Core shell silica particles and uses thereof as an anti-bacterial agent

• US 10,369,091 B2
• Filed: 12/18/2014
• Issued: 08/06/2019
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: Colgate-Palmolive Company
• Original Assignee: Colgate-Palmolive Company
• Inventors: Pan, Guisheng, Chopra, Suman
• Primary Examiner(s): Shomer, Isaac
• Application Number:
  US15/106,445
• Publication Number:
  US 20160338920A1
• Time in Patent Office: 1,692 Days
• Field of Search: None
• CPC Class Codes: A61K 2800/28 Rubbing or scrubbing compositions; Peeling or abrasive compositions; Containing exfoliants
• CPC Class Codes: A61K 2800/621 by inorganic compounds
• CPC Class Codes: A61K 2800/651 The particulate/core comprising inorganic material
• CPC Class Codes: A61K 2800/92 Oral administration
• CPC Class Codes: A61K 8/022 Powders; Compacted Powders
• CPC Class Codes: 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
• CPC Class Codes: A61K 8/0245 Specific shapes or structures not provided for by any of the groups of A61K8/0241
• CPC Class Codes: A61K 8/0258 Layered structure
• CPC Class Codes: A61K 8/19 containing inorganic ingredients
• CPC Class Codes: A61K 8/25 Silicon; Compounds thereof
• CPC Class Codes: A61K 8/466 containing sulfonic acid derivatives; Salts
• CPC Class Codes: A61Q 11/00 Preparations for care of the teeth, of the oral cavity or of dentures; Dentifrices, e.g. toothpastes; Mouth rinses
• CPC Class Codes: C01B 33/18 Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/84 one phase coated with the other
• CPC Class Codes: C03C 15/00 Surface treatment of glass, not in the form of fibres or filaments, by etching etching or surface-brightening compositions, in general C09K13/00
• CPC Class Codes: C03C 17/22 with other inorganic material C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 17/23 Oxides C03C17/02 takes precedence
• CPC Class Codes: C09C 1/3054 Coating
• CPC Class Codes: C09K 3/1436 Composite particles, e.g. coated particles
• CPC Class Codes: C09K 3/1445 : the coating consisting exclusively of metals

Abstract

This invention provides core shell silica particles, wherein each core shell silica particle comprises a silica core, and a surface of the silica core etched with group I metal silicate. These core shell silica particles have high surface charge density and anti-bacterial activity. Also provided are compositions comprising core shell silica particles, process of making the core shell silica particles and methods of reducing or inhibiting bacterial activity by administering the core shell silica particles or compositions thereof.

Claims

1. A process for making an oral care composition comprising:

providing silica particles in water;

providing a base, wherein the base comprises a Group I metal ion;

admixing the silica particles in water with the base until the conductivity has decreased by at least 2 mS/cm as compared to the original conductivity;

combining the particles thus formed with an orally acceptable carrier to form an oral care composition.

2. The process according to claim 1, wherein the base is in solid or aqueous form, and the base is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, trisodium phosphate, disodium phosphate, potassium phosphate, dipotassium phosphate, tetrasodium pyrophosphate, and tetrapotassium pyrophosphate.

3. The process of claim 1, wherein the silica particles are selected from the group consisting of a precipitated silica, a fumed silica and a fused silica.

4. The process according to claim 2, wherein the base is 50% aqueous sodium hydroxide solution and the admixing step is carried out at a temperature of from 70 to 90°

C.

5. The process according to claim 2, wherein the base is potassium hydroxide and the admixing step is carried out at room temperature.

6. The process according to claim 1, wherein the formation of the particles thus formed is complete after a time period of 2 hrs.

7. The process according to claim 1, wherein the weight ratio for the amount of the base to the amount of silica particles is from 1:

1 to 1;

20.

8. The process according to claim 7, wherein the weight ratio for the amount of the base to the amount of silica particles is from 1:

1 to 1;

6.

9. The process according to claim 1, wherein the base is 50% aqueous sodium hydroxide solution.

10. The process according to claim 1, wherein the admixing occurs in the presence of a humectant, wherein the weight ratio for the amount of the humectant to water ranges from 4:

1 to 1;

4.

11. The process according to claim 1, wherein the admixing occurs until the conductivity has decreased by at least 5 mS/cm as compared with the original conductivity.

12. The process of claim 1, further comprising applying the oral care composition to the oral surfaces of a patient in need thereof.

13. The process of claim 1, further comprising applying the oral care composition to the surface of a removable oral device.

14. The process of claim 13, wherein the removable oral device is selected from the group consisting of a denture, tray, mouthpiece, orthodontial braces and a retainer.