Skin whiteners containing hydroxytetronic acid derivatives
View Patent ↗Skin whitening compositions contain at least one α-hydroxytetronic derivative such as diphenyl hydroxytetronic acid. Some embodiments contain adjunct ingredients that enhance the efficacy and stability of skin whitening formulations such as a tetronic acid derivative that inhibits tyrosinase or tyrosine phosphatase, hydroquinone, an α-hydroxy acid such as glycolic acid, and a fatty acid ester of ascorbic acid such as ascorbyl palmitate.
1. A method for whitening skin comprising topically administering to the skin an effective amount of a composition containing from about 0.5% to about 25% by weight of a hydroxytetronic acid derivative active ingredient having the formula
where R 1 has the formula —(CH 2 ) n -φ, where φ is a substituted or unsubstituted phenyl group and n=0 to 6 and R 2 is hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group or has the formula —(CH 2 ) n -φ, where φ is a substituted or unsubstituted phenyl group and n=0 to 6 to reduce melanin in the skin.
2. A method according to claim 1 wherein the composition contains from about 2% to about 15% by weight active ingredient.
3. A method according to claim 1 wherein the composition contains from about 3% to about 10% active ingredient.
4. A method according to claim 1 wherein the active ingredient is selected from the group consisting of 4-diphenyl-2-hydroxytetronic acid, 4-(4′-chloro)phenyl-2-hydroxy-tetronic acid, 4-(1,1′-biphenyl)-2-hydroxytetronic acid, 4-(4′-chloro-1,1′-biphenyl)-2-hydroxytetronic acid, and mixtures thereof.
5. A method according to claim 4 wherein the active ingredient is 4-diphenyl-2-hydroxytetronic acid.
6. A method according to claim 4 wherein the active ingredient is 4-(4′-chloro)-phenyl-2-hydroxytetronic acid.
7. A method according to claim 1 wherein the composition further comprises at least one adjunct ingredient selected from the group consisting of tetronic acid, a tetronic acid derivative, hydroquinone, an α-hydroxy acid, a fatty acid ester of ascorbic acid, and mixtures thereof.
8. A method according to claim 7 wherein the adjunct ingredient is a tetronic acid derivative that inhibits tyrosinase or tyrosine phosphatase.
9. A method according to claim 7 wherein one adjunct ingredient is hydroquinone.
10. A method according to claim 7 wherein one adjunct ingredient is glycolic acid.
11. A method according to claim 7 wherein one adjunct ingredient is ascorbyl palmitate.
12. A method for whitening skin comprising applying to the skin a composition containing an effective amount of an active ingredient is selected from the group consisting of 4-diphenyl-2-hydroxytetronic acid, 4-(4′-chloro)phenyl-2-hydroxytetronic acid, 4-(1,1′-biphenyl)-2-hydroxytetronic acid, 4-(4-chloro-1,1′-biphenyl)-2-hydroxy-tetronic acid, and mixtures thereof, and at least one adjunct ingredient selected from the group consisting of tetronic acid or a tetronic acid ingredient, hydroquinone, an α-hydroxy acid, and a fatty acid ester of ascorbic acid to reduce melanin in the skin.
13. A method according to claim 12 wherein the adjunct ingredient is a tetronic acid derivative that inhibits tyrosinase or tyrosine phosphatase.
14. A method according to claim 12 wherein one adjunct ingredient is hydroquinone.
15. A method according to claim 12 wherein an adjunct ingredient is glycolic acid, ascorbyl palmitate, or mixtures thereof.
16. A method according to claim 12 wherein the composition contains from about 0.5% to about 25% by weight active ingredient and from about 0.25% to about 25% by weight adjunct ingredient.
17. A method according to claim 12 wherein the active ingredient is 4-diphenyl-2-hydroxytetronic acid, 4-(4′-chloro)phenyl-2-hydroxytetronic acid, or mixtures thereof, and the adjunct ingredient is a tetronic acid derivative that inhibits tyrosinase of tyrosine phosphatase, hydroquinone, or mixtures thereof.
18. A method according to claim 17 wherein the composition contains from about 0.5% to about 15% by weight active ingredient and from about 0.5% to about 15% by weight adjunct ingredient.
19. A method for whitening skin comprising topically administering to the skin an effective amount of a composition containing 4-diphenyl-2-hydroxytetronic acid to reduce melanin in the skin.
20. A method according to claim 19 wherein the composition further contains a tetronic acid derivative that inhibits tyrosinase or tyrosine phosphatase.