Surface treatment composition for soft substrates

Abstract

A method for reducing the friability of soft substrates by applying an effective amount of a water soluble, polymeric dispersion to at least a portion of a treatment surface of the substrate, such that less than about 90% of the exterior surface has the dispersion applied thereto.

We claim:  
     
         1 . A treated pharmaceutical substrate comprised of: 
 a) a soft pharmaceutical substrate having a hardness value of no more than about 15 kp/cm 2  and comprised of an exterior surface having an exterior surface area, said exterior surface comprised of at least one treatable surface; and    b) a pharmaceutically-acceptable, water dispersible polymer layer in contact with at least a portion of said treatable surface to form a treated surface, 
 wherein said treated surface has a total surface area that is less than the total exterior surface area of the exterior surface, and the treated pharmaceutical substrate possesses a friability factor of at least about 2.  
   
     
     
         2 . The treated pharmaceutical substrate of  claim 1  wherein the treated pharmaceutical substrate contains from about 3 μg to about 20 μg of polymer per square millimeter of treated surface.  
     
     
         3 . The treated pharmaceutical substrate of  claim 1  wherein the treated pharmaceutical substrate contains from about 5 μg to about 9 μg of polymer per square millimeter of treated surface.  
     
     
         4 . The treated pharmaceutical substrate of  claim 1  wherein the surface area of the treated surface is, based upon the exterior surface area of the exterior surface, from about 10% to about 90%.  
     
     
         5 . The treated pharmaceutical substrate of  claim 1  wherein the surface area of the treated surface is, based upon the exterior surface area of the exterior surface, from about 20% to about 50%.  
     
     
         6 . The treated pharmaceutical substrate of  claim 1  wherein the soft pharmaceutical substrate has a hardness value from about 1 kp/cm 2  to about 8 kp/cm 2  prior to application of the dispersion and the treated pharmaceutical substrate has a hardness value of no more than about 8 kp/cm 2 .  
     
     
         7 . The treated pharmaceutical substrate of  claim 6  wherein the soft pharmaceutical substrate has a hardness value from about 1 kp/cm 2  to about 5 kp/cm 2  prior to application of the dispersion and the treated pharmaceutical substrate has a hardness value of no more than about 5 kp/cm 2 .  
     
     
         8 . The treated pharmaceutical substrate of  claim 1  having a friability factor of at least about 3.  
     
     
         9 . The treated pharmaceutical substrate of  claim 8  having a friability factor of at least about 5.  
     
     
         10 . The treated pharmaceutical substrate of  claim 1 , wherein the polymeric dispersion is comprised of film forming polymers, gelling polymers, adhesive polymers, and derivatives, copolymers, and mixtures thereof.  
     
     
         11 . The treated pharmaceutical substrate of  claim 10 , wherein in the polymeric dispersion is comprised of polyvinylalcohol (PVA), hydroxypropyl starch, hydroxyethyl starch, pullulan, methylethyl starch, carboxymethyl starch, methylcellulose, hydroxypropylcellulose (HPC), hydroxyethylmethylcellulose (HEMC), hydroxypropylmethylcellulose (HPMC), hydroxybutylmethylcellulose (HBMC), hydroxyethylethylcellulose (HEEC), hydroxyethylhydroxypropylmethyl cellulose (HEMPMC), methacrylic acid copolymers, methacrylate ester copolymers, polyvinyl alcohol and polyethylene glycol copolymers, proteins such as whey protein, egg albumin, casein, casein isolates, soy protein and soy protein isolates, pre-gelatinized starches, corn syrup solids, film-forming modified starches, and copolymers, derivatives and mixtures thereof.  
     
     
         12 . The treated pharmaceutical substrate of  claim 11 , wherein the polymeric dispersion comprises at least one polymer selected from the group consisting of hydroxypropylmethylcellulose, hydroxypropylcellulose, polyvinyl alcohol and polyethylene glycol copolymer hydroxypropyl starch, corn syrup solids, maltodextrin, pullulan, gelatin, and tapioca dextrin and copolymers, derivatives and mixtures thereof.  
     
     
         13 . The treated pharmaceutical substrate of  claim 1 , wherein the soft pharmaceutical substrate contains an active agent selected from the group consisting of acetaminophen, ibuprofen, pseudoephedrine, famotidine, or pharmaceutically acceptable salts thereof, and mixtures thereof.  
     
     
         14 . The treated pharmaceutical substrate of  claim 1 , wherein the treatable surface is a first land having a first surface and a second land having a second surface, and the polymeric layer is in contact with at least a portion of said first surface and/or said second surface.  
     
     
         15 . The treated pharmaceutical substrate of  claim 1 , wherein the treatable surface is a rim having a rim surface, and the polymeric layer is in contact with at least a portion of the rim surface.  
     
     
         16 . The treated pharmaceutical substrate of  claim 1 , wherein the treatable surface is bellyband having a bellyband surface, and the polymeric layer is in contact with at least a portion of said bellyband surface.  
     
     
         17 . The treated pharmaceutical substrate of  claim 1 , wherein the treatable surface is a face having a face surface, and the polymeric layer is in contact with at least a portion of said face surface.  
     
     
         18 . A method for reducing the friability of a soft pharmaceutical substrate having a hardness value of no more than about 15 kp/cm 2 , said soft pharmaceutical substrate comprised of an exterior surface having at least one treatable surface, comprised of: 
 applying an effective amount of a pharmaceutically-acceptable, water dispersible polymeric dispersion to at least a portion of said treatable surface to yield a treated pharmaceutical substrate,    wherein said treatable surface has a total surface area that is smaller than the total exterior surface area of the exterior surface, and the treated pharmaceutical substrate possesses a friability factor of at least about 2.    
     
     
         19 . The method of  claim 18  wherein the friability is at least about 3.  
     
     
         20 . The method of  claim 18  wherein the friability is at least about 5.  
     
     
         21 . The method of  claim 18  wherein the treated pharmaceutical substrate contains from about 3 μg to about 20 μg of polymer per squared millimeter of treated surface.  
     
     
         22 . The method of  claim 18  wherein the treated pharmaceutical substrate contains from about 5 μg to about 9 μg of polymer per squared millimeter of treated surface.  
     
     
         23 . The method of  claim 18  wherein the surface area of the treated surface is, based upon the exterior surface area of the exterior surface, from about 10% to about 90%.  
     
     
         24 . The method of  claim 18  wherein the surface area of the treated surface is, based upon the exterior surface area of the exterior surface, from about 20% to about 50%.  
     
     
         25 . The method of  claim 18  wherein the soft pharmaceutical substrate has a hardness value from about 1 kp/cm 2  to about 8 kp/cm 2  prior to application of the dispersion and the treated pharmaceutical substrate has a hardness value of no more than about 8 kp/cm 2 .  
     
     
         26 . The method of  claim 18  wherein the soft pharmaceutical substrate has a hardness value from about 1 kp/cm 2  to about 5 kp/cm 2  prior to application of the dispersion and the treated pharmaceutical substrate has a hardness value of no more than about 5 kp/cm 2 .  
     
     
         27 . The method of  claim 18 , wherein the polymer comprises at least one polymer selected from the group consisting of hydroxypropylmethylcellulose, hydroxypropylcellulose, polyvinyl alcohol and polyethylene glycol copolymer hydroxypropyl starch, corn syrup solids, maltodextrin, pullulan, gelatin, and tapioca dextrin, and derivatives, and copolymers thereof.  
     
     
         28 . A treated immediate-release pharmaceutical substrate comprised of: 
 a) a soft pharmaceutical substrate having a hardness value of no more than about 15 kp/cm 2  and comprised of an exterior surface having an exterior surface area, said exterior surface comprised of at least one treatable surface; and    b) a pharmaceutically-acceptable polymer layer in contact with at least a portion of said treatable surface to form a treated surface, 
 wherein said treated surface has a total surface area that is smaller than the total exterior surface area of the exterior surface, and the treated pharmaceutical substrate possesses immediate release properties and a friability factor of at least about 2.  
   
     
     
         29 . A treated pharmaceutical substrate comprised of: 
 a) a soft pharmaceutical substrate having a hardness value of no more than about 15 kp/cm 2  and comprised of an exterior surface having an exterior surface area, said exterior surface comprised of at least one treatable surface; and    b) a pharmaceutically-acceptable, water dispersible polymer layer in contact with at least a portion of said treatable surface to form a treated surface, 
 wherein the weight of said water dispersible polymer layer is not more than about 0.5% of the weight of the untreated substrate, and the treated pharmaceutical substrate possesses a friability factor of at least about 2.