Process for making gel films

Abstract

The present invention is directed to a process for making homogeneous, thermoreversible gel films comprising the steps of: (i) heating, hydrating, mixing, solubilizing, and, optionally, de-aerating a high solids, low moisture film forming composition in an apparatus providing sufficient shear, temperature and residence time to form a homogeneous molten composition, wherein the temperature is at or above the solubilizing temperature of said composition; (ii) feeding the molten composition into at least one of a mixer, pump or devolatilizer; and (iii) cooling the homogeneous molten composition at or below its gelling temperature to form said gel films. The present invention is also directed to various products made from such films, such as the gel films themselves, soft capsules, solid dosage forms and delivery systems.

1 . A process for making homogeneous, thermoreversible gel films comprising the steps of: 
 (i) heating, hydrating, mixing, solubilizing, and, optionally, de-aerating a film forming composition in an apparatus providing sufficient shear, temperature and residence time to form a homogeneous molten composition, wherein said temperature is at or above the solubilizing temperature of said composition;    (ii) feeding said molten composition into at least one of a mixer or devolatilizer; and    (iii) cooling said homogeneous molten composition at or below its gelling temperature to form said gel films.    
     
     
         2 . The process of  claim 1 , wherein said film forming composition comprises at least one hydrocolloid film former and optionally a plasticizer, bulking agent, pH control agent and second film former.  
     
     
         3 . The process of  claim 1 , wherein said apparatus is a Ross mixer, Stephan processor, extruder, jet cooker or fluid mixing apparatus.  
     
     
         4 . The process of  claim 1 , wherein said molten composition is at least 50% solids.  
     
     
         5 . The process of  claim 1 , wherein said molten composition is at least 60% solids.  
     
     
         6 . The process of  claim 1 , wherein said molten composition is at least 70% solids.  
     
     
         7 . The process of  claim 1 , wherein said molten composition is at least 80% solids.  
     
     
         8 . The process of  claim 1 , wherein said molten composition is at least 90% solids.  
     
     
         9 . The process of  claim 1 , wherein said gel film has a break force of at least 1,000 grams.  
     
     
         10 . The process of claim,  1  wherein said gel film has a break force strength of at least 2,500 grams.  
     
     
         11 . The process of  claim 1 , wherein said gel film has a break force strength of at least 4,000 grams.  
     
     
         12 . The process of  claim 1 , wherein said gel film has a break force strength of at least 5,000 grams.  
     
     
         13 . The process of  claim 1 , wherein said gel film has a break force strength of at least 6,000 grams.  
     
     
         14 . (canceled)  
     
     
         15 . The process of  claim 2 , wherein said hydrocolloid is at least one member selected from the group consisting of a carrageenan, alginate, glucomannan or galactomannan, said plasticizer is at least one member selected from the group consisting of glycerin, sorbitol, maltitol, lactitol, and polyalkylene glycols; said second film former is at least one member selected from the group consisting of a starch, starch derivative, starch hydrozylate, cellulose gum, hydrocolloid, an alkylcellulose ether and a modified alkyl cellulose ether; and said bulking agent is at least one member selected from the group consisting of microcrystalline cellulose, microcrystalline starch, starch, starch derivatives, insulin, and starch hydrozylates.  
     
     
         16 . The process of  claim 15 , wherein said carrageenan is at least one member selected from the group consisting of iota carrageenan, kappa carrageenan and kappa-2 carrageenan; said alginate is propylene glycol alginate, said glucomannan is konjac and said galactomannan is guar gum.  
     
     
         17 . The process of  claim 1 , wherein said solubilizing temperature is greater than the boiling point of the homogeneous molten composition at atmospheric pressure and said heating, hydrating, mixing and solubilizing is conducted above atmospheric pressure.  
     
     
         18 . The process of  claim 1 , wherein said devolatilization is conducted in an extruder.  
     
     
         19 . The process of  claim 1 , wherein said molten composition is fed directly into said mixer, deareated, depressurized and pumped prior to cooling to or below the molten composition's gelling temperature.  
     
     
         20 . A homogeneous, thermoreversible, high solids, low moisture film made from the process of  claim 1 .  
     
     
         21 . A process for making soft capsules comprising the steps of: 
 (i) heating, hydrating, mixing, solubilizing and, optionally, de-aerating a high solids, low moisture film forming composition in an apparatus providing sufficient shear, temperature and residence time to form a homogeneous molten composition, wherein said temperature is at or above the solubilizing temperature of said composition;    (ii) feeding said molten composition into at least one of a mixer or devolatilizer;    (iii) cooling said molten composition to or below the gelling temperature of the molten composition to form a homogeneous, thermoreversible gel film; and    (iii) making soft capsules from said gel film.    
     
     
         22 . The process of  claim 21 , wherein said film forming composition comprises at least one hydrocolloid and optionally a plasticizer, bulking agent a pH control agent and second film former.  
     
     
         23 . The process of  claim 21 , wherein said apparatus is a Ross mixer, extruder, Stephan processor, jet cooker or fluid mixing apparatus.  
     
     
         24 . The process of  claim 21 , wherein said molten composition is at least 50% solids.  
     
     
         25 . The process of  claim 21 , wherein said molten composition is at least 60% solids.  
     
     
         26 . The process of  claim 21 , wherein said molten composition is at least 70% solids.  
     
     
         27 . The process of  claim 21 , wherein said molten composition is at least 80% solids.  
     
     
         28 . The process of  claim 21 , wherein said molten composition is at least 90% solids.  
     
     
         29 . The process of  claim 21 , wherein said gel film has a break force of at least 1,000 grams.  
     
     
         30 . The process of  claim 21 , wherein said gel film has a break force strength of at least 2,500 grams.  
     
     
         31 . The process of  claim 21 , wherein said gel film has a break force strength of at least 4,000 grams.  
     
     
         32 . The process of  claim 21 , wherein said gel film has a break force strength of at least 5,000 grams.  
     
     
         33 . The process of  claim 21 , wherein said gel film has a break force strength of at least 6,000 grams.  
     
     
         34 . The process of  claim 21 , wherein said molten composition is fed into an extruder having at least one of a pump, mixer and devolatilizer.  
     
     
         35 . The process of  claim 22 , wherein said hydrocolloid is at least one member selected from the group consisting of a carrageenan, alginate, glucomannan or galactomannan, said plasticizer is at least one member selected from the group consisting of glycerin, sorbitol, maltitol, lactitol, and polyalkylene glycols; said second film former is at least one member selected from the group consisting of a starch, starch derivative, starch hydrozylate, cellulose gum, kappa carrageenan; iota carrageenan, kappa-2 carrageenan, alginates, propylene glycol alginate, polymannan gums, pullulan, dextran, gellan, pectin, an alkylcellulose ether and a modified alkyl cellulose ether; and said bulking agent is at least one member selected from the group consisting of microcrystalline cellulose, microcrystalline starch, starch, starch derivatives, insulin, and starch hydrozylates.  
     
     
         36 . The process of  claim 35 , wherein said carrageenan is at least one member selected from the group consisting of iota carrageenan, kappa carrageenan and kappa-2 carrageenan; said alginate is propylene glycol alginate, said glucomannan is konjac and said galactomannan is guar gum.  
     
     
         37 . The process of  claim 21 , wherein said solubilizing temperature is greater than the boiling point of the homogeneous molten composition at atmospheric pressure and said heating, hydrating, mixing and solubilizing is conducted above atmospheric pressure.  
     
     
         38 . The process of  claim 21 , wherein said devolatilization is conducted in an extruder.  
     
     
         39 . The process of  claim 21 , wherein said molten composition is fed directly into said mixer, deareated, depressurized and pumped prior to cooling to or below the molten composition's gelling temperature.  
     
     
         40 . Soft capsules made by the process of  claim 21 .  
     
     
         41 . A process for making a solid dosage form comprising a fill material encapsulated by a homogeneous, thermoreversible gel film comprising the steps of: 
 (i) preparing the homogeneous, thermoreversible gel film in accordance with the process of  claim 1;  and    (ii) encapsulating said fill material in said gel film.    
     
     
         42 . The process of  claim 41 , wherein said fill material is a powder, tablet, caplet, microcapsule or capsule.  
     
     
         43 . The solid form of  claim 41 , wherein said solid form is a hard capsule.  
     
     
         44 . A process for preparing a homogeneous gel film delivery system comprising an active substance and a homogeneous, thermoreversible gel film, comprising the steps of: 
 (i) preparing the molten composition of  claim 1;  and    (ii) adding an effective amount of an active substance prior to or after formation of the molten compositions; and    (iii) cooling said molten composition containing said active substance at or below its gelling temperature to form said gel films containing said active substance.    
     
     
         45 . The process of  claim 44 , wherein said active substance is at least one of an oral care agent, a breath freshening agent, a pharmaceutical agent, a nutraceutical agent, a salivary stimulant agent, a vitamin, a mineral, a coloring agent, a sweetener, a flavorant, a fragrance, a food.  
     
     
         46 . A delivery system made by the process of  claim 44 .  
     
     
         47 . A process for making homogeneous, thermoreversible gel films comprising the steps of: 
 (i) heating, hydrating, mixing, solubilizing, and, optionally, deareating a film forming composition in an apparatus providing sufficient shear, temperature and residence time to form a highly viscous homogeneous molten composition, wherein said temperature is at or above the solubilizing temperature of said composition; and    (ii) cooling said homogeneous molten composition at or below its gelling temperature to form said gel films.    
     
     
         48 . The process of  claim 47 , wherein said apparatus is a Ross mixer.  
     
     
         49 . A process for making soft capsules comprising the steps of: 
 (i) heating, hydrating, mixing, solubilizing and, optionally, deaerating a high solids, low moisture film forming composition in an apparatus providing sufficient shear, temperature and residence time to form a highly viscous homogeneous molten composition, wherein said temperature is at or above the solubilizing temperature of said composition;    (ii) cooling said molten composition to or below the gelling temperature of the molten composition to form a homogeneous, thermoreversible gel film; and    (iii) making soft capsules from said gel film.    
     
     
         50 . The process of  claim 49 , wherein said apparatus is a Ross mixer.  
     
     
         51 . The process of  claim 2 , wherein said film forming composition does not contain a plasticizer.  
     
     
         52 . The process of  claim 2 , wherein said film forming composition contains said bulking agent, and said at least one hydrocolloid film former is carrageenan and said bulking agent is corn syrup.  
     
     
         53 . A homogeneous, thermoreversible gel film made from the process of  claim 51 , wherein said gel film has a solids content of a least 80% by weight of all components in said gel film.  
     
     
         54 . A homogeneous, thermoreversible gel film made from the process of  claim 52 , wherein said gel film has a solids content of a least 80% by weight of all components in said gel film.