Resumen
PCT No. PCT/IL98/00021 Sec. 371 Date Jul. 15, 1999 Sec. 102(e) Date Jul. 15, 1999 PCT Filed Jan. 15, 1998 PCT Pub. No. WO98/31333 PCT Pub. Date Jul. 23, 1998The present invention relates to sunscreen-doped sol-gel materials useful for protecting body tissues, such as skin, nails and hair and other surfaces from sunlight radiation. The sol-gel matrices are transparent to the UV radiation in the range above 250 nm and the doped sunscreen agents are either chemical or physical sunscreens capable of absorbing the UV radiation in the range above 250 nm. Any sunscreen molecule, moiety or particle may be used in the present invention. The sol-gel matrices may be particles in any shape, 0.01-100 microns in diameter, or they may be thin films, thin coatings or in the form of a monolith. The present invention also relates to a method for the preparation of sunscreen-doped sol-gel materials comprising condensation-polymerizing of at least one monomer selected from metal alkoxides, semi metal alkoxides, metal esters, semi metal esters and from monomers of the formula M(R)n(P)m, wherein M is a metallic or semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent or a sunscreening moiety or derivative and m is an integer from 0 to 6, in the presence of at least one sunscreen ingredient, resulting in the entrapment of the sunscreen ingredients within the formed sol-gel matrix.
Reivindicaciones
1. Sunscreen-doped sol-gel materials useful for protecting body tissues selected from skin, nails and hair from sunlight radiation, wherein the doped sunscreen materials are chemical sunscreen molecules capable of absorbing UV radiation in the range above 250 nm. 2. Sunscreen-doped sol-gel materials according to claim 1 wherein the chemical sunscreens are selected from para amino benzoates, salicylates, cinnamates, benzophenones, anthranilates, dibenzoylmethanes, camphores. 3. Sunscreen-doped sol-gel materials according to claim 1 wherein the sol-gel matrices of said sol-gel materials are transparent to the UV radiation in the range above 250 nm, covering the UVA and UVB regions. 4. Sunscreen-doped sol-gel materials according to claim 1 wherein the sol-gel matrices of said sol-gel materials are particles, either dried or dispersed as a sol. 5. Sunscreen-doped sol-gel materials according to claim 4 wherein the particles are 0.01 - 100 microns in diameter. 6. Sunscreen-doped sol-gel materials according to claim 4 wherein the sol-gel particles are spherically shaped. 7. Sunscreen-doped sol-gel materials according to claim 1 wherein the sol-gel matrices of said sol-gel materials are thin films or thin coatings. 8. Sunscreen-doped sol-gel materials according to claim 1 wherein the sol-gel matrices of said sol-gel materials are in the form of a monolith. 9. A method for the preparation of sunscreen-doped sol-gel materials comprising condensation - polymerizing of at least one monomer selected from metal alkoxides, semi metal alkoxides, metal esters, semi metal esters and from monomers of the formula M(R)n(P)m, wherein M is a metallic or semi metallic element, R is a hydrolyzable substituent, n is an integer from 2 to 6, P is a non polymerizable substituent or a sunscreening moiety [or derivative] and m is an integer from 0 to 6, in the presence of at least one chemical sunscreen ingredient, resulting in the entrapment of the sunscreen ingredients within the formed sol - gel matrix of said sol-gel materials. 10. A method according to claim 9 wherein the sunscreen ingredients are added after hydrolysis of the monomer, followed by a pH change and gelation. 11. A method according to claim 9 wherein the sunscreen ingredients are added to the polymerizing mixture prior to hydrolysis of the monomer. 12. A method according to claim 9 wherein the polymerization is performed also in the presence of a non - sunscreen functional co-dopant. 13. A method according to claim 9 wherein the polymerization is carried out under acidic, neutral or basic conditions for forming a porous gel, xerogel (dry gel) or colloidal suspension. 14. A method according to claim 9 wherein the metallic or semi metallic element is selected from silicon, titanium, zinc, aluminum, zirconium and the hydrolyzable substituent is selected from alkoxides, aryloxides, carboxylic esters, acyloxy groups, diketonato groups, hydrolizable aza groups and chlorine and the non polymerizable substituent is for coloring, leaching control, transparency/opacity control, acidity/basicity control or hydrophobicity/ hydrophilicity control or is a sunscreen moiety [or derivative]. 15. A method according to claim 9 wherein the sunscreen ingredients are chemical sunscreens. 16. A method according to claim 15 wherein the chemical sunscreens are selected from para amino benzoates, salicylates, cinnamates, benzophenones, anthranilates, dibenzoylmethanes, camphores and miscellaneous chemicals . 17. A method according to claim 12 wherein the non - sunscreen co-dopants are cosmetic ingredients or for coloring, leaching control, transparency/opacity control, acidity/basicity control, hydrophobicity/ hydrophilicity control. 18. A method according to claim 17 wherein the cosmetic ingredients are perfumes. 19. A method according to claim 9 wherein the sol - gel is obtained as a fine dispersion or as a powder by grinding or by stopping the sol from gelation by dilution or by pH changes or by adding surfactants or by using spraying techniques or by using controlled growth. 20. A method according to claim 9 wherein the sunscreen materials are at concentrations suitable for SPF values between 2 and 50. 21. A method for the protection of body tissues and other surfaces from UV radiation comprising coating said body tissues or surfaces with the sol - gel matrix of said sol-gel materials entrapping sunscreen ingredients according to claim 1. 22. Cosmetic, pharmaceutical or industrial mixtures and compositions containing at least one type of doped particle according to claim 1 which is incorporated into a cosmetic or other vehicle to be applied topically to body tissues or to other surfaces.
