Composition exhibiting enhanced formulation stability and delivery of topical active ingredients

• US 20020064541A1
• Filed: 10/23/2001
• Published: 05/30/2002
• Est. Priority Date: 04/21/2000
• Status: Active Grant

• Current Assignee: Sol-Gel Technologies Ltd.
• Original Assignee: Sol-Gel Technologies Ltd.
• Inventors: Magdassi, Shlomo, Rottman, Claudio, Lapidot, Noa, Seri-Levy, Alon, Gans, Orit, Avnir, David
• Granted Patent: US 7,758,888 B2
• Time in Patent Office: Days
• US Class Current: 424/401
• CPC Class Codes: A61K 2800/412 Microsized, i.e. having sizes between 0.1 and 100 microns
• CPC Class Codes: A61K 2800/75 Anti-irritant
• CPC Class Codes: A61K 8/042 Gels
• CPC Class Codes: A61K 8/11 Encapsulated compositions
• CPC Class Codes: A61K 8/25 Silicon; Compounds thereof
• CPC Class Codes: A61K 8/37 Esters of carboxylic acids
• CPC Class Codes: A61K 8/38 Percompounds, e.g. peracids
• CPC Class Codes: A61K 8/602 Glycosides, e.g. rutin
• 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 9/5031 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poly(lactide-co-glycolide)
• CPC Class Codes: A61K 9/5115 Inorganic compounds
• CPC Class Codes: A61K 9/5138 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• CPC Class Codes: A61P 17/06 Antipsoriatics
• CPC Class Codes: A61P 17/10 Anti-acne agents
• CPC Class Codes: A61P 29/00 Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
• CPC Class Codes: A61P 3/02 Nutrients, e.g. vitamins, minerals
• CPC Class Codes: A61P 31/04 Antibacterial agents
• CPC Class Codes: A61P 31/12 Antivirals
• CPC Class Codes: A61Q 1/00 Make-up preparations; Body powders; Preparations for removing make-up
• 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: A61Q 17/04 : Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
• CPC Class Codes: A61Q 19/00 : Preparations for care of the skin
• CPC Class Codes: A61Q 5/02 : Preparations for cleaning the hair
• CPC Class Codes: A61Q 5/12 : Preparations containing hair conditioners
• CPC Class Codes: B82Y 5/00 : Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery

Abstract

A therapeutic, cosmetic or cosmeceutic composition for topical application, capable of stabilizing an active ingredient and delivering the active ingredient, comprising a plurality of microcapsules having a core-shell structure. The microcapsules have a diameter of approximately 0.1 to 100 micron. The core of each microcapsule includes at least one active ingredient and is encapsulated within a microcapsular shell. The shell is comprised of at least one inorganic polymer obtained by a sol-gel process, and the shell protects the active ingredient before topical application and is designed to release the active ingredient from the microcapsules following application. The composition is useful in encapsulating active ingredients, such as benzoyl peroxide, that are unstable in other formulation, or are irritating to the skin.

Claims

1. A therapeutic, cosmetic or cosmeceutic composition for topical application comprising a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes at least one active ingredient whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process.

2. The composition of claim 1, designed to stabilize said at least one active ingredient prior to said topical application.

3. The composition of claim 1, designed to release said at least one active ingredient from said microcapsules following said topical application.

4. The composition of claim 2, designed to release said at least one active ingredient from said microcapsules following said topical application.

5. The composition of claim 1, wherein said microcapsules are characerized as non-scratching both prior and following disintegration.

6. The composition of claim 1, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

7. The composition of claim 1, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by said sol-gel process.

8. The composition of claim 1, comprising at least two different types of microcapsules each of said at least two different types of microcapsules containing a different active ingredient.

9. The composition of claim 1, further comprising a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

10. The composition of claim 9, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

11. The composition of claim 10, wherein said at least one non-encapsulated active ingredient and said at least one active ingredient are chemically reactive with one another.

12. The composition of claim 9, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

13. The composition of claim 9, further comprising an adjuvant within said acceptable carrier.

14. The composition of claim 13, wherein said adjuvant is selected from the group consisting of an anti-oxidant, a metal sequestering agent, a buffering agent and mixtures thereof.

15. The composition of claim 9, wherein said acceptable carrier comprises at least one member selected from the group consisting of a thickener, an emollient, an emulsifier, a humectant a surfactant, a suspending agent, a film forming agent, a foam building agent, a preservative, an antifoaming agent, a fragrance, a lower monoalcoholic polyol, a high boiling point solvent, a propellant, a colorant and a pigment.

16. The composition of claim 1, wherein a final form of said composition is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a suspension, a powder, an aerosol, a spray, a foam, a shampoo, a hair conditioner, a lacquer, a makeup, a solid stick and a toothpaste.

17. The composition of claim 9, wherein a final form of said composition is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a suspension, a powder, an aerosol, a spray, a foam, a shampoo, a hair conditioner, a lacquer, a makeup, a solid stick and a toothpaste.

18. The composition of claim 1, wherein said at least one active ingredient is selected from the group consisting of a vitamin, an anti-inflammatory agent, an analgestic, an anti-fungal agent, an anti-biotic, an anti-viral agent, an anti-acne agent, an anti histamine, an enzyme, a co-enzyme, a humectant, a dermatological agent, an insect repellent, a perfume, a color, a dye, a skin whitening agent, an aromatic oil, a flavoring agent, a dental agent and mixtures thereof.

19. The composition of claim 1, wherein an amount of said at least one active ingredient is between about 0.001% and about 95% by weight of said microcapsules.

20. The composition of claim 1, wherein said microcapsular core further includes an adjuvant selected from the group consisting of an anti-oxidant, a metal-sequestering agent, a buffering agent and mixtures thereof.

21. The composition of claim 1, wherein said microcapsular core is in a form of an emulsion.

22. The composition of claim 21, wherein said emulsion is an oil-in-water emulsion.

23. The composition of claim 1, wherein said microcapsular core is in a form selected from the group consisting of a solid, an oil solution, an aqueous solution and a dispersion.

24. The composition of claim 1, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof and mixtures thereof.

25. The composition of claim 18, wherein said vitamin is selected from the group consisting of vitamin C, an ester of vitamin C, a salt of vitamin C and mixtures thereof.

26. The composition of claim 25, further comprising a metal sequestering agent within said microcapsular core.

27. The composition of claim 26, wherein said metal sequestering agent is selected from the group consisting of ethylenediamine tetra acetic acid, hexamethylenediamine tetra acetic acid, ethylenediamine tetra(methylenephosphonic acid), diethylenetriamine penta(methylenephosphonic acid), or hexamethylenediamine tetra (methylene phosphonic acid), derivatives thereof, salts thereof and mixtures thereof.

28. The composition of claim 18 wherein said vitamin is a retinoid.

29. The composition of claim 29, further comprising an anti-oxidant within said microcapsular core.

30. The composition of claim 29, wherein said antioxidant is selected from the group consisting of BHT, BHA, vitamin E, vitamin E acetate, vitamin E palmitate, vitamin C, an ester of vitamin C, a salt of vitamin C and mixtures thereof.

31. The composition of claim 18 wherein said anti-acne agent or said dental agent is a peroxide selected from the group consisting of benzoyl peroxide and urea peroxide.

32. The composition of claim 31, further comprising an acceptable carrier including at least one non-encapsulated active ingredient whereas said non-encapsulated active ingredient is oxidized by said peroxide.

33. The composition of claim 32, wherein said non-encapsulated active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

34. The composition of claim 1, further comprising at least one ingredient selected from the group consisting of a polymer, a fatty acid, a fatty acid derivative, a surfactant, a polysaccharide, a protein, a polypeptide, an amino acid, and a mixture thereof, said ingredient is present within said microcapsular core or is attached to said microcapsular shell of said microcapsules.

35. The composition of claim 18, wherein said dental agent is selected from the group consisting of sodium perborate, sodium percarbonate and a mixture thereof.

36. The composition of claim 9, wherein said acceptable carrier comprises at least one auxiliary agent, said auxiliary agent triggers the release of said at least one active ingredient from said microcapsules upon said topical application.

37. The composition of claim 36, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

38. The composition of claim 1, further comprising an auxiliary vehicle, said auxiliary vehicle is added to the composition prior to said topical application to trigger the release of said at least one active ingredient from said microcapsules.

39. The composition of claim 38, wherein said auxiliary vehicle comprises at least one member selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

40. The composition of claim 1, wherein said microcapsules are designed to release said at least one active ingredient upon disintegration.

41. The composition of claim 40, wherein said disintegration is effectable by a rubbing or spreading action.

42. The composition of claim 40, wherein said disintegration is effecteable by drying.

43. The composition of claim 1, designed to release said at least one active ingredient upon extraction.

44. The composition of claim 8, wherein said composition releases each of said active ingredients at a different rate or as a result of a different action.

45. The composition of claim 44, wherein said action is selected from the group consisting of a rubbing or spreading action, drying, contacting said microcapsules with an auxiliary agent, extraction of an active ingredient and combinations thereof.

46. The composition of claim 45, wherein said auxiliary agent is selected from the group consisting of a surfactant an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

48. The system of claim 47, designed to release said at least one active ingredient from said microcapsules following said topical application.

49. The system of claim 47, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

50. The system of claim 47, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

51. The system of claim 47, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by a sol-gel process.

52. The system of claim 47, comprising at least two different types of microcapsules each of said at least two different types of microcapsules containing a different active ingredient.

53. The system of claim 47, comprising a first plurality of microcapsules encapsulating at least one active ingredient and a second plurality of microcapsules encapsulating at least one active ingredient, wherein said at least one active ingredient in said second plurality of microcapsules is different than said at least one active ingredient in said first plurality of microcapsules.

54. The system of claim 1, further comprising a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

55. The system of claim 54, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

56. The system of claim 55, wherein said at least one non-encapsulated active ingredient and said at least one active ingredient axe chemically reactive with one another.

57. The system of claim 54, wherein said acceptable crier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

58. The system of claim 54, further comprising an adjuvant within said acceptable carrier.

59. The system of claim 47, wherein said at least one active ingredient is selected from the group consisting of a vitamin, an anti-inflammatory agent, an analgestic, an anti-fungal agent, anti-biotic, an anti-viral agent, an anti-acne agent, an anti histamine, an enzyme, a co-enzyme, a humectant, a dermatological agent an insect repellent, a perfume, a color, a dye, a skin whitening agent, an aromatic oil, a flavoring agent a dental agent, and mixtures thereof.

60. The system of claim 47, wherein an amount of said at least one active ingredient is about 0.001% and about 95% by weight of said microcapsules.

61. The system of claim 47, wherein said core is in a form selected from the group consisting of an emulsion, a solid, an oil solution, an aqueous solution, and a dispersion.

62. The system of claim 47, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof, and a mixture thereof.

47. A system for enhancing a stability of at least one active ingredient in a therapeutic, cosmetic or cosmeceutic composition for topical application, the system comprising a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes at least one active ingredient, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, said system is designed to stabilize said at least one active ingredient prior to said topical application.

63. A system for releasing/delivering at least one active ingredient from a therapeutic, cosmetic or cosmeceutic composition for topical application, the system comprising a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes at least one active ingredient, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, said system is designed to release said at least one active ingredient from said microcapsules following said topical application.

64. The system of claim 63, designed to stabilize said at least one active ingredient prior to said topical application.

65. The system of claim 63, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

66. The system of claim 63, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

67. The system of claim 63, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by a sol-gel process.

68. The system of claim 63, comprising at least two different types of microcapsules each of said at least two different types of microcapsules containing a different active ingredient.

69. The system of claim 63, comprising a first plurality of microcapsules encapsulating at least one active ingredient and a second plurality of microcapsules encapsulating at least one active ingredient, wherein said at least one active ingredient in said second plurality of microcapsules is different than said at least one active ingredient in said first plurality of microcapsules.

70. The system of claim 63, further comprising a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

71. The system of claim 70, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

72. The system of claim 70, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

73. The system of claim 70, further comprising an adjuvant within said acceptable carrier.

74. The system of claim 63, wherein said at least one active ingredient is selected from the group consisting of a vitamin, an anti-inflammatory agent, an analgestic, an anti-fungal agent, an anti-biotic, an anti-viral agent, an anti-acne agent, an anti histamine, an enzyme, a co-enzyme, a humectant, a dermatological agent, an insect repellent, a perfume, a color, a dye, a skin whitening agent, an aromatic oil, a flavoring agent, a dental agent, and mixtures thereof.

75. The system of claim 63, wherein an amount of said at least one active ingredient is about 0.001% and about 95% by weight of said microcapsules.

76. The system of claim 63, wherein said core is in a form selected from the group consisting of an emulsion, a solid, an oil solution, an aqueous solution, and a dispersion.

77. The system of claim 63, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof, and a mixture thereof.

78. The system of claim 70, wherein said acceptable carrier comprises at least one auxiliary agent, said auxiliary agent triggers the release of said at least one active ingredient from said at least one plurality of microcapsules upon said topical application.

79. The system of claim 78, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

80. The system of claim 63, further comprising an auxiliary vehicle, said auxiliary vehicle is added to the composition prior to said topical application to trigger the release of said at least one active ingredient.

81. The system of claim 80, wherein said auxiliary vehicle comprises at least one member selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

82. The system of claim 63, wherein said releasing/delivering of said at least one active ingredient is effectable by disintegrating said microcapsules.

83. The system of claim 82, wherein said disintegrating is effectable by a rubbing or spreading action.

84. The system of claim 63, wherein said disintegrating is effecteable by drying.

85. The system of claim 63, wherein said releasing/delivering of said at least one active ingredient is effectable by extracting said active ingredient.

86. The system of claim 68, wherein said releasing/delivering of each of said different active ingredients is at a different rate.

87. The system of claim 68, wherein said releasing/delivering of each of said different active ingredients is effectable by a different action.

88. The system of claim 87, wherein said action is selected from the group consisting of a rubbing or spreading action, drying of said microcapsules, contacting said microcapsules with an auxiliary agent, extracting at least one of said active ingredients and combinations thereof.

89. The system of claim 88, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

90. A method of treating a skin, hair, ear, mucosal membrane, rectal, nasal or dental condition in a subject in need thereof, the method comprising topically applying onto a skin, hair, ear, mucosal membrane, rectum, nose or tooth a composition comprising a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes at least one active ingredient whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process.

91. The method of claim 90, wherein said composition is designed to stabilize said at least one active ingredient prior to said topical application.

92. The method of claim 90, wherein said composition is designed to release said at least one active ingredient from said microcapsules following said topical application.

93. The method of claim 91, wherein said composition is designed to release said at least one active ingredient from said microcapsules following said topical application.

94. The method of claim 90, wherein said skin, hair, ear, mucosal membrane, rectal, nasal or dental condition comprises a condition, disease or disorder selected from the group consisting of acne, psoriasis, seborrea, bacteria, virus, fungus, infection, inflammation, aging signs and dandroofs.

95. The method of claim 90, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

96. The method of claim 95, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

97. The method of claim 90, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by a sol-gel process.

98. The method of claim 90, wherein said composition comprising at least two different types of microcapsules each of said at least two different types of microcapsules containing a different active ingredient.

99. The method of claim 90, wherein said composition comprising a first plurality of microcapsules encapsulating at least one active ingredient and a second plurality of microcapsules encapsulating at least one active ingredient, wherein said at least one active ingredient in said second plurality of microcapsules is different than said at least one active ingredient in said first plurality of microcapsules.

100. The method of claim 90, wherein said composition further comprising a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

101. The method of claim 100, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

102. The method of claim 101, wherein said at least one non-encapsulated active ingredient and said at least one active ingredient are chemically reactive with one another.

103. The method of claim 100, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

104. The method of claim 100, wherein said composition her comprising an adjuvant within said acceptable carrier.

105. The method of claim 90, wherein said at least one active ingredient is selected from the group consisting of a vitamin, an anti-inflammatory agent, an analgestic, an anti-fungal agent, an anti-biotic, an anti-viral agent, an anti-acne agent, an anti histamine, an enzyme, a co-enzyme, a humectant, a dermatological agent, an insect repellent, a perfume, a color, a dye, a skin whitening agent, an aromatic oil, a flavoring agent, a dental agent, and mixtures thereof.

106. The method of claim 90, wherein an amount of said at least one active ingredient is about 0.001% and about 95% by weight of said microcapsules.

107. The method of claim 90, wherein said core is in a form selected from the group consisting of an emulsion, a solid, an oil solution, an aqueous solution, and a dispersion.

108. The method of claim 90, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof, and a mixture thereof.

109. A process for the preparation of microcapsules having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes at least one active ingredient, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, the process comprising:

(a) preparing a hydrophobic solution or a hydrophobic dispersion comprising at least one sol-gel precursor and at least one active ingredient to be encapsulated within said microcapsules;

(b) emulsifying said hydrophobic solution or dispersion in an aqueous solution under high shear forces, so as to obtain an emulsion; and

(c) mixing and stirring said emulsion, with a second aqueous solution, at a predetermined pH, so as to obtain said microcapsules.

110. The process of claim 109, wherein said emulsion is an oil-in-water emulsion.

111. The process of claim 110, wherein a concentration of said hydrophobic solution or dispersion in said emulsion is between 5% and 45% by weight.

112. The process of claim 109, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

113. The process of claim 112, wherein said diameter of said microcapsules is pre-determined by reaction conditions and/or a reaction ingredient selected from the group consisting of said shear forces, said sol-gel precursor, a composition of said aqueous solution, a composition of said second aqueous solution and combinations thereof.

114. The process of claim 109, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

115. The process of claim 109, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by said sol-gel process.

116. The process of claim 109, wherein said hydrophobic solution or dispersion further comprises a surfactant, a polymer, a polymeric surfactant, a suspending agent or mixtures thereof.

117. The process of claim 109, where said at least one sol-gel precursor is selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof and any mixture thereof.

118. The process of claim 109, wherein a concentration of said at least one active ingredient in said microcapsules is between about 1% and about 95% by weight.

119. The process of claim 109, wherein said hydrophobic dispersion is prepared by a method comprising:

wetting and mixing a solid active ingredient to be encapsulated within said microcapsules with at least one additive selected from the group consisting of a liquid, a wetting agent and a combination thereof; and

micronizing said solid active ingredient by grinding or milling, so as to obtain a micronized solid active ingredient.

120. The process of claim 119, wherein said wetting and mixing is prior to said micronizing.

121. The process of claim 119, wherein said micronizing is prior to said wetting and mixing.

122. The process of claim 119, further comprising adding and mixing at least one dispersing phase selected from the group consisting of an oil, a sol-gel precursor and a combination thereof, so as to obtain a dispersion of said solid active ingredient in said dispersing phase.

123. The process of claim 122, wherein a concentration of said solid active ingredient is between about 0.001% and about 95% by weight, based on the total weight of said solid and said dispersing phase.

124. The process of claim 119, wherein a concentration of said solid active ingredient in said dispersion is between about 1% and about 95% by weight.

125. The process of claim 119, wherein an average particle size of said solid active ingredient is between about 0.1 micron and about 20 microns.

126. The process of claim 122, wherein a concentration of said dispersing phase in the final dispersion is between about 5% and about 99% by weight.

127. The process of claim 119, wherein said liquid is selected from the group consisting of a hydrophobic liquid, a hydrophilic liquid, an aqueous liquid and mixtures thereof.

128. The process of claim 127, wherein said hydrophobic liquid is selected from the group consisting of an oil, a sol-gel precursor and a mixture thereof.

130. The process of claim 119, wherein said wetting agent is selected from the group consisting of a surfactant a polymeric surfactant and a mixture thereof.

131. The process of claim 119, wherein said wetting agent is a surfactant and a concentration of said surfactant in said dispersion ranges between about 0.1% and about 20% by weight.

132. The process of claim 131, wherein said surfactant is selected from the group consisting of an anionic surfactant a cationic surfactant an amphoteric surfactant, a nonionic surfactant and mixtures thereof.

133. The process of claim 132, wherein said polymeric surfactant is selected from the group consisting of an anionic polymeric surfactant, a cationic polymeric surfactant, an amphoteric polymeric surfactant, a nonionic polymeric surfactant and mixtures thereof.

134. The process according to claims 132, wherein said polymeric surfactant is selected from the group consisting of a hydrocarbon-based polymer, a silicone polymer and mixtures thereof.

135. The process of claim 134, wherein said hydrocarbon-based polymer includes at least one ionic or non-ionic functional group selected from the group consisting of a phosphate ester, a sulfate, a carboxylate, at sulfosuccinate, a sulfonate, a thiosulfonate, an amino propionate, a betaine, a phosphobetaine, an alkyl quaternary compound, an amido quaternary compound, an imidazoline quaternary compound, a carboxy quaternary compound, an alcohol aloxylate, an alkanolamide and an ester.

136. The process of claim 134, wherein said silicone polymer is selected from the group consisting of a silicone phosphate ester polymer, a silicone sulfate polymer, a silicone carboxylate polymer, a silicone sulfosuccinate polymer, a silicone sulfonate polymer, a silicone thiosulfate polymer, a silicone amphoteric polymer, a silicone betaine polymer, a silicone phosphobetaine polymer, a silicone alkyl quaternary polymer, a silicone quaternary polymer, a silicone imidazoline quaternary polymer, a silicone carboxy quaternary polymer, a dimethcone copolyol polymer, a silicone alkanolamide polymer, a silicone ester polymer and mixtures thereof.

137. The process of claim 122, wherein said oil is selected from a group consisting of mineral oil, dimethicone, cyclomethicone, alkyl siloxanes, alkylether siloxanes, dimethicone copolyols, C12-15 alkyl benzoate, isostearyl benzoate, PPG-15 stearyl ether benzoate, octyldodecyl benzoate, stearyl benzoate, methyl gluceth-20 benzoate, poloxamer 182 dibenzoate, poloxamer 105 benzoate, transcutol, bernel ester, diethylhexylmaleate, diethylhexylsebacate, diethylhexyladipate, diisopropyladipate, diisopropylsebacate, diisopropylmaleate, ethylhexylsalicylate, tridecylsalicylate, butiloctylsalicylate, isopropylmyristate and mixtures thereof.

139. The process of claim 138, wherein a concentration of said hydrophobic solution or dispersion in said oil-in-water emulsion is between 5% and 45% by weight.

140. The process of claim 138, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

141. The process of claim 140, wherein said diameter of said microcapsules is pre-determined by reaction conditions and/or a reaction ingredient selected from the group consisting of said shear forces, said sol-gel precursor, a composition of said aqueous solution, a composition of said second aqueous solution and combinations thereof.

142. The process of claim 138, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

143. The process of claim 138, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by said sol-gel process.

144. The process of claim 138, wherein said hydrophobic solution or dispersion further comprises a surfactant, a polymer, a polymeric surfactant, a suspending agent or mixtures thereof.

145. The process of claim 138, wherein said at least one sol-gel precursor is selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof and any mixture thereof.

146. The process of claim 138, wherein a concentration of said at least one active ingredient in said microcapsules is between about 1% and about 95% by weight.

147. The process of claim 138, wherein said hydrophobic dispersion is prepared by a method comprising:

wetting and mixing a solid active ingredient to be encapsulated within said microcapsules with at least one additive selected from the group consisting of a liquid, a wetting agent and a combination thereof; and

micronizing said solid active ingredient by grinding or milling, so as to obtain a micronized solid active ingredient.

148. The process of claim 147, wherein said wetting and mixing is prior to said micronizing.

149. The process of claim 147, wherein said micronizing is prior to said wetting and mixing.

150. The process of claim 147, further comprising adding and mixing at least one dispersing phase selected from the group consisting of an oil, a sol-gel precursor and a combination thereof, so as to obtain a dispersion of said solid active ingredient in said dispersing phase.

151. The process of claim 150, wherein a concentration of said solid active ingredient is between about 0.001% and about 95% by weight, based on the total weight of said solid and said dispersing phase.

152. The process of claim 147, wherein a concentration of said solid active ingredient in said dispersion is between about 1% and about 95% by weight.

153. The process of claim 147, wherein an average particle size of said solid active ingredient is between about 0.1 micron and about 20 microns.

154. The process of claim 150, wherein a concentration of said dispersing phase in the final dispersion is between about 5% and about 99% by weight.

155. The process of claim 147, wherein said liquid is selected from the group consisting of a hydrophobic liquid, a hydrophilic liquid, an aqueous liquid and mixtures thereof.

156. The process of claim 155, wherein said hydrophobic liquid is selected from the group consisting of an oil, a sol-gel precursor and a mixture thereof.

157. The process of claim 155, wherein said hydrophilic liquid is glycerol and further wherein said aqueous liquid is water.

158. The process of claim 147, wherein said wetting agent is selected from the group consisting of a surfactant, a polymeric surfactant and a mixture thereof.

159. The process of claim 147, wherein said wetting agent is a surfactant and a concentration of said surfactant in said dispersion ranges between about 0.1% and about 20% by weight.

160. The process of claim 159, wherein said surfactant is selected from the group consisting of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and mixtures thereof.

161. The process of claim 150, wherein said oil is selected from a group consisting of mineral oil, dimethicone, cyclomethicone, alkyl siloxanes, alkylether siloxanes, dimethicone copolyols, C12-15 alkyl benzoate, isostearyl benzoate, PPG-15 stearyl ether benzoate, octyldodecyl benzoate, stearyl benzoate, methyl gluceth-20 benzoate, poloxamer 182 dibenzoate, poloxamer 105 benzoate, transcutol, bernel ester, diethylhexylmaleate, diethylhexylsebacate, diethylhexyladipate, diisopropyladipate, diisopropylsebacate, diisopropylmaleate, ethylhexylsalicylate, tridecylsalicylate, butiloctylsalicylate, isopropylmyristate and mixtures thereof.

163. The method of claim 162, wherein said composition is designed to stabilize said active ingredient prior to said delivering.

164. The method of claim 162, wherein said delivering of said active ingredient is time-controlled.

165. The method of claim 162, wherein said composition further comprises a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

166. The method of claim 162, wherein said disintegrating is effectable by a rubbing or spreading action.

167. The method of claim 162, wherein said disintegrating is effectable by electrostatic interactions.

168. The method of claim 162, wherein said disintegrating is effectable by drying.

169. The method of claim 168, wherein said drying is effectable by heating.

170. The method of claim 165, wherein said disintegrating is effectable by drying and said drying is effectable by an evaporation of at least a portion of said acceptable carrier upon said topical application.

171. The method of claim 162, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

172. The method of claim 162, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

173. The method of claim 162, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by a sol-gel process.

174. The method of claim 162, wherein said composition comprises at least two different types of microcapsules each of said at least two different types of microcapsules containing a different active ingredient.

175. The method of claim 165, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

176. The method of claim 165, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a suspension and a powder.

177. The method of claim 165, wherein said composition further comprises an adjuvant within said acceptable carrier.

178. The method of claim 162, wherein said at least one active ingredient is selected from the group consisting of a vitamin, an anti-inflammatory agent, an analgestic, an anti-fungal agent, an anti-biotic, an anti-viral agent, an anti-acne agent, an anti histamine, an enzyme, a co-enzyme, a humectant, a dermatological agent an insect repellent, a perfume, a color, a dye, a skin whitening agent, an aromatic oil, a flavoring agent, a dental agent, and mixtures thereof.

179. The method of claim 162, wherein an amount of said at least one active ingredient is about 0.001% and about 95% by weight of said microcapsules.

180. The method of claim 162, wherein said core is in a form selected from the group consisting of an emulsion, a solid, an oil solution, an aqueous solution, and a dispersion.

181. The method of claim 180, wherein said emulsion is an oil-in-water emulsion.

182. The method of claim 162, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof, and a mixture thereof.

183. The method of claim 174, wherein said delivering of each of said active ingredients is at a different rate or as a result of a different action.

185. The method of claim 184, wherein said composition is designed to stabilize said active ingredient prior to said delivering.

186. The method of claim 184, wherein said delivering of said active ingredient is time-controlled.

187. The method of claim 184, wherein said composition carrier comprises a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

188. The method of claim 184, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

189. The method of claim 184, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by a sot-gel process.

190. The method of claim 184, wherein said composition comprises at least two different types of microcapsules each of said at least two different types of microcapsules containing a different active ingredient.

191. The method of claim 187, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

192. The method of claim 187, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

193. The method of claim 187, wherein said composition further comprises an adjuvant within said acceptable carrier.

194. The method of claim 184, wherein said at least one active ingredient is selected from the group consisting of a vitamin, an anti-inflammatory agent, an analgestic, an anti-fungal agent, a anti-biotic, an anti-viral agent an anti-acne agent, an anti histamine, an enzyme, a co-enzyme, a humectant, a dermatological agent, an insect repellent a perfume, a color, a dye, a skin whitening agent an aromatic oil, a flavoring agent, a dental agent, and mixtures thereof.

195. The method of claim 184, wherein an amount of said at least one active ingredient is about 0.001% and about 95% by weight of said microcapsules.

196. The method of claim 184, wherein said core is in a form selected from the group consisting of an emulsion, a solid, an oil solution, an aqueous solution and a dispersion.

197. The method of claim 196, wherein said emulsion is an oil-in-water emulsion.

198. The method of claim 184, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof, and a mixture thereof.

199. The method of claim 190, wherein said delivering of each of said active ingredients is at a different rate or as a result of a different action.

200. The method of claim 184, wherein said extracting is effectable by contacting said composition with a moisture, an electrolyte, a surfactant, a buffering agent or mixtures thereof.

201. The method of claim 193, wherein said moisture and said electrolyte are present in a body fluid.

202. The method of claim 200, wherein said moisture, said electrolyte, said surfactant, said buffering agent or said mixtures thereof are added to said composition prior to said topical application.

203. The method of claim 187, wherein said extracting is effectable by at least a portion of said acceptable carrier.

204. The method of claim 203, wherein said acceptable carrier comprises a mixture of water and an auxiliaty agent and said extracting is effected by said auxiliary agent after said water evaporates upon said topical application.

205. The method of claim 203, wherein said acceptable carrier comprises an auxilary agent and said extracting is effectable by said auxiliary agent.

206. The method of claim 204, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

207. The method of claim 198, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a bufferin agent, a high boiling point solvent and mixtures thereof.

129. The process of cl 127, wherein said hydrophilic liquid is glycerol and further wherein said aqueous liquid is water.

138. A process for the preparation of microcapsules having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell in a form of an oil-in-water emulsion and includes at least one active ingredient, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, the process comprising:

(a) preparing a hydrophobic solution or a hydrophobic dispersion comprising at least one sol-gel precursor and at least one active ingredient to be encapsulated within said microcapsules;

(b) emulsifying said hydrophobic solution or dispersion in an aqueous solution under high shear forces, so as to obtain an oil-in-water emulsion; and

(c) mixing and stirring said oil-in-water emulsion, with a second aqueous solution, at a predetermined pH, so as to obtain said microcapsules.

162. A method of delivering an active ingredient from a therapeutic, cosmetic or cosmeceutic composition for topical application, the composition comprises a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes said active ingredient, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, the method comprising disintegrating said microcapsules upon said topical application.

184. A method of delivering an active ingredient from a therapeutic, cosmetic or cosmeceutic composition for topical application, the composition comprises a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes said active ingredient, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, the method comprising extracting said active ingredient upon said topical application.

208. A therapeutic, cosmetic or cosmeceutic composition for topical application comprising, as an active ingredient, benzoyl peroxide encapsulated in a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes said benoyl peroxide, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process.

209. The composition of claim 208, designed to stabilize said benzoyl peroxide prior to said topical application.

210. The composition of claim 208, designed to release said benzoyl peroxide from said microcapsules following said topical application.

211. The composition of claim 209, designed to release said benzoyl peroxide from said microcapsules following said topical application.

212. The composition of claim 208, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

213. The composition of claim 208, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

214. The composition of claim 208, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by said sol-gel process.

215. The composition of claim 208, further comprising at least one different type of microcapsules, each of said at least one different type of microcapsules contain at least one active ingredient other than benzoyl peroxide.

216. The composition of claim 215, wherein said active ingredient and said benzoyl peroxide are chemically reactive with one another.

217. The composition of claim 215, wherein said at least one active ingredient is selected from the group consisting of erythromycin, synthomycin clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

218. The composition of claim 208, further comprising a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

219. The composition of claim 218, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

220. The composition of claim 219, wherein said at least one non-encapsulated active ingredient and said benzoyl peroxide are chemically reactive with one another.

221. The composition of claim 220, wherein said non-encapsulated active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

222. The composition of claim 218, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

223. The composition of claim 218, further comprising an adjuvant within said acceptable carrier.

224. The composition of claim 208, wherein an amount of said benzoyl peroxide is between about 0.001% and about 95% by weight of said microcapsules.

225. The composition of claim 208, wherein said microcapsular core is in a form of an emulsion.

226. The composition of claim 225, wherein said emulsion is an oil-in-water emulsion.

227. The composition of claim 208, wherein said microcapsular core is in a form selected from the group consisting of a solid, an oil solution, an aqueous solution and a dispersion.

228. The composition of claim 208, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_nP)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof and mixtures thereof.

229. The composition of claim 218, wherein said acceptable carrier comprises at least one auxiliary agent said auxiliary agent triggers the release of said benzoyl peroxide from said microcapsules upon said topical application.

230. The composition of claim 229, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

231. The composition of claim 208, further comprising an auxiliary vehicle, said auxiliary vehicle is added to the composition prior to said topical application to trigger the release of said benzoyl peroxide from said microcapsules.

232. The composition of claim 231, wherein said auxiliary vehicle comprises at least one member selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

233. The composition of claim 208, wherein said microcapsules are designed to release said benzoyl peroxide upon disintegration.

234. The composition of claim 233, wherein said disintegration is effectable by a rubbing or spreading action.

235. The composition of claim 233, wherein said disintegration is effecteable by drying.

236. The composition of claim 208, designed to release said benzoyl peroxide upon extraction.

238. The system of claim 237, designed to release said benzoyl peroxide from said microcapsules following said topical application.

239. The system of claim 237, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

240. The system of claim 237, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by said sol-gel process.

241. The system of claim 237, further comprising at least one different type of microcapsules, each of said at least one different type of microcapsules containing an active ingredient other than benzoyl peroxide.

242. The system of claim 241, wherein said active ingredient and said benzoyl peroxide are chemically reactive with one another.

243. The system of claim 241, wherein said active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

244. The system of claim 237, further comprising a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

245. The system of claim 244, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

246. The system of claim 245, wherein said at least one non-encapsulated active ingredient and said benzoyl peroxide are chemically reactive with one another.

247. The system of claim 246, wherein said non-encapsulated active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

248. The system of claim 244, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

249. The system of claim 244, further comprising an adjuvant within said acceptable carrier.

250. The system of claim 237, wherein an amount of said benzoyl peroxide is between about 0.001% and about 95% by weight of said microcapsules.

251. The system of claim 237, wherein said microcapsular core is in a form of an emulsion.

252. The system of claim 251, wherein said emulsion is an oil-in-water emulsion.

253. The system of claim 237, wherein said microcapsular core is in a form selected from the group consisting of a solid, an oil solution, an aqueous solution and a dispersion.

254. The system of claim 237, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof and mixtures thereof.

256. The system of claim 255, designed to stabilize said benzoyl peroxide prior to said topical application.

257. The system of claim 255, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

258. The system of claim 255, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by said sol-gel process.

259. The system of claim 255, further comprising at least one different type of microcapsules, each of said at least one different type of microcapsules containing at least one active ingredient other than benzoyl peroxide.

260. The system of claim 259, wherein said active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

261. The system of claim 255, further comprising a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

262. The system of claim 261, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

263. The system of claim 262, wherein said at least one non-encapsulated active ingredient and said benzoyl peroxide are chemically reactive with one another.

264. The system of claim 263, wherein said non-encapsulated active ingredient is selected from the group consist of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

265. The system of claim 261, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

266. The system of claim 261, her comprising an adjuvant within said acceptable carrier.

267. The system of claim 255, wherein an amount of said benzoyl peroxide is between about 0.001% and about 95% by weight of said microcapsules.

268. The system of claim 255, wherein said microcapsular core is in a form of an emulsion.

269. The system of claim 268, wherein said emulsion is an oil-in-water emulsion.

270. The system of claim 255, wherein said microcapsular core is in a form selected from the group consisting of a solid, an oil solution, an aqueous solution and a dispersion.

271. The system of claim 255, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof and mixtures thereof.

272. The system of claim 261, wherein said acceptable carrier comprises at least one auxilary agent, said auxiliary agent triggers the release of said benzoyl peroxide from said microcapsules upon said topical application.

273. The system of claim 272, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

274. The system of claim 255, further comprising an auxiliary vehicle, said auxiliary vehicle is added to said system prior to said topical application to trigger the release of said benzoyl peroxide from said microcapsules.

275. The system of claim 274, wherein said auxiliary vehicle comprises at least one member selected from the group consisting of a surfactant, an electrolyte, a buffering agent a high boiling point solvent and mixtures thereof.

276. The system of claim 255, wherein said releasing/delivering of said benzoyl peroxide is effectable by disintegrating said microcapsules.

277. The system of claim 276, wherein said disintegrating is effectable by a rubbing or spreading action.

278. The system of claim 276, wherein said disintegrating is effecteable by drying.

279. The system of claim 255, wherein said releasing/delivering of said benzoyl peroxide is effectable by extraction.

280. The system of claim 259, wherein said releasing/delivering of said benzoyl peroxide and said releasing/delivering of said active ingredient other than benzoyl peroxide are at a different rate.

281. The system of claim 259, wherein said releasing/delivering of said benzoyl peroxide and said releasing/delivering of said active ingredient other than benzoyl peroxide are effectable by a different action.

282. The system of claim 281, wherein said action is selected from the group consisting of a rubbing or spreading action, drying of said microcapsules, contacting said microcapsules with an auxiliary agent, extracting and combinations thereof.

283. The system of claim 282, wherein said auxiliary agent is selected from the group consisting of a surfactant an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

285. The method of claim 284, wherein said composition is designed to stabilize said benzoyl peroxide prior to said topical application.

286. The method of claim 284, wherein said composition is designed to release said benzoyl peroxide from said microcapsules following said topical application.

287. The method of claim 285, wherein said composition is designed to release said benzoyl peroxide from said microcapsules following said topical application.

288. The method of claim 284, wherein said skin or dental condition comprises a condition, disease or disorder selected from the group consisting of acne, psoriasis, seborrea, bacteria, virus, fungus, infection, inflammation and cavity.

289. The method of claim 284, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

290. The method of claim 284, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

291. The method of claim 284, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by a sot-gel process.

292. The method of claim 284, wherein said composition further comprising at least one different type of microcapsules, each of said at least different type of microcapsules containing at least one active ingredient other than benzoyl peroxide.

293. The method of claim 292, wherein said at least one active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

294. The method of claim 284, wherein said composition further comprising a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

295. The method of claim 294, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

296. The method of claim 295, wherein said at least one non-encapsulated active ingredient and said benzoyl peroxide are chemically reactive with one another.

297. The method of claim 296, wherein said non-encapsulated active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

298. The method of claim 294, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a suspension and a powder.

299. The method of claim 294, further comprising an adjuvant within said acceptable carrier.

300. The method of claim 284, wherein an amount of said at least one active ingredient is about 0.001% and about 95% by weight of said microcapsules.

301. The method of claim 284, wherein said core is in a form selected from the group consisting of an emulsion, a solid, an oil solution, an aqueous solution, and a dispersion.

302. The method of claim 301, wherein said emulsion is an oil-in-water emulsion.

303. The method of claim 284, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof, and a mixture thereof.

237. A system for enhancing a stability of benzoyl peroxide in a therapeutic, cosmetic or cosmeceutic composition for topical application, said system comprising a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes said benzoyl peroxide, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, said microcapsular shell stabilizes and protects said benzoyl peroxide prior to said topical application.

255. A system for releasing/delivering benzoyl peroxide from a therapeutic, cosmetic or cosmeceutic composition for topical application, said system comprising a plurality of microcapsules having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes benzoyl peroxide, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, said system releases said benzoyl peroxide from said composition following said topical application.

284. A method of treating a skin or dental condition in a subject in need thereof, the method comprising topically applying onto said skin, oral cavity or tooth a composition comprising benzoyl, peroxide as an active ingredient encapsulated in a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes said benzoyl peroxide, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process.

304. A process for encapsulating benzoyl peroxide in microcapsules having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes said benzoyl peroxide, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, the process comprising:

(a) preparing a hydrophobic solution or a hydrophobic dispersion comprising at least one sol-gel precursor and benzoyl peroxide;

(b) emulsifying said hydrophobic solution or dispersion in an aqueous solution under high shear forces, so as to obtain an emulsion containing said benzoyl peroxide; and

(c) mixing and stirring said emulsion, with a second aqueous solution, at a selected pH, so as to obtain said benzoyl peroxide encapsulated in said microcapsules.

305. The process of claim 304, wherein said emulsion is an oil-in-water emulsion.

306. The process of claim 305, wherein a concentration of said hydrophobic solution or dispersion in said emulsion is between 5% and 45% by weight.

307. The process of claim 304, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

308. The process of claim 307, wherein said diameter of said microcapsules is pre-determined by reaction conditions and/or a reaction ingredient selected from the group consisting of said shear forces, said sol-gel precursor, a composition of said aqueous solution, a composition of said second aqueous solution and combinations thereof.

309. The process of claim 304, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

310. The process of claim 304, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by said sol-gel process.

311. The process of claim 304, wherein said hydrophobic solution or dispersion further comprises a surfactant, a polymer, a polymeric surfactant, a suspending agent or mixtures thereof.

312. The process of claim 304, wherein said at least one sol-gel precursor is selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof and any mixture thereof.

313. The process of claim 304, wherein a concentration of benzoyl peroxide in said microcapsules is between about 1% and about 95% by weight.

314. The process of claim 304, wherein said hydrophobic dispersion is prepared by a method comprising:

wetting and nixing said benzoyl peroxide to be encapsulated within said microcapsules with at least one additive selected from the group consisting of a liquid, a wetting agent and a combination thereof; and

micronizing said benzoyl peroxide by grinding or milling, so as to obtain a micronized benzoyl peroxide.

315. The process of claim 314, wherein said wetting and mixing is prior to said micronizing.

316. The process of claim 314, wherein said micronizing is prior to said wetting and mixing.

317. The process of claim 314, further comprising adding and mixing at least one dispersing phase selected from the group consisting of an oil, a sol-gel precursor and a combination thereof, so as to obtain a dispersion of said benzoyl peroxide in said dispersing phase.

318. The process of claim 317, wherein a concentration of benzoyl peroxide is between about 0.001% and about 95% by weight, based on the total weight of said benzoyl peroxide and said dispersing phase.

319. The process of claim 314, wherein a concentration of said benzoyl peroxide in said dispersion is between about 1% and about 95% by weight.

320. The process of claim 314, wherein an average particle size of said benzoyl peroxide is between about 0.1 micron and about 20 microns.

321. The process of claim 317, wherein a concentration of said dispersing phase in the final dispersion is between about 5% and about 99% by weight.

322. The process of claim 314, wherein said liquid is selected from the group consisting of a hydrophobic liquid, a hydrophilic liquid, an aqueous liquid and mixtures thereof.

323. The process of claim 322, wherein said hydrophobic liquid is selected from the group consisting of an oil, a sol-gel precursor and a mixture thereof.

324. The process of claim 322, wherein said hydrophilic liquid is glycerol and further wherein said aqueous liquid is water.

325. The process of claim 314, wherein said wetting agent is selected from the group consisting of a surfactant, a polymeric surfactant and a mixture thereof.

326. The process of claim 314, wherein said wetting agent is a surfactant and a concentration of said surfactant in said dispersion ranges between about 0.1% and about 20% by weight.

327. The process of claim 326, wherein said surfactant is selected from the group consisting of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and mixtures thereof.

328. The process of claim 327, wherein said polymeric surfactant is selected from the group consisting of an anionic polymeric, surfactant, a cationic polymeric surfactant an amphoteric polymeric surfactant, a nonionic polymeric surfactant and mixtures thereof.

329. The process according to claims 327, wherein said polymeric surfactant is selected from the group consisting of a hydrocarbon-based polymer, a silicone polymer and mixtures thereof.

330. The process of claim 329, wherein said hydrocarbon-based polymer includes at least one ionic or non-ionic functional group selected from the group consisting of a phosphate ester, a sulfate, a carboxylate, a sulfosuccinate, a sulfonate, a thiosulfonate, an amino propionate, a betaine, a phosphobetaine, an alkyl quaternary compound, an amido quaternary compound, an imidazoline quaternary compound, a carboxy quaternary compound, an alcohol aloxylate, an alkanolamide and an ester.

331. The process of claim 329, wherein said silicone polymer is selected from the group consisting of a silicone phosphate ester polymer, a silicone sulfate polymer, a silicone carboxylate polymer, a silicone sulfosuccinate polymer, a silicone sulfonate polymer, a silicone thiosulfate polymer, a silicone amphoteric polymer, a silicone betaine polymer, a silicone phosphobetaine polymer, a silicone alkyl quaternary polymer, a silicone quaternary polymer, a silicone imidazoline quaternary polymer, a silicone carboxy quaternary polymer, a dimethcone copolyol polymer, a silicone alkanolamide polymer, a silicone ester polymer and mixtures thereof.

332. The process of claim 317, wherein said oil is selected from a group consisting of mineral oil, dimethicone, cyclomethicone, alkyl siloxanes, alkylether siloxanes, dimethicone copolyols, C12-15 alkyl benzoate, isostearyl benzoate, PPG-15 stearyl ether benzoate, octyldodecyl benzoate, stearyl benzoate, methyl gluceth-20 benzoate, poloxamer 182 dibenzoate, poloxamer 105 benzoate, transcutol, bernel ester, diethylhexylmaleate, diethylhexylsebacate, diethylhexyladipate, diisopropyladipate, diisopropylsebacate, diisopropylmaleate, ethylhexylsalicylate, tridecylsalicylate, butiloctylsalicylate, isopropylmyristate and mixtures thereof.

333. A method of delivering benzoyl peroxide from a therapeutic, cosmetic or cosmeceutic composition for topical application, the composition comprises a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes said benzoyl peroxide, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sot-gel process, the method comprising disintegrating said microcapsules upon said topical application.

334. The method of claim 333, wherein said composition is designed to stabilize said benzoyl peroxide prior to said delivering.

335. The method of claim 333, wherein said delivering of said benzoyl peroxide is time-controlled.

336. The method of claim 333, wherein said composition further comprises a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

337. The method of claim 333, wherein said disintegrating is effectable by a rubbing or spreading action.

338. The method of claim 333, wherein said disintegrating is effectable by electrostatic interactions.

339. The method of claim 333, wherein said disintegrating is effectable by drying.

340. The method of claim 339, wherein said drying is effectable by heating.

341. The method of claim 336, wherein said disintegrating is effectable by drying and said drying is effectable by an evaporation of at least a portion of said acceptable carrier upon said topical application.

342. The method of claim 333, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

343. The method of claim 342, wherein said microcapsules are characterized as non-scratching both prior and following disintegration.

344. The method of claim 333, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by a sol-gel process.

345. The method of claim 336, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

346. The method of claim 345, wherein said non-encapsulated active ingredient and said benzoyl peroxide are chemically reactive within one another.

347. The method of claim 346, wherein said non-encapsulated active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

348. The method of claim 336, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

349. The method of claim 336, wherein said composition further comprises an adjuvant within said acceptable carrier.

350. The method of claim 333, wherein an amount of said benzoyl peroxide is about 0.001% and about 95% by weight of said microcapsules.

351. The method of claim 333, wherein said core is in a form selected from the group consisting of an emulsion, a solid, an oil solution, an aqueous solution, and a dispersion.

352. The method of claim 351, wherein said emulsion is an oil-in-water emulsion.

353. The method of claim 333, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof, and a mixture thereof.

355. The method of claim 354, wherein said composition is designed to stabilize said benzoyl peroxide prior to said delivering.

356. The method of claim 354, wherein said delivering of said benzoyl peroxide is time-controlled.

357. The method of claim 354, wherein said composition further comprises a pharmaceutically, cosmetically or cosmeceutically acceptable carrier.

358. The method of claim 354, wherein said microsapsules have an average diameter between 0.1 micron and 100 microns.

359. The method of claim 354, wherein said at least one inorganic polymer comprises at least one organically-modified inorganic polymer prepared by a sol-gel process.

360. The method of claim 357, wherein said acceptable carrier comprises at least one non-encapsulated active ingredient.

361. The method of claim 360, wherein said non-encapsulated active ingredient and said benzoyl peroxide are chemically reactive with one another.

362. The method of claim 361, wherein said non-encapsulated active ingredient is selected from the group consisting of erythromycin, synthomycin, clindamycin, tetracycline, a retinoid, an alpha hydroxy acid, a salt thereof, a derivative thereof and mixtures thereof.

363. The method of claim 357, wherein said acceptable carrier is selected from the group consisting of an emulsion, a cream, an aqueous solution, an oil, an ointment, a paste, a gel, a lotion, a milk, a foam, a suspension and a powder.

364. The method of claim 357, wherein said composition further comprises an adjuvant within said acceptable carrier.

365. The method of claim 354, wherein an amount of said benzoyl peroxide is about 0.001% and about 95% by weight of said microcapsules.

366. The method of claim 354, wherein said core is in a form selected from the group consisting of an emulsion, a solid, an oil solution, an aqueous solution, and a dispersion.

367. The method of claim 366, wherein said emulsion is an oil-in-water emulsion.

368. The method of claim 354, wherein said inorganic polymer is prepared from a sol-gel precursor selected from the group consisting of a metal alkoxide monomer, a semi-metal alkoxide monomer, a metal ester monomer, a semi-metal ester monomer, a silazane monomer, a monomer of the formula M(R)_n(P)_m, wherein M is a metallic or a semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent and m is and integer from 0 to 6, a partially hydrolyzed and partially condensed polymer thereof, and a mixture thereof.

369. The method of claim 354, wherein said extracting is effectable by contacting said composition with a moisture, an electrolyte, a surfactant, a buffering agent or mixtures thereof.

370. The method of claim 369, wherein said moisture and said electrolyte are present in a body fluid.

371. The method of claim 369, wherein said moisture, said electrolyte, said surfactant, said buffering agent or said mixtures thereof are added to said composition prior to said topical application.

372. The method of claim 357, wherein said extracting is effectable by at least a portion of said acceptable carrier.

373. The method of claim 372, wherein said acceptable carrier comprises a mixture of water and an auxiliaty agent and said extracting is effected by said auxiliary agent after said water evaporates upon said topical application.

374. The method of claim 372, wherein said acceptable carrier comprises an auxilary agent and said extracting is effectable by said auxiliary agent.

375. The method of claim 373, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a buffering agent, a high boiling point solvent and mixtures thereof.

376. The method of claim 374, wherein said auxiliary agent is selected from the group consisting of a surfactant, an electrolyte, a buffering agent a high boiling point solvent and mixtures thereof.

354. A method of delivering benzoyl peroxide from a therapeutic, cosmetic or cosmeceutic composition for topical application, the composition comprises a plurality of microcapsules each having a core-shell structure, wherein said core is a microcapsular core encapsulated within said shell and includes said benzoyl peroxide, whereas said shell is a microcapsular shell and includes at least one inorganic polymer obtained by a sol-gel process, the method comprising extracting said benzoyl peroxide upon said topical application.