10  wherein the tablets of the core contain electrically conductive material lower in the electrochemical series than the constituents of the alloy casing. 
     
     
         12 . A bolus as claimed in  claim 11  wherein the electrically conductive material of the core is graphite. 
     
     
         13 . A bolus as claimed in  claim 10  wherein the alloy casing is magnesium based. 
     
     
         14 . A bolus as claimed in  claim 13  wherein the magnesium forms approximately 70 to 98% of the alloy casing. 
     
     
         15 . A method of forming a bolus including a casing and a core containing tablets for delivery of an active agent or agents to the rumen of an animal wherein the method includes the steps of:
 (a) producing a tablet or tablets containing active agent or agents;   (b) at least partially coating one or more of the tablets from step (a) with at least permanently amorphous substance;   (c) packing at least two tablets into a casing to form a bolus wherein at least one of the tablets packed into the casing is produced from step (b).   
     
     
         16 . A method of forming a bolus as claimed in  claim 15  wherein the method includes an additional step of:
 (d) coating the casing with an water impermeable material with either one or both ends of the bolus not covered in water impermeable material. 
 
     
     
         17 - 18 . (canceled)