Extended release tablet and method for making and using same

Abstract

Provided are cap layer compositions and base layer compositions, providing quick and extended release of an active ingredient, respectively, when placed in water. Further provided are dual release compositions including a base composition and a cap composition. The base composition may include a plaster and an active agent, and it may further include at least one of a water-soluble binder, a non-water-soluble binder, and a lubricant. The cap composition may include a plaster and an active agent, and it may further include at least one of a disintegrating agent, a non-water-soluble binder, and a lubricant. The compositions may be heated and mixed and formed into a tablet. Further provided are methods of making the compositions. Further provided are methods of controlling or eliminating pests and methods of increasing the potability of water. The compositions are effective for controlling or eliminating pests such as mosquitoes when applied at an application site.

We claim: 
     
         1 . A method for forming a composition comprising mixing without adding water at least one active agent, a plaster, and a binder, wherein the composition provides an extended release of the active agent over a period of at least 30 days when placed in water. 
     
     
         2 . The method of  claim 1 , the method further comprising heating during the mixing step. 
     
     
         3 . The method of  claim 1 , wherein mixing without adding water comprises dry-blending. 
     
     
         4 . The method of  claim 1 , wherein the binder comprises a water-soluble binder. 
     
     
         5 . The method of  claim 4 , wherein the water-soluble binder comprises polyethylene glycol. 
     
     
         6 . The method of  claim 4 , wherein the composition further comprises at least one additional component selected from a non-water-soluble binder and a lubricant. 
     
     
         7 . The method of  claim 6 , wherein the plaster comprises Plaster of Paris, the water-soluble binder comprises polyethylene glycol, the non-water-soluble binder comprises dicalcium phosphate dehydrate, the lubricant comprises magnesium stearate, and the active agent comprises at least one of a pesticide, insecticide, herbicide, fungicide, nematicide, acaricide, bactericide, rodenticide, miticide, algicide, germicide, repellant, and nutrient. 
     
     
         8 . The method of  claim 6 , wherein the active agent is present in an amount of about 0.01-50% wt, the plaster is present in an amount of about 40-90% wt, the water-soluble binder is present in an amount of about 5-50% wt, the non-water-soluble binder is present in an amount of about 0-30% wt, and the lubricant is present in an amount of about 0-1.5% wt. 
     
     
         9 . A method for forming a composition comprising mixing without water at least one active agent, a plaster, and a binder, wherein the composition provides a quick release of the active agent over a period of less than 10 minutes when placed in water. 
     
     
         10 . The method of  claim 9 , the method further comprising heating during the mixing step. 
     
     
         11 . The method of  claim 9 , wherein mixing without adding water comprises dry-blending. 
     
     
         12 . The method of  claim 9 , wherein the binder comprises a non-water-soluble binder. 
     
     
         13 . The method of  claim 9 , wherein the active agent comprises at least one of a pesticide, insecticide, herbicide, fungicide, nematicide, acaricide, bactericide, rodenticide, miticide, algicide, germicide, repellant, and nutrient. 
     
     
         14 . The method of  claim 12 , wherein the composition further comprises at least one additional component selected from a disintegrating agent, a water-soluble binder, and a lubricant. 
     
     
         15 . The method of  claim 14 , wherein the disintegrating agent comprises an effervescent. 
     
     
         16 . The method of  claim 15 , wherein the plaster comprises Plaster of Paris, the water-soluble binder comprises polyethylene glycol, the non-water-soluble binder comprises dicalcium phosphate dehydrate, the lubricant comprises magnesium stearate, and the disintegrating agent comprises at least one of citric acid and sodium bicarbonate or combinations thereof. 
     
     
         17 . The method of  claim 14 , wherein the active agent is present in an amount of about 0.01-30% wt, the plaster is present in an amount of about 0-40% wt, the disintegrating agent is present in an amount of about 20-80% wt, and the non-water-soluble binder is present in an amount of about 2-40% wt. 
     
     
         18 . A method of making an extended release solid matrix, the method comprising:
 a) mixing at least one active agent, a plaster, and a binder to form a mixture; and   b) heating the mixture at about 40° C. to about 75° C.   
     
     
         19 . The method of  claim 18 , wherein the mixture of step (b) is pliable. 
     
     
         20 . The method of  claim 18 , the method further comprising applying a mechanical force to the mixture to form granules; and compressing the granules into a tablet. 
     
     
         21 . The method of  claim 18 , the method further comprising:
 c) cooling the mixture;   d) breaking up the cooled mixture into granules; and   e) compressing the granules into a tablet.   
     
     
         22 . The method of  claim 21 , wherein step (d) is performed by forcing the cooled mixture through an oscillating granulator. 
     
     
         23 . The method of  claim 21 , wherein the tablet is produced by a dry granulation process. 
     
     
         24 . The method of  claim 21 , wherein a pressure of 5,000 to 30,000 pounds is applied to the granules in step (e). 
     
     
         25 . The method of  claim 21 , the method further comprising screening the granules for a particle size from about −20 mesh to about +60 mesh before step (e). 
     
     
         26 . The method of  claim 18 , the method further comprising:
 c) forcing the mixture through an extruder and cooling to form cooled extrudates;   d) breaking up the cooled extrudates into granules; and   e) compressing the granules into a tablet.   
     
     
         27 . The method of  claim 26 , wherein a pressure of 5,000 to 30,000 pounds is applied to the granules in step (e). 
     
     
         28 . The method of  claim 26 , the method further comprising screening the granules for a particle size from about −20 mesh to about +60 mesh before step (e).