Composition for topical substance delivery

Abstract

A polymerized hydrogel composition for hydrating or dehydrating a surface, particularly a dermatological surface, to which it is applied and a method for forming the composition. The composition is comprised of a mixture of two polymerizable materials, a two-part redox catalyst system and a two-part polymerization medium. The percentage by weight of each element in the composition may be varied within stated percentage ranges and depending to the desired application. The rate at which hydration or dehydration occurs may be controllably altered by varying the percentages of certain of the composition elements and by adding either or both of a fibrous filler material and a humectant to the composition.

What is claimed is:  
     
         1 . A reusable, nonbioadhesive, microporous hydrogel composition for hydrating or dehydrating a surface with which the composition is placed in contact at a variable, controllable and customizable moisture release or moisture absorption rate comprised of: 
 a hydrophilic acrylate-based monomer in the range of 26% to 35% by weight of the composition;    a crosslinking agent in the range of 1% to 1.8% by weight of the composition;    a polymerization initiator;    water in the range of 62% to 72% by weight of the composition;    an aliphatic alcohol in the range between 0% and 11% by weight of the composition;    at least one humectant; and    a predetermined amount of a preselected type of fibrous filler material having known moisture absorption characteristics.    
     
     
         2 . The composition of  claim 1  wherein said fibrous filler material is insoluble in water, acrylate monomers, aliphatic alcohol, propylene glycol or humectant.  
     
     
         3 . The composition of  claim 2  wherein said fibrous filler material is further comprised of polar polymers.  
     
     
         4 . The composition of  claim 2  wherein said fibrous filler material is further comprised of non-polar polymers.  
     
     
         5 . The composition of  claim 2  wherein the predetermined amount of said fibrous filler material is that amount of said material which, based on the known moisture absorption capacity of said material, will achieve moisture saturation when mixed with a known volume of other composition elements to which it will be added.  
     
     
         6 . The composition of  claim 1  wherein the amount and type of said humectant is dependent on the rate and amount of moisture desorption desired in the composition.  
     
     
         7 . The composition of  claim 6  wherein said humectant is infused into the composition prior to polymerization and constitutes in the range of 0% to 15% of the desired total volume by weight of the final composition.  
     
     
         8 . The composition of  claim 6  wherein said humectant is infused into the composition after polymerization has occurred and constitutes in the range of 0% to 100% of the final total volume of the infusing solution.  
     
     
         9 . A method for making a specified amount of a reusable, nonbioadhesive, microporous hydrogel composition useful for hydrating or dehydrating a surface to which it is applied at a variable, controllable and customizable moisture release or moisture absorption rate and for forming the composition into a desired shape based on use of a two-part polymerization medium, two polymerizable materials, a two-part redox catalyst system for polymerization initiation, at least one humectant and fibrous filler material having known moisture absorption characteristics, comprising the steps of: 
 weighing out an amount of distilled water as the first part of the polymerization medium within the range of 62% and 72% by weight of the amount of composition desired to be made;    weighing out an amount of a low molecular weight aliphatic alcohol as the second part of the polymerization medium within the range of 0% and 11% by weight of the amount of composition desired to be made;    combining the resulting distilled water and the resulting low molecular weight aliphatic alcohol into a mixture;    weighing out an amount of a first, hydrophilic, acrylate-based polymerizable material within the range of 26% and 35% by weight of the amount of composition desired to be made;    weighing out an amount of a second polymerizable material within the range of 1% and 1.8% by weight of the amount of composition desired to be made;    adding the resulting first and second polymerizable materials to the mixture;    weighing out an amount of the first part of the redox catalyst system within the range of 0.3% and 0.5% by weight of the amount of composition desired to be made;    thoroughly dissolving the first part of the redox catalyst system in the mixture;    further adding at least one humectant in the range of 0% to 15% of the desired total volume by weight of the final composition to the mixture;    weighing out an amount of the second part of the redox catalyst system within the range of 0.1% and 0.3% by weight of the amount of composition desired to be made;    adding the resulting second part of the redox catalyst system to the mixture;    blending fibrous filler material into the mixture in an amount thereof which, based on the known moisture absorption characteristics of the filler, will achieve moisture saturation when mixed with the known volume of other composition elements to which it will be added;    transferring the resultant mixture to a mold within approximately two minutes after adding the second part of the redox catalyst system to the mixture;    removing the composition from the mold within between twenty and twenty-five minutes after adding the second part of the redox catalyst system to the mixture; and    washing the molded composition in a large volume of water for a period of at least twenty-four hours.    
     
     
         10 . The method of  claim 9  wherein the blending step is replaced by the steps of: 
 placing a predetermined amount of the fibrous filler material onto a surface;  
 pouring the mixture over the fibrous filler material;  
 
     
     
         11 . The method of  claim 9  wherein, when a molding method is used in which a predictable distribution of a precise mass of fibers throughout a precise volume of polymer is not inherent, the following step is added after the blending step: 
 applying pressure to the exterior, exposed side of the composition until polymerization is complete.  
 
     
     
         12 . The method of  claim 11  wherein pressure is applied through a solid, flat surface placed on top of the exterior, exposed surface of the composition.  
     
     
         13 . The method of  claim 9  wherein the further adding step is omitted and is replaced after the washing step with the step of: 
 infusing at least one humectant into the composition constituting in the range of 0% to 100% of the final total volume of the infusing solution.  
 
     
     
         14 . The method of  claim 9  further comprising, after the transferring step, the step of: 
 covering the exterior, exposed surface of the composition during polymerization.  
 
     
     
         15 . The method of  claim 9  further comprising, after the transferring step, the step of: 
 purging the exterior, exposed surface of the composition with a suitable gas during polymerization.  
 
     
     
         16 . A method for controllably increasing the rate and amount of moisture absorption of a reusable, nonbioadhesive, microporous hydrogel composition having a hydrophilic acrylate-based monomer with a range of between 26% and 35% by weight of the composition, a crosslinking agent with a range of between 1% and 1.8% by weight of the composition, AP with a range of between 0.3% and 0.5% by weight of the composition, TEMED with a range of between 0. 1% and 0.3% by weight of the composition, distilled water with a range of between 62% and 72% by weight of the composition, a low molecular weight aliphatic alcohol with a range of between 0% and 11% by weight of the composition, at least one humectant and fibrous filler material comprising any one or more of the following steps: 
 adding a predetermined amount of a preselected type of at least one polar fibrous filler material to the composition prior to polymerization;    altering the geometry of the composition so as to increase the exposed surface area in a given sample; and    if pressure is applied to saturate the fibrous filler material during polymerization, reducing the amount of pressure to which the composition is subjected during polymerization.    
     
     
         17 . The method of  claim 16  wherein the polar fibrous filler material has higher physisorption and chemisorption characteristics than other fibrous filler material.  
     
     
         18 . A method for controllably decreasing the rate and amount of moisture desorption of a reusable, nonbioadhesive, microporous hydrogel composition having a hydrophilic acrylate-based monomer with a range of between 26% and 35% by weight of the composition, a crosslinking agent with a range of between 1% and 1.8% by weight of the composition, AP with a range of between 0.3% and 0.5% by weight of the composition, TEMED with a range of between 0.1% and 0.3% by weight of the composition, distilled water with a range of between 62% and 72% by weight of the composition, a low molecular weight aliphatic alcohol with a range of between 0% and 11% by weight of the composition, at least one humectant and fibrous filler material, comprising any one or more of the following steps: 
 adding a predetermined amount of a preselected type of at least one polar fibrous filler material to the composition prior to polymerization;    if pressure is applied to saturate the fibrous filler material during polymerization, increasing the amount of pressure to which the composition is subjected during polymerization;    altering the geometry of the composition so as to decrease the number of exposed surfaces in a given sample; and    infusing a larger amount of humectant into the composition.