Cosmetic and dermatological compositions in particular for the treatment of keratin containing substrates
The present invention relates to cosmetic and/or dermatological compositions for the treatment of keratin containing substrates, comprising synergistic mixtures of modified starch polymers with defined molecular weights and cationic charges in a cosmetically acceptable medium. The synergistic mixtures of modified starches employed to manufacture compositions according to the present invention exhibit significant benefits over the existing modified starches employed according to the state-of-the-art in the treatment of keratin-containing substrates like human or animal hair, skin and nails. Another aspect of the present invention is the stabilization of the modified starch solutions used to manufacture the cosmetic and/or dermatological compositions according to the present invention against the growth of micro-organisms without traditional preservatives.
1. A cosmetic and/or dermatological composition comprising as an effective amount of a conditioning system:
a) between 0.01-10.0 wt. % of a linear or branched modified starch polymer of the general formula
where R 1 -R 11 are independently H or a hydroxyalkyl residue of the general formula —CH 2 —CHOH—R 12 with R 12 being —CH 3 or —CH 2 NR 13 (CH 3 ) 2 + X − with R 13 ═—CH 3 or a linear or branched C 4 -C 22 -alkyl residue and with X − ═Cl − , Br − or I − , where n is such that the average molecular weight of the polymer (I) is in the range of 200,000-1,000,000 Da and where the amount of hydroxyl groups carrying a cationic charge is between 25 wt. % and 50 wt. %, which corresponds to a degree of quaternization of D.S.=0.75 and 1.50 and
b) between 0.01 and 10.0 wt. % of a linear or branched modified starch polymer of the general formula
where R 1 -R 11 are independently H or a hydroxyalkyl residue of the general formula —CH 2 —CHOH—R 12 with R 12 formula being —CH 3 or —CH 2 NR 13 (CH 3 ) 2 + X − with R 13 ═—CH 3 or a linear or branched C 4 -C 22 -alkyl residue and with X − ═Cl − , Br − or I − , where m is such that the average molecular weight of the polymer (II) is in the range of 2,000,000-8,000,000 Da and where the amount of hydroxyl groups carrying a cationic charge is between 2 wt. % and 20 wt. %, which corresponds to a degree of quaternization of D.S.=0.06 and 0.60
in a cosmetic acceptable medium.
2. The cosmetic and/or dermatological composition according to claim 1 containing an antimicrobially effective amount of a masking agent from the group of p-anisic acid and/or levulinic acid.
3. The cosmetic and/or dermatological composition according to claim 1 containing an antimicrobially effective amount of a re-fattying agent and/or humectant from the group of polyols of the general structure CH 3 (CH 2 ) x CHOHCH 2 OH with x=2-7, and/or a glycerylmonoester of fatty acids with 8-12 carbons.
4. The cosmetic and/or dermatological composition according to claim 1 containing an antimicrobially effective amount of a co-surfactant from the group of lactylates of fatty acids with 8-12 carbons.
5. The cosmetic and/or dermatological composition according to claim 1 in which the total amount of modified starch polymer is between 0.05 and 2.0 wt. % as conditioners.
6. The cosmetic and/or dermatological composition according to claim 5 in which the ratio of the modified starch polymers a) and b) is between 5:1 and 1:5.
7. The cosmetic and/or dermatological composition according to claim 6 containing as antimicrobially effective masking agent p-anisic acid and/or levulinic acid in concentrations between 0.0005 and 0.5 wt. % each.
8. The cosmetic and/or dermatological composition according to claim 6 containing as antimicrobially effective re-fattying agent and/or humectant one or more polyols of the general structure CH 3 (CH 2 ) x CHOHCH 2 OH with x=2-7 or a glycerylmonoester of fatty acids with 8-12 carbons in concentrations between 0.002 and 2 wt. %.
9. The cosmetic and/or dermatological composition according to claim 6 , containing as antimicrobially effective co-surfactant one or more lactylates of fatty acids with 8-12 carbons in concentrations between 0.002 and 2 wt. %.
10. A method for treating keratin containing substrates which comprises applying to said substrate a cosmetic and/or dermatological composition according to claim 1 .
11. The method of claim 10 wherein the keratin containing substrate comprises hair or skin.