Composition containing a dibenzoylmethane screening agent and a hydrophilic or water-soluble merocyanin uv-screening agent; process for photostabilizing the dibenzoylmethane screening agent

Abstract

The present invention relates to a cosmetic composition containing a combination i) of at least one screening agent of the dibenzoylmethane derivative type and ii) of at least one particular hydrophilic or water-soluble merocyanin UV-screening agent, especially corresponding to one of the formulae (I) or (II) below: in which at least one or two of the radicals contain: either an alkylsulfonate radical in its acid or salified form or one or two hydroxyl radicals. The invention also relates to a process for the radiation-photostabilization of at least one screening agent of the dibenzoylmethane derivative type with an effective amount of at least one particular hydrophilic or water-soluble merocyanin UV-screening agent, especially corresponding to one of the formulae (I) or (II).

1 . A process for improving the chemical stability towards UV radiation of at least one dibenzoylmethane derivative, which comprises combining the said dibenzoylmethane derivative is combined with an effective amount of at least one hydrophilic or water-soluble merocyanin UV-screening agent selected from the group formed by: 
       (1) those corresponding to one of the formulae (I) and (II) and also the salts thereof and the E,E-, E,Z- or Z,Z-geometrical isomer forms thereof below: 
       
         
           
           
               
               
           
         
       
       in which:
 R 1  and R 2 , which may be identical or different, represent H; a linear or branched C 1 -C 22  alkyl radical optionally containing from 1 to 3 oxygen atoms; a C 3 -C 8  cycloalkyl radical, which is unsubstituted or substituted with C 1 -C 4  alkyl radicals; the said radicals R 1  and R 2  optionally containing an alkylsulfonate radical in its acid or salified form or one or two hydroxyl radicals; 
 R 1  and R 2  may form, together with the nitrogen, a ring containing the group —(CH 2 ) m —, which is uninterrupted or interrupted with one or more —O—, —S— or —NH—, 
 R 1  may form, with the carbon alpha to the nitrogen, a ring containing the group —(CH 2 ) m —, which is uninterrupted or interrupted with one or more —O—, —S— or —NH—, 
 R 3  represents a carboxyl, —COOR 5 , —CONHR 5 , —COR 5 , —CONR 5 R 1 , SO 2 R 5  or —CN group, 
 R 4  represents a carboxyl, —COOR 6 , —CONHR 6 , —COR 6 , —CONR 6 R 2  or SO 2 R 6  group, 
 R 5  and R 6 , which may be identical or different, represent a linear or branched C 1 -C 22  alkyl radical optionally containing from 1 to 3 oxygen atoms; a C 3 -C 8  cycloalkyl radical, which is unsubstituted or substituted with C 1 -C 4  alkyl radicals; the said radicals R 5  and R 6  optionally containing an alkylsulfonate radical in its acid or salified form or one or two hydroxyl radicals, 
 Z represents the group —(CH 2 ) l —, which is uninterrupted or interrupted with —O—, —S— or —NR 7 —, and/or unsubstituted or substituted with one or two C 1 -C 6  alkyl radicals, 
 R 7  is a C 1 -C 5  alkyl radical optionally containing an alkylsulfonate radical in its acid or salified form or one or two hydroxyl radicals, 
 n is 1-2; —m is 1-7; —l is 1-4; 
 
       with at least one or two of the radicals R 1 , R 2 , R 5 , R 6  and R 7  containing
 either an alkylsulfonate radical in its acid or salified form 
 or one or two hydroxyl radicals; 
 
       with the proviso that: 
       (i) when n=2, one of the radicals R 1 , R 5  or R 6  is an alkyl diradical or R 1  and R 2  together with two nitrogen atoms form a cyclic divalent radical —(CH 2 ) m —; 
       (ii) R 1  and R 2  are not simultaneously a hydrogen atom; 
       (iii) when R 3  is —CN, then at least one of the radicals R 1 , R 2  or R 6  must contain an alkylsulfonate group in its acid or salified form; 
       (2) the merocyanin compounds selected from the group formed by the following molecules, and also salts thereof and the E,E-, E,Z- or Z,Z-geometrical isomer forms thereof: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         2 . The process according to  claim 1 , in which the compounds of formula (I) are chosen from those for which the following conditions are satisfied:
 R 1  denotes hydrogen; a linear or branched C 1 -C 8  alkyl radical optionally containing from 1 to 3 oxygen atoms,   R 2  denotes a linear or branched C 1 -C 8  alkyl radical optionally containing from 1 to 3 oxygen atoms or a C 5 -C 6  cycloalkyl radical,   R 3  denotes a group —COOR 5 , —CN or —CONHR 5 ,   R 4  denotes a group —COOR 6 , —CONHR 6  or —SO 2 R 6 ,   R 5  denotes a linear or branched C 1 -C 12  alkyl radical optionally containing from 1 to 3 oxygen atoms,   n is equal to 1 or 2;   with at least one or two of the radicals R 1 , R 2 , R 5 , R 6  containing
 either an alkylsulfonate radical in its acid or salified form 
 or one or two hydroxyl radicals. 
   
     
     
         3 . The process according to  claim 2 , in which the compounds of formula (I) containing at least one alkylsulfonate group are chosen from those having the following formulae, and also the E,E, Z,Z, E,Z isomer forms thereof: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         4 . The process according to  claim 2 , in which the compounds of formula (I) containing hydroxyl groups are chosen from those having the following formulae: 
       
         
           
           
               
               
           
         
       
     
     
         5 . The process according to  claim 1 , in which the compounds of formula (II) are chosen from those for which the following conditions are satisfied:
 R 1  denotes hydrogen; a linear or branched C 1 -C 10  alkyl radical optionally containing from 1 to 3 oxygen atoms,   R 2  denotes a linear or branched C 1 -C 10  alkyl radical optionally containing from 1 to 3 oxygen atoms; a C 5 -C 6  cycloalkyl,   R 3  denotes a group —COOR 5  or CN,   R 4  denotes a group —COOR 6  or —SO 2 R 6 ,   R 5  denotes a linear or branched C 1 -C 12  alkyl radical optionally containing from 1 to 3 oxygen atoms,   Z is —(CH 2 ) 3 — which may or may not be substituted with two groups CH 3 ,   n is equal to 1 or 2;   with at least one or two of the radicals R 1 , R 2 , R 5 , R 6  and R 7  containing
 either an alkylsulfonate radical in its acid or salified form 
 or one or two hydroxyl radicals. 
   
     
     
         6 . The process according to  claim 5 , in which the compounds of formula (II) are chosen from those having the following formulae, and also the E,E, Z,Z, E,Z isomer forms thereof: 
       
         
           
           
               
               
           
         
       
     
     
         7 . The process according to  claim 1 , in which the hydrophilic or water-soluble merocyanin UV screening agent(s) are chosen from the following compounds, and also the salts or the E,E, Z,Z, E,Z isomer forms thereof: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         8 . The process according to  claim 1 , in which the dibenzoylmethane derivative is 4-(tert-butyl)-4′-methoxydibenzoylmethane, or Butyl Methoxy Dibenzoylmethane or Avobenzone, having the following formula: 
       
         
           
           
               
               
           
         
       
     
     
         9 . A merocyanin compound with one or two alkylsulfonate radicals selected from the group consisting of the following compounds, and also salts thereof or E,E-, E,Z- or Z,Z-isomer forms thereof: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         10 . A merocyanin compounds selected from the group consisting of the following compounds, and also the salts thereof or E,E-, E,Z- or Z,Z-isomer forms thereof: