Dihydropyridazine antioxidant sunscreens

Patent metadata

Field	Value
Publication number	US-11325925-B2
Application number	US-201816643809-A
Country	US
Kind code	B2
Filing date	Sep 4, 2018
Priority date	Sep 1, 2017
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

Herein polymers and particles which comprise a plurality of dihydropyridazine or hydropyridazine functional groups are described. Methods for their formation and specific monomers which may be used in their formation are also described. The polymers and particles are UV absorbing, hydrogen-donor antioxidant materials which signal a depletion of antioxidant ability by a decrease in visible fluorescence. These polymers and particles may be used as UV protectants for a variety of materials and substrates and may even be used in a topically applied formulation for human skin.

First claim

What is claimed is:

1. An antioxidant, UVA and UVB absorbing monomer, wherein the monomer comprises a dihydropyridazine or hydropyridazine functional group, wherein the monomer further comprises at least one alkoxysilane functional group, wherein the monomer is configured to react with one or more co-monomers to form a UV absorbing organosilicon particle,
wherein the dihydropyridazine or hydropyridazine functional groups are capable of being oxidized to one or more pyridazine functional groups by consuming one or more surrounding oxidizing species, thereby providing the monomer an ability to act as an antioxidant,
wherein the dihydropyridazine or hydropyridazine functional groups are fluorescent and the pyridazine functional groups are less fluorescent,
wherein an oxidation of said dihydropyridazine or hydropyridazine functional groups causes a depletion of said ability to act as an antioxidant, and wherein said oxidation can be detected by a decrease of a fluorescent intensity of said polymer.

2. The monomer of claim 1 , wherein the monomer comprises at least one of the following structures:

wherein,
X=0-2 R 1 =R 2 or R 1 ∜R 2 p=1-4
R 1 =H, alkyl, aryl, CO 2 alkyl, NHAlkyl, Ndialkyl, Cl, Oalkyl, Oaryl, Salkyl
R 2 =H, alkyl, aryl, CO 2 alkyl, NHAlkyl, Ndialkyl, Cl, Oalkyl, Oaryl, Salkyl
R 3 =R 4 or R 3 ≠R 4 R 3 =H, alkyl, aryl R 4 =H, alkyl, aryl
R 5 =H, alkyl, aryl, Oalkyl, Salkyl, 1°, 2° alkyl or aryl amine, CN, Cl, CO 2 alkyl.

3. The monomer of claim 1 , wherein the co-monomer comprises an alkyl orthosilicate.

4. The monomer of claim 1 , wherein the monomer is colorless before and after oxidation.

5. A method of forming a UV absorbing organosilicon particle, wherein the particle comprises a plurality of dihydropyridazine or hydropyridazine functional groups, and wherein the particle is configured to absorb UVA and UVB light, the method comprising:
a. providing a UV absorbing monomer, wherein the monomer comprises a dihydropyridazine or hydropyridazine functional group, and wherein the monomer comprises at least one alkoxysilane functional group;
b. providing an orthosilicate co-monomer; and
c. mixing said monomer and co-monomer, wherein the monomer and co-monomer react in a condensation reaction to form said organosilicon particle.

6. The method of claim 5 , wherein the UV absorbing monomer comprises a dialkyl 1,2,4,5-dihydropyridazine-3,6-dicarboxylate derivative.

7. The method of claim 5 , wherein the co-monomer comprises an alkyl orthosilicate.

8. The method of claim 5 , wherein a catalyst is used in a reaction between the monomer and co-monomer.

9. The method of claim 5 , wherein the dihydropyridazine or hydropyridazine functional groups are capable of being oxidized to one or more pyridazine functional groups by consuming one or more surrounding oxidizing species, thereby providing the particle an ability to act as an antioxidant.

10. The method of claim 9 , wherein the dihydropyridazine or hydropyridazine functional groups are fluorescent and the pyridazine functional groups are less fluorescent.

11. The method of claim 10 , wherein an oxidation of said dihydropyridazine or hydropyridazine functional groups causes a depletion of said ability to act as an antioxidant, and wherein said oxidation can be detected by a decrease of a fluorescent intensity of said polymer.

12. The method of claim 11 , wherein said oxidation causes the particle to have a decreased ability to absorb UV light.

Assignees

• Univ Arizona

Inventors

• Loy Douglas A
• Bagge Robb E
• Sun Wenmo
• Nanayakkara Nanayakkarawasan Pallage Ravindu

Classifications

• A61K2800/522

  Antioxidants; Radical scavengers · CPC title

• C08G77/54

  Nitrogen-containing linkages · CPC title

• C08F279/02

  on to polymers of conjugated dienes · CPC title

• C08F136/18

  containing chlorine · CPC title

• A61Q17/04

  Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations · CPC title