Treatment of excessive radiation (e.g. sunburn) exposure

Abstract

A method is disclosed whereby a formulation is applied to the skin of a patient which may be a human. The formulation is comprised of a carrier and a compound which has a first lipid solubility and a first aqueous solubility. The compound is allowed to permeate the patient's skin and reach viable cells and react in the presence of enzymes of the cells. The reaction results in a compound which has a second lipid solubility which is substantially less than the first lipid solubility and also obtain a second aqueous solubility which is substantially greater than the first aqueous solubility thereby allowing the compound to permeate to viable cells and remain in contact with those cells. The compound may be a nitroxide which aids in modulating adverse effects of reactive oxygen species.

What is claimed is:  
     
         1 . A method of treatment, comprising: 
 applying to the skin of a patient a topical formulation comprising a carrier and a compound with a first lipid solubility and a first aqueous solubility;    allowing the compound to permeate to viable cells of the skin and react in the presence of enzymes in the viable cells to obtain a second lipid solubility which is less than the first lipid solubility and further obtain a second aqueous solubility which is greater than the first aqueous solubility.    
     
     
         2 . The method of  claim 1 , wherein the lipid solubility is a solubility in a lipid generally present in human skin and the aqueous solubility is a solubility in an aqueous environment of a cell.  
     
     
         3 . The method of  claim 2 , wherein the first lipid solubility is twice or more than the second lipid solubility and the first aqueous solubility is one half or less the second aqueous solubility.  
     
     
         4 . The method of  claim 3 , wherein the formulation is applied prior to the skin being exposed to excessive radiation.  
     
     
         5 . The method of  claim 3 , wherein the formulation is applied prior to exposure to sunlight.  
     
     
         6 . The method of  claim 3 , wherein the formulation is applied after the skin is exposed to excessive radiation.  
     
     
         7 . The method of  claim 6 , wherein the formulation is applied within a period of about thirty minutes to about two hours after exposure to excessive radiation.  
     
     
         8 . The method of  claim 7 , wherein the radiation is sunlight and the compound modulates an effect of reactive oxygen species.  
     
     
         9 . A method of  claim 8 , wherein the compound is a nitroxide.  
     
     
         10 . The method of  claim 9 , wherein the nitroxide is comprised of a first portion comprising a nitrogen atom and an oxygen atom bound directly together and an unpaired electron (•NO), a second portion which provides a negative charge, and a linking group positioned between and bound to the first portion and the second portion in a manner such that the negative charge of the first portion stabilizes the •NO of the first portion when the nitroxide is present in the patient.  
     
     
         11 . The method of  claim 9 , wherein the nitroxide has the general structural formula I:  
       
         
           
           
               
               
           
         
         wherein R 1  is a nitroxide;  
         wherein R 2  and R 3  are each independently chosen from Na, K, hydrogen, alkyl, alkenyl, acyl, aralkyl, alkaryl and a nitroxide; and  
         wherein “n” is an integer of from 0 to 18.  
       
     
     
         12 . The method of  claim 9 , wherein the nitroxide has the general structural formula II:  
       
         
           
           
               
               
           
         
         wherein R 1  is a nitroxide;  
         wherein R 2  and R 3  are each independently chosen from Na, K, hydrogen, alkyl, alkenyl, acyl, aralkyl, alkaryl and a nitroxide; and  
         wherein “n” is an integer of from 1 to 6.  
       
     
     
         13 . The method of  claim 9 , wherein the nitroxide has the general structural formula III:  
       
         
           
           
               
               
           
         
         wherein R 1  is a nitroxide;  
         wherein R 2  and R 3  are each independently chosen from Na, K, hydrogen, alkyl, alkenyl, acyl, aralkyl, alkaryl and a nitroxide; and  
         wherein “n” is an integer of from 1-6.  
       
     
     
         14 . The method of  claim 9 , wherein the nitroxide has the general structural formula IV:  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are each independently an alkyl and the circle is a cyclic moiety comprising carbon atoms.  
       
     
     
         15 . The method of  claim 1 , further comprising: 
 applying a UV absorber to the skin.    
     
     
         16 . A formulation, comprising: 
 a dermatologically acceptable carrier;    a UV absorber; and    a nitroxide.    
     
     
         17 . The formulation of  claim 16 , wherein the nitroxide has the general structural formula I:  
       
         
           
           
               
               
           
         
         wherein R 1  is a nitroxide;  
         wherein R 2  and R 3  are each independently chosen from Na, K, hydrogen, alkyl, alkenyl, acyl, aralkyl, alkaryl and a nitroxide; and  
         wherein “n” is an integer of from 0 to 18.  
       
     
     
         18 . The formulation of  claim 16 , wherein the nitroxide has the general structural formula II:  
       
         
           
           
               
               
           
         
         wherein R 1  is a nitroxide;  
         wherein R 2  and R 3  are each independently chosen from Na, K, hydrogen, alkyl, alkenyl, acyl, aralkyl, alkaryl and a nitroxide; and  
         wherein “n” is an integer of from 1 to 6.  
       
     
     
         19 . The formulation of  claim 16 , wherein the nitroxide has the general structural formula III:  
       
         
           
           
               
               
           
         
         wherein R 1  is a nitroxide;  
         wherein R 2  and R 3  are each independently chosen from Na, K, hydrogen, alkyl, alkenyl, acyl, aralkyl, alkaryl and a nitroxide; and  
         wherein “n” is an integer of from 1-6.  
       
     
     
         20 . The formulation of  claim 16 , wherein the nitroxide has the general structural formula IV:  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are each independently an alkyl and the circle is a cyclic moiety comprising carbon atoms.