# US 2025/0152484 A1 · Oil-in-water emulsion skin preparation for external use

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- Number: US 2025/0152484 A1
- Document ID: US20250152484A1
- Status: Published application
- Kind: A1
- Application number: 18/833,567
- Filed: 2023-01-19
- Published: 2025-05-15
- Earliest claimed: 2022-01-28
- Assignees: Kao Corporation
- Applicants: Kao Corporation
- Inventors: Tomoya FUJII; Shingo HIRONO
- Web page: https://patentgrep.com/patent/US20250152484A1

## CPC

- A61K 8/0241: {Containing particulates characterized by their shape and/or structure (see also A61K8/04, A61K8/11, and A61K8/14, further aspects are classified in A61K2800/40 and subcodes)}
- A61K 8/25: Silicon; Compounds thereof
- A61K 8/062: {Oil-in-water emulsions}
- A61K 8/37: Esters of carboxylic acids
- A61K 8/416: {Quaternary ammonium compounds (A61K8/35 takes precedence)}
- A61K 8/4913: {having five membered rings, e.g. pyrrolidone carboxylic acid}
- A61K 8/731: {Cellulose; Quaternized cellulose derivatives}
- A61K 8/898: containing nitrogen, e.g. amodimethicone, trimethyl silyl amodimethicone or dimethicone propyl PG-betaine
- A61Q 17/04: Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
- A61Q 19/00: Preparations for care of the skin
- A61K 2800/412: Microsized, i.e. having sizes between 0.1 and 100 microns
- A61K 2800/5426: cationic
- 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)
- A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS

## Abstract

Provided are an external preparation for skin of oil-in-water type emulsification containing silica particles having an average particle diameter of 0.3 μm to 3 μm; at least one selected from the group consisting of a cationic polymer having a hydrophobic moiety, and a cationic surfactant having an alkyl group; an oily component; and an aqueous component, and a method for producing the external preparation for skin of oil-in-water type emulsification

## Claims

### Claim at position 1

1: An external preparation for skin of oil-in-water type emulsification, comprising components (A), (B), (C), and (D):
(A) silica particles having an average particle diameter of from 0.3 μm to 3 μm;
(B) at least one selected from the group consisting of (B1) a cationic polymer having a hydrophobic moiety, and (B2) a cationic surfactant having an alkyl group;
(C) an oily component; and
(D) an aqueous component.

### Claim at position 2 (depends on 1)

2: The external preparation for skin of oil-in-water type emulsification according to claim 1, wherein the component (A) is aligned at an interface between the water phase and the oil phase.

### Claim at position 3 (depends on 1)

3: The external preparation for skin of oil-in-water type emulsification according to claim 1, wherein the cationic polymer or the cationic surfactant as the component (B) is adsorbed to the silica particles as the component (A).

### Claim at position 4 (depends on 1)

4: The external preparation for skin of oil-in-water type emulsification according to claim 1, further comprising a component (E) as a thickener.

### Claim at position 5 (depends on 1)

5: The external preparation for skin of oil-in-water type emulsification according to claim 1, wherein the component (B1) is a cationic polymer having at least one type of hydrophobic moiety selected from the group consisting of a polysiloxane moiety, a hydrocarbon moiety, and an alkyleneoxy moiety having at least 3 carbon atom.

### Claim at position 6 (depends on 1)

6: The external preparation for skin of oil-in-water type emulsification according to claim 1, wherein the component (B1) is at least one selected from the group consisting of a cationic silicone, a cationic vinyl polymer, and a cationized cellulose derivative.

### Claim at position 7 (depends on 1)

7: The external preparation for skin of oil-in-water type emulsification according to claim 1, wherein a content of the component (A) is at least 0.5 mass %.

### Claim at position 8 (depends on 1)

8: The external preparation for skin of oil-in-water type emulsification according to claim 1, wherein the component (C) comprises at least one selected from the group consisting of an ultraviolet absorber and an ester oil.

### Claim at position 9 (depends on 1)

9: A method for producing the external preparation for skin of oil-in-water type emulsification according to claim 1, the method comprising:
mixing the component (A) with the component (B) in water.