# US 7,588,747 B2 · Singlet oxygen quencher and composition using the same

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- Number: US 7,588,747 B2
- Document ID: US7588747B2
- Status: Granted
- Kind: B2
- Application number: 10/568,875
- Filed: 2004-08-20
- Published: 2007-04-26
- Granted: 2009-09-15
- Earliest claimed: 2003-08-22
- Assignees: Kose Corporation; APT, Inc.
- Inventors: Noboru Naito; Kumi Kameyama; Akemi Takayama; Misako Kobayashi; Yusei Miyamoto; Masashi Kajita
- Web page: https://patentgrep.com/patent/US7588747B2

## CPC

- A61K 8/19: containing inorganic ingredients
- A61P 17/18: Antioxidants, e.g. antiradicals (preparations for protection against sunlight A61Q17/00)
- A61Q 17/04: Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
- A61Q 19/08: Anti-ageing preparations
- A61K 2800/522: Antioxidants; Radical scavengers
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS

## Abstract

A novel singlet oxygen quencher is disclosed. The quencher consists of a colloidal liquid of a platinum metal group. A composition comprising, as an active ingredient, the singlet oxygen quencher is also disclosed.

## Claims

### Claim 1

A singlet oxygen quencher consisting of a colloidal liquid of at least one platinum metal group member and a water soluble polymer, wherein
the at least one platinum metal group member is chosen from platinum and rhodium;
the platinum metal group member has a particle size equal to or smaller than 50 nm; and
the water soluble polymer is chosen from polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylic acid, cyclodextrin, aminopectin, methyl cellulose, and combinations thereof.

### Claim 2 (depends on 1)

The singlet oxygen quencher as set forth in claim 1 having a rate constant for quenching singlet oxygen of 1.0×108M−1s−1 or above.

### Claim 3 (depends on 1)

The singlet oxygen quencher as set forth in claim 1, wherein the colloidal liquid is a colloidal liquid of a single platinum metal group member.

### Claim 4 (depends on 1)

The singlet oxygen quencher as set forth in claim 1, used as a collagen cross-linkage inhibitor, instantaneous melanism inhibitor, enzyme inactivation inhibitor, lipid hyperoxidation inhibitor, cell ageing inhibitor or color fading inhibitor.

### Claim 5 (depends on 1)

A composition comprising as an active ingredient a singlet oxygen quencher as set forth in claim 1.

### Claim 6 (depends on 1)

The singlet oxygen quencher as set forth in claim 1, wherein the colloidal liquid of the at least one platinum metal group member is prepared according to a metal salt reduction process.