Erodible film for treating the surfaces of teeth

Abstract

A thin, flexible, bilayer or multi-layer film which when applied to teeth surfaces adheres and delivers an active compound to the underlying surface and erodes at a predetermined rate. The amount of time that the active agent remains in contact with the teeth surfaces is controlled by the composition of backing layer of the composite film. This erosion or residence time can be regulated one half hour to three hours, depending upon the desired therapeutic or cosmetic application.

1 . An erodible strip comprising at least two layers, wherein one layer comprises a water soluble polymer or combination of polymers that adheres to moist enamel surfaces; and a second layer which is water erodible and controls the residence time that the strip remains adhered to the enamel surface.  
     
     
         2 . The erodible strip of  claim 1  being geometrically shaped as a strip to conform to an individual tooth or a row of teeth.  
     
     
         3 . The strip of  claim 2  wherein said water soluble polymer is at least one of polyvinyl pyrrolidone, polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, sodium carboxymethyl cellulose, polyethylene oxide, polyethylene glycol, and polyacrylic acid.  
     
     
         4 . The strip of  claim 2  wherein said first layer comprises a water soluble polymer or combination of polymers thereof and at least one tooth-whitening agent.  
     
     
         5 . The strip of  claim 4  wherein said tooth whitening agent is at least one selected from the group consisting of peroxides, metal chlorites, perborates, percarbonates, peroxyacids, and persulfates.  
     
     
         6 . The strip of  claim 4  wherein said tooth whitening agent is carbamide peroxide.  
     
     
         7 . The strip of  claim 2  wherein said second layer comprises a mixture of hydrophobic and water soluble polymers, consisting of either ethyl cellulose, methyl cellulose, or anionic, cationic and neutral polymers and copolymers of methacrylates under the trade name Eudragit®, alone or in combination thereof with at least one water soluble polymer selected from the group consisting of polyvinyl pyrrolidone, hydroxypropylmethyl cellulose, hydroxyethyl cellulose, and polyvinyl alcohol.  
     
     
         8 . The strip of  claim 7  wherein said second layer comprises a mixture of hydrophobic and water soluble polymers at a ratio of 0.5:1 to 10:1 by weight.  
     
     
         9 . The strip of  claim 8  where the ratio is 1.5:1 to 3:1 by weight.  
     
     
         10 . A strip film of  claim 1  comprising a first layer consisting of a water soluble polymer or combination of polymers that adheres to moist enamel surfaces, a laminated middle layer comprising a precast film of a water soluble polymer, and a water erodible backing layer that controls the residence time that the film remains adhered to a tooth surface.  
     
     
         11 . The strip of  claim 10  defined as is geometrically shaped to conform to an individual tooth or a row of teeth.  
     
     
         12 . The strip of  claim 10  wherein the precast water soluble polymer is hydroxypropylmethyl cellulose.  
     
     
         13 . The strip of  claim 10  wherein said first layer comprises at least one water soluble polymer and at least one tooth whitening agent.  
     
     
         14 . The strip of  claim 10  wherein a laminating solution used to effectively bind the middle layer to the other two layers is composed of at least one water soluble polymer dissolved in alcohol, water, or an aqueous alcohol mixture.  
     
     
         15 . The strip of claims  4  or  13  wherein said whitening agent is from 0.1% to 30% by weight of the strip.  
     
     
         16 . The strip of claims  4  or  13  where said whitening agent is from 0.5% to 20% by weight.  
     
     
         17 . The erodible teeth whitening strip of claims  2  or  11  defined further as containing propylene glycol, polyethylene glycol, glycerin, sorbitol, or glycerol acetate plasticizer at a concentration of 0.2% to 30% by weight.  
     
     
         18 . The strip of  claim 17  where the concentration is 0.5 to 10% by weight.  
     
     
         19 . The erodible teeth whitening strip of claims  2  or  11  defined further as containing a titanium dioxide, zinc oxide or zirconium silicate colorant or opacifier as an appearance enhancer.  
     
     
         20 . The strip of  claim 19  where the appearance enhancer is at a concentration of 0.01% to 10% by weight.  
     
     
         21 . The strip of  claim 19  where the appearance enhancer is 0.03% to 1% by weight.  
     
     
         22 . The erodible, teeth whitening strip of claims  2  and  11  defined further as containing at least one of a preservative, antioxidant, or flavor.  
     
     
         23 . The strip of  claim 19  where the appearance enhancer is at a concentration of 0.01% to 2% by weight.  
     
     
         24 . The strip of  claim 3  wherein said polymer is in a molecular weight range of between 25,000 and 1,500,000 Daltons.  
     
     
         25 . The strip of  claim 3  where said polymer is in a molecular weight range of 30,000 and 500,000 Daltons.  
     
     
         26 . The strip of claims  2  or  11  wherein said first layer comprises at least one water soluble polymer and at least one compound that dissociates to release fluoride ions for the prevention of caries.  
     
     
         27 . The strip of claims  2  or  11  wherein said first layer comprises at least one water soluble polymer and at least one phosphate compound for tartar control.  
     
     
         28 . The strip of claims  2  or  11  wherein said first layer comprises at least one water soluble polymer and at least one ingredient that can cosmetically alters the appearance of teeth.  
     
     
         29 . A mucoadhesive, erodible multi-layered device comprising a first, water-soluble adhesive layer to be placed in contact with a mucosal surface and a second, water-erodible non-adhesive backing layer that controls residence time of the device; 
 wherein said first layer comprises a tooth-whitening agent, at least one water-soluble film-forming polymer in combination with at least one mucoadhesive polymer; and said second, water-erodible non-adhesive backing layer comprises a precast film containing at least one of hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyethylene glycol, polyethylene oxide, and ethylene oxide-propylene oxide co-polymer, said backing layer being coated with at least one hydrophobic polymer, alone or in combination with at least one hydrophilic polymer, such that the backing layer is bioerodible.    
     
     
         30 . The mucoadhesive, erodible multi-layered device of  claim 29 , wherein said second water-erodible non-adhesive backing layer acts as a casting and support surface on which the adhesive layer is prepared, and comprises a premade film of hydroxypropyl methyl cellulose in combination with a coating consisting of at least one hydrophobic polymer selected from the family of quaternary ammonium acrylate/methacrylate co-polymers, (Eudragit RS) ethyl cellulose and methyl cellulose, alone or in combination with at least one hydrophilic polymer, selected from the group consisting of polyvinyl pyrrolidone, hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and polyvinyl alcohol.  
     
     
         31 . The device of  claim 29  where the tooth-whitening agent is carbamide peroxide.