Apparatus and method for coating a material

Abstract

The invention generally provides a method of coating a material, the method including the following steps: (a) forming a generally elongate coating structure ( 15 ), the coating structure having an internal cavity ( 17 ) extending at least substantially along its length, and wherein the internal cavity of the coating structure is capable of receiving a core material ( 21 ); (b) inserting a core material ( 21 ) into the internal cavity ( 17 ) of the coating structure ( 15 ); (c) compressing the coating structure at a first location ( 44 ) along its length so as generally to form a seal at that location; and (d) compressing the coating structure at a second location along its length ( 45 ).

The claims defining the invention are as follows:  
     
         1 . A method of producing a delivery device for the controlled release of a bioactive substance, comprising the following steps: 
 (a) forming a generally elongate coating structure to coat a core material containing the bioactive substance, the coating structure having an internal cavity extending at least substantially along its length, and wherein the internal cavity of the coating structure is capable of receiving a core material:    (b) inserting the core material into the internal cavity of the coating structure;    (c) compressing the coating structure at a first location along its length so as generally to form a seal at that location; and    (d) compressing the coating structure at a second location along its length.    
     
     
         2 . A method as claimed in  claim 1 , in which the coating structure is formed by extrusion from an extrusion means.  
     
     
         3 . A method as claimed in either of claims  1  or  2 , in which the coating structure is formed from a pharmaceutically or veterinarily acceptable polymeric material.  
     
     
         4 . A method as claimed in any of the preceding claims, in which the coating structure is formed as a single layer.  
     
     
         5 . A method as claimed in any one of  claim 1  to  3 , in which the coating structure comprises two or more layers.  
     
     
         6 . A method as claimed in  claim 5 , in which the two or more layers of the coating structure are layers of the same material.  
     
     
         7 . A method as claimed in  claim 5 , in which the two or more layers of the coating structure are layers of two or more different materials.  
     
     
         8 . A method as claimed in  claim 3 , in which the pharmaceutically or veterinarily acceptable polymeric material is selected from the group consisting of: 
 (a) polylactide co-glycolide polymers;    (b) polyesters;    (c) polysaccharides;    (d) polyamides;    (e) poly (amino acids);    (f) poly (ortho esters);    (g) polyanhydrides;    (h) polyphosphoesters;    (i) polymers formed through combinations of chemical bonds;    or combinations of two or more of (a) to (i).    
     
     
         9 . A method as claimed in  claim 8 , in which the polymers of group (i) comprise: 
 (i) pseudo-peptides;    (ii) poly (phosphoester-urethanes);    (iii) polydepsipeptides    or combinations of two or more of groups (i) to (ii).    
     
     
         10 . A method as claimed in any of the preceding claims, in which the core structure comprises: 
 (a) a tablet;    (b) a gel;    (c) a paste;    (d) granules;    (e) powder;    (f) a fluid; or    combinations of two or more of (a) to (e).    
     
     
         11 . A method as claimed in any of the preceding claims, in which the core material comprises: 
 (a) a bioactive substance selected from the group consisting of: 
 (i) natural, synthetic or recombinant pharmacological agents;  
 (ii) food additives;  
 (iii) food supplements;  
 (iv) antigens;  
 (v) antibodies;  
 (vi) cytokines;  
 (vii) growth promotants;  
 (viii) hormones;  
 (ix) vaccines;  
 (x) cancer cell inhibitory agents;  
 (xi) immuno-suppressants;  
 (xii) immuno-stimulants;  
 (xiii) antimicrobial agents;  
 (xiv) anti-viral agents;  
 (xv) vitamins;  
 (xvi) minerals;  
 (xvii) organic nutrients;  
 (xviii) inorganic nutrients: or  
 combinations of two or more of the aforegoing; and  
   (b) optionally, pharmaceutically or veterinarily acceptable carriers and/or excipients.    
     
     
         12 . A method as claimed in any of the preceding claims, in which the step of compressing the coating structure at the first location along its length so as generally to form a seal at that location comprises the step of bringing two or more mutually opposed surfaces of the coating structure into contact with one another, so as generally to form a seal at that location.  
     
     
         13 . A method as claimed in  claim 12 , in which the step of compressing the coating structure at the first location along its length involves cutting the coating structure at that location.  
     
     
         14 . A method as claimed in any of the preceding claims, in which the step of compressing the coating structure at the second location along its length comprises the step of bringing two or more mutually opposed surfaces of the coating structure together, so as to form a seal at that location.  
     
     
         15 . A method as claimed in any of  claims 1  to  13 , in which the step of compressing the coating structure at the second location does not give rise to the formation of a seal at that location.  
     
     
         16 . A method as claimed in either of claims  14  or  15 , in which the step of compressing the coating structure at the second location comprises cutting the coating structure at that location.  
     
     
         17 . A method as claimed in  claim 14 , whereby a generally sealed container is formed.  
     
     
         18 . A method as claimed in either of claims  15  or  16 , whereby a container is formed which is generally sealed at one of two mutually opposed ends thereof, but not at its other end.  
     
     
         19 . A method as claimed in any of the preceding claims, in which steps (a) to (d) of  claim 1  are repeated along the length of the coating structure, so as to produce a plurality of coated structures in the form of controlled release delivery devices for a bioactive substance.  
     
     
         20 . A method as claimed in  claim 19 , in which the method additionally comprises automation means to automate the repeated performance of the method along the length of the coating structure.  
     
     
         21 . A controlled release delivery device for a bioactive substance produced by a method as claimed in any of  claims 1  to  20 .  
     
     
         22 . A controlled release delivery device for a bioactive substance as claimed in  claim 21 , in which the device generally takes the form of a coated capsule or tablet.  
     
     
         23 . An apparatus for producing a controlled release delivery device for a bioactive substance, comprising: 
 (a) means for forming a generally elongate coating structure to coat a core material containing a bioactive substance, and wherein the coating structure has an internal cavity extending at least substantially along its length capable of receiving the core material therein;    (b) means for inserting the core material into the internal cavity of the coating structure;    (c) means for compressing the coating structure at a first location along its length; and    (d) means for compressing the coating structure at a second location along its length.    
     
     
         24 . An apparatus as claimed in  claim 23 , in which the means (a) are extrusion means.  
     
     
         25 . An apparatus as claimed in  claim 23 , in which the means (a) are means for extruding the coating structure in the form of two or more layers.  
     
     
         26 . An apparatus as claimed in either of claims  23  or  24 , in which the means for compressing the coating structure at the first location along its length are means which result in two or more opposed surfaces of the coating structure being brought together, so as thereby generally to form a seal at that location.  
     
     
         27 . An apparatus as claimed in  claim 26 , in which the means for compressing the coating structure at the first location are cutting means.  
     
     
         28 . An apparatus as claimed in any one of  claims 23  to  26 , in which the means for compressing the coating structure at the second location are means which do not form a seal at that location.  
     
     
         29 . An apparatus as claimed in any one of  claims 23  to  26  in which the means for compressing the coating structure at the second location are means for forming a seal at that location.  
     
     
         30 . An apparatus as claimed in any one of  claims 23  to  29 , in which the apparatus is capable of repeated operation along the length of the coating structure.  
     
     
         31 . An apparatus as claimed in claim  30 , in which automation means are provided to automate the production of controlled release delivery devices in accordance with the method of  claim 1.