METHOD FOR PREPARING PARTICLES COMPRISING METAL OXIDE COATING AND PARTICLES WITH METAL OXIDE COATING

• US 20100016443A1
• Filed: 02/03/2008
• Published: 01/21/2010
• Est. Priority Date: 02/01/2007
• Status: Active Application

• Current Assignee: Sol-Gel Technologies Ltd.
• Original Assignee: Sol-Gel Technologies Ltd.
• Inventors: Bilman, Nissim, Sriadibhatla, Srikanth, Toledano, Ofer, Abu-Reziq, Raed, Sommer, William T., Shapiro, Leora, Bar-Simantov, Haim
• Application Number:
  US12/525,331
• Publication Number:
  US 20100016443A1
• Time in Patent Office: Days
• US Class Current: 514/699
• CPC Class Codes: A01N 2300/00 Combinations or mixtures of active ingredients covered by classes A01N27/00 - A01N65/48 with other active or formulation relevant ingredients, e.g. specific carrier materials or surfactants, covered by classes A01N25/00 - A01N65/48
• CPC Class Codes: A01N 25/26 in coated particulate form
• CPC Class Codes: A01N 53/00 Biocides, pest repellants or attractants, or plant growth regulators containing cyclopropane carboxylic acids or derivatives thereof
• CPC Class Codes: A61K 2800/412 Microsized, i.e. having sizes between 0.1 and 100 microns
• CPC Class Codes: A61K 8/11 Encapsulated compositions
• CPC Class Codes: A61K 8/25 Silicon; Compounds thereof
• CPC Class Codes: A61K 8/38 Percompounds, e.g. peracids
• CPC Class Codes: A61K 8/671 Vitamin A; Derivatives thereof, e.g. ester of vitamin A acid, ester of retinol, retinol, retinal
• CPC Class Codes: A61K 9/501 Inorganic compounds
• CPC Class Codes: A61K 9/5021 Organic macromolecular compounds
• CPC Class Codes: A61K 9/5026 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• CPC Class Codes: A61K 9/5073 having two or more different coatings optionally including drug-containing subcoatings
• CPC Class Codes: A61P 17/00 Drugs for dermatological disorders
• CPC Class Codes: A61P 17/04 Antipruritics
• CPC Class Codes: A61P 17/06 Antipsoriatics
• CPC Class Codes: A61P 17/08 Antiseborrheics
• CPC Class Codes: A61P 17/10 Anti-acne agents
• CPC Class Codes: A61Q 19/00 Preparations for care of the skin
• CPC Class Codes: B01J 13/02 Making microcapsules or microballoons for medical preparations A61K9/50
• CPC Class Codes: B01J 13/22 Coating
• CPC Class Codes: C09C 3/063 : Coating
• CPC Class Codes: Y10T 428/2991 : Coated

Abstract

The invention relates to a process for coating a solid, water-insoluble particulate matter, with a metal oxide comprising: (a) contacting the solid, water-insoluble particulate matter with an ionic additive and an aqueous medium to obtain a dispersion of said particulate matter having positive charges on its surface; (b) subjecting the particulate matter to a coating procedure comprising precipitating a metal oxide salt onto the surface of the particulate matter to form a metal oxide layer thereon to thereby obtain particulate matter coated by a metal oxide coating layer; (c) repeating step (b) at least 4 more times; and (d) aging said coating layer. The invention further relates to particles comprising a particulate matter coated by a metal oxide layer, to a use of the particles for topical administration, and to a method for preventing, reducing, or eliminating pests at a locus, using the particles.

Claims

1. A process for coating a solid, water-insoluble particulate matter, with a metal oxide comprising:

(a) contacting the solid, water-insoluble particulate matter with an ionic additive and an aqueous medium to obtain a dispersion of said particulate matter having positive charges on its surface;

(b) subjecting the particulate matter to a coating procedure comprising precipitating a metal oxide salt onto the surface of the particulate matter to form a metal oxide layer thereon to thereby obtain particulate matter coated by a metal oxide coating layer;

(c) repeating step (b) at least 4 more times; and

(d) aging said coating layer.

3. The process of claim 1, comprising:

(a) contacting the solid, water-insoluble particulate matter, with a first cationic additive and an aqueous medium to obtain a dispersion of said particulate matter having positive charges on its surface;

(b) subjecting the particulate matter to a coating procedure comprising precipitating a metal oxide salt onto the surface of the particulate matter to form a metal oxide coating layer on the particulate matter;

(b1) in an aqueous medium, contacting the coated particulate matter with a surface adhering additive being one or both of (i) a second cationic additive, and (ii) a non-ionic additive;

(b2) subjecting the particulate matter obtained in step (b1) to a coating procedure as in step (b);

(c) repeating steps (b1) and (b2) at least 3 more times; and

(d) aging the metal oxide coating layer.

4. The process of claim 1, comprising:

(a) contacting the solid, water-insoluble particulate matter, with an anionic additive, a first cationic additive and an aqueous medium to obtain a dispersion of said particulate matter having positive charges on its surface;

(b) subjecting the particulate matter to a coating procedure comprising precipitating a metal oxide salt onto the surface of the particulate matter to form a metal oxide coating layer on the particulate matter;

(b1) in an aqueous medium, contacting the coated particulate matter with a surface adhering additive being one or both of (i) a second cationic additive, and (ii) a non-ionic additive;

(b2) subjecting the particulate matter obtained in step (b1) to a coating procedure as in step (b);

(c) repeating steps (b1) and (b2) at least 3 more times; and

(d) aging the metal oxide coating layer.

9. The process of claim 1, further comprising, following step (d):

(e) separating the coated particulate matter from the aqueous medium and optionally rinsing and re-dispersing the coated particulate matter in an aqueous medium.

15. The process of claim 1, wherein said particulate matter is a pharmaceutically, cosmetically, or agrochemical active ingredient.

24. The process of claim 3, wherein said cationic additive in step (a) is a cationic surfactant selected from monoalkylquaternary ammonium salts, dialkyl quaternary ammonium salts, and mixtures thereof.

27. The process of claim 1, wherein said ionic additive is selected from an anionic surfactant, a cationic polymer, and mixtures thereof.

37. The process according to claim 1 further comprising chemically modifying the surface of the coated particulate matter.

38. The process of claim 37, comprising attaching hydrophobic groups to the surface of the metal oxide layer.

40. The process according to claim 1 wherein the metal oxide coating layer of the coated particulate matter has a width of 0.1-10 micron.

41. Coated particulate matter obtained by the process according to claim 1.

42. The coated particulate matter of claim 41, wherein the weight ratio of the metal oxide to said particulate matter, is in the range of 1:

99 to 40;

60.

46. A method for treating a surface condition in a subject, comprising topically administering onto the surface a composition comprising a coated particulate matter according to claim 41 the particulate matter being a topically dermatologically active agent.

47. The method of claim 46, wherein said surface is skin or mucosal membrane.

48. The method of claim 47 wherein said surface condition is a disease or disorder selected from acne, infection, inflammation, puritis, psoriasis, seborrhea, contact dermatitis, rosacea, and a combination thereof.

49. The method of claim 46, wherein said metal oxide layer releases the particulate matter following said topical administration.

50. The method of claim 46, wherein said dermatologically active agent is benzoyl peroxide.

51. The method of claim 46, wherein said dermatologically active agent is a retinoid.

54. A method for preventing, reducing, or eliminating pests at a locus, comprising applying to the locus of said pest a pesticidaly effective amount of a pesticidal composition comprising a coated particulate matter according to claim 41, the particulate matter being a pesticide.

2. (canceled)

5-8. -8. (canceled)

10-14. -14. (canceled)

16-23. -23. (canceled)

25-26. -26. (canceled)

28-36. -36. (canceled)

39. (canceled)

43-44. -44. (canceled)

45. Particles comprising a particulate matter coated by a metal oxide layer wherein:

(i) said metal oxide layer has a width of 0.1-10 micron; and

(ii) said particles are characterized in that when tested in a Dissolution Tester using Paddle Method in a medium in which said particulate matter is soluble, and a dissolution volume in which the concentration of the particulate matter is lower than the solubility of the particulate matter, the time for releasing 50% w/w of the particulate matter from said particles is at least two-fold higher as compared to the dissolution of the free form of the particulate matter having substantially the same particle size diameter as the particulate matter in said particles.

52-53. -53. (canceled)

55-57. -57. (canceled)