Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K9/00—Medicinal preparations characterised by special physical form
  • A61K9/14—Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles
  • A61K9/141—Intimate drug-carrier mixtures characterised by the carrier, e.g. ordered mixtures, adsorbates, solid solutions, eutectica, co-dried, co-solubilised, co-kneaded, co-milled, co-ground products, co-precipitates, co-evaporates, co-extrudates, co-melts; Drug nanoparticles with adsorbed surface modifiers
  • A61K9/143—Intimate drug-carrier mixtures characterised by the carrier, e.g. ordered mixtures, adsorbates, solid solutions, eutectica, co-dried, co-solubilised, co-kneaded, co-milled, co-ground products, co-precipitates, co-evaporates, co-extrudates, co-melts; Drug nanoparticles with adsorbed surface modifiers with inorganic compounds
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23P—SHAPING OR WORKING OF FOODSTUFFS, NOT FULLY COVERED BY A SINGLE OTHER SUBCLASS
  • A23P10/00—Shaping or working of foodstuffs characterised by the products
  • A23P10/30—Encapsulation of particles, e.g. foodstuff additives
  • A23P10/35—Encapsulation of particles, e.g. foodstuff additives with oils, lipids, monoglycerides or diglycerides
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23P—SHAPING OR WORKING OF FOODSTUFFS, NOT FULLY COVERED BY A SINGLE OTHER SUBCLASS
  • A23P20/00—Coating of foodstuffs; Coatings therefor; Making laminated, multi-layered, stuffed or hollow foodstuffs
  • A23P20/19—Coating with non-edible coatings
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/0241—Containing particulates characterized by their shape and/or structure
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/0241—Containing particulates characterized by their shape and/or structure
  • A61K8/025—Explicitly spheroidal or spherical shape
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/11—Encapsulated compositions
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
  • A61K8/25—Silicon; Compounds thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/31—Hydrocarbons
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
  • A61K8/36—Carboxylic acids; Salts or anhydrides thereof
  • A61K8/361—Carboxylic acids having more than seven carbon atoms in an unbroken chain; Salts or anhydrides thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
  • A61K8/37—Esters of carboxylic acids
  • A61K8/375—Esters of carboxylic acids the alcohol moiety containing more than one hydroxy group
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/92—Oils, fats or waxes; Derivatives thereof, e.g. hydrogenation products thereof
  • A61K8/922—Oils, fats or waxes; Derivatives thereof, e.g. hydrogenation products thereof of vegetable origin
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K9/00—Medicinal preparations characterised by special physical form
  • A61K9/0002—Galenical forms characterised by the drug release technique; Application systems commanded by energy
  • A61K9/0004—Osmotic delivery systems; Sustained release driven by osmosis, thermal energy or gas
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K9/00—Medicinal preparations characterised by special physical form
  • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
  • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
  • A61K9/5005—Wall or coating material
  • A61K9/501—Inorganic compounds
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q15/00—Anti-perspirants or body deodorants
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q19/00—Preparations for care of the skin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
  • B01J13/02—Making microcapsules or microballoons
  • B01J13/06—Making microcapsules or microballoons by phase separation
  • B01J13/14—Polymerisation; cross-linking
  • B01J13/18—In situ polymerisation with all reactants being present in the same phase
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
  • B01J13/02—Making microcapsules or microballoons
  • B01J13/20—After-treatment of capsule walls, e.g. hardening
  • B01J13/22—Coating
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
  • C09B67/00—Influencing the physical, e.g. the dyeing or printing properties of dyestuffs without chemical reactions, e.g. by treating with solvents grinding or grinding assistants, coating of pigments or dyes; Process features in the making of dyestuff preparations; Dyestuff preparations of a special physical nature, e.g. tablets, films
  • C09B67/0097—Dye preparations of special physical nature; Tablets, films, extrusion, microcapsules, sheets, pads, bags with dyes
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23V—INDEXING SCHEME RELATING TO FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES AND LACTIC OR PROPIONIC ACID BACTERIA USED IN FOODSTUFFS OR FOOD PREPARATION
  • A23V2002/00—Food compositions, function of food ingredients or processes for food or foodstuffs
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K2800/00—Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
  • A61K2800/40—Chemical, physico-chemical or functional or structural properties of particular ingredients
  • A61K2800/41—Particular ingredients further characterized by their size
  • A61K2800/412—Microsized, i.e. having sizes between 0.1 and 100 microns
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K2800/00—Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
  • A61K2800/40—Chemical, physico-chemical or functional or structural properties of particular ingredients
  • A61K2800/56—Compounds, absorbed onto or entrapped into a solid carrier, e.g. encapsulated perfumes, inclusion compounds, sustained release forms

Definitions

• the present invention relates to a material consisting of a silica shell containing a fatty phase in which are dispersed silica capsules containing an aqueous phase, its preparation process, its use for the thermostimulated delivery of active substances, and compositions containing such a material.
• microencapsulation may be useful to encapsulate molecules of interest such as drugs, dyes, pigments, reagents, perfumes, pesticides, etc., to protect them from external aggression, including oxidation, for transport to a place of administration where they can be delivered or even to store them before use in conditions where they will be released from their capsule under the influence of an external stimulus.
• molecules of interest such as drugs, dyes, pigments, reagents, perfumes, pesticides, etc.
• One of the first applications of microencapsulation was the development of a carbonless copy paper marketed in the late 1960s in which microcapsules trapped ink were present on the back of a sheet of paper so as to release ink by breaking the capsules under the pressure exerted by the tip of a pen during writing.
• encapsulation is developing in various industrial sectors such as the pharmaceutical, cosmetic, food, textile and agricultural industries. Capsules and microcapsules become more and more sophisticated, especially in the pharmaceutical field where they make it possible to deliver controlled and / or
• capsules and microcapsules Different types and morphologies of capsules and microcapsules have already been proposed such as, for example, protein capsules, cyclodextrins, liposomes, concentrated lamellar vesicles, double emulsions, colloidosomes, silica-shell microcapsules, silica nanocapsules and thermosensitive polymers such as poly (N-isopropylacrylamide ( ⁇ ), thermosensitive hydrogel microspheres, microspheres of ⁇ -Polylactide, etc. ....
• thermosensitive polymers such as poly (N-isopropylacrylamide ( ⁇ ), thermosensitive hydrogel microspheres, microspheres of ⁇ -Polylactide, etc. ....
• the encapsulated phase of these materials contains several substances of different chemical nature, they are in contact with each other which does not allow, within the same material, to encapsulate substances that may have an incompatibility chemical and / or physical.
• these materials do not make it possible to contain both hydrophilic and lipophilic substances both in solubilized form since only the lipophilic substances can be present in solubilized form in the fatty phase encapsulated by the silica envelope while the hydrophilic substances are in dispersed form.
• At least two substances of interest may also possibly be incompatible with each other, said substances being lipophilic or hydrophilic and authorizing a rapid and complete release of these substances of interest under the effect of an external stimulus under mild conditions.
• the aim of the present invention is therefore to propose a material making it possible to encapsulate several molecules of interest in a compartmentalized manner and which also allow their rapid and total release under the influence of an external stimulus, and in particular an increase in temperature.
• the subject of the present invention is a material in the form of solid particles having a diameter ranging from 1 ⁇ to 1 cm and consisting of a continuous envelope E Ext comprising at least one silicon oxide, said envelope E entrapping at least one fatty phase, said material being characterized in that said fatty phase is solid at the storage temperature of said material and comprises from 50 to 99.9% by weight relative to the mass of said fat phase of a crystallizable oil having a melting point (T F ) less than 100 ° C, and in that said fatty phase contains at least one substance of lipophilic interest S L and at least one inclusion comprising a continuous envelope E Int comprising at least one silicon oxide, said envelope E Int imprisoning an aqueous phase comprising at least one substance of hydrophilic interest S H.
• T F melting point
• the term "storage temperature of said material” the temperature at which the material according to the present invention is stored before use. This temperature is always lower than the melting point of the crystallizable oil contained in the fatty phase. Generally the storage temperature corresponds to a temperature less than or equal to the ambient temperature (approximately 20 ° C.).
• the material according to the present invention has the following feature: when the material is subjected to a temperature higher than the melting temperature of the crystallizable oil, a thermal expansion of the fatty phase is observed, causing the rupture of the envelope of silica E E Ext as well as the rupture of the shell or envelopes E Int , and the rapid and complete release of the molten fatty phase (that is to say in the liquid state) comprising the substance or substances of interest S L , as well as the release of the aqueous phase contained in the inclusions and comprising the substance or substances S H.
• the silicon oxide forming part of the envelope is known to be a thermal insulator.
• the thermal expansion of the fatty phase allows to cause both the rupture of the envelope E Ext and that of the envelope or envelopes E Int .
• crystallizable oil means fats and fat mixtures, of natural origin (animal or vegetable) or synthetic, with a melting point greater than 15 ° C, preferably, the melting point of which varies from about 20 to 100 ° C., and in particular from 20 to 50 ° C. All the melting points mentioned in the description of the present application refers to melting points determined by differential scanning calorimetry at atmospheric pressure or "Differential Scanning Calorimetry" (DSC) in English.
• DSC Different Scanning Calorimetry
• the crystallizable oil forms a majority part of the fatty phase and may even, in addition to the substance or substances of interest S L and the inclusions, be the sole constituent thereof.
• the crystallizable oil preferably represents from 75 to 99.9% by weight approximately based on the weight of the fatty phase.
• crystallizable oil naturally depends on the application envisaged for the material and therefore on the temperature at which it is desired to observe the thermal expansion of the fatty phase and consequently the rupture of the silica envelopes E Ext and E Int .
• paraffins such as paraffins having a melting point between 42 and 44 ° C. or between 46 and 48 ° C. [RN-8002-74-2] sold by the Company. Merck company,; triglycerides; fatty acids; rosin; waxes (long alkanes) such as eicosane and octadecane; hydrogenated vegetable oils and mixtures thereof; and synthetic bitumens.
• paraffins such as paraffins having a melting point between 42 and 44 ° C. or between 46 and 48 ° C. [RN-8002-74-2] sold by the Company. Merck company,; triglycerides; fatty acids; rosin; waxes (long alkanes) such as eicosane and octade
• the material according to the present invention is preferably in the form of a powder of spherical or substantially spherical particles.
• the particle diameter preferably varies from 5 ⁇ to about 500 ⁇ , and even more preferably from 10 to 200 ⁇ .
• the silica envelope E Ext must have a thickness sufficient to have a mechanical strength allowing the encapsulation of the fatty phase. However, the silica shells E Ext and E Int must also have a thickness that allows them to break upon raising the temperature to a temperature greater than the melting temperature of the fatty phase.
• the thickness of the silica envelope E Ext generally varies from 0.1 to 2 ⁇ approximately, and preferably from 0.2 to 2 ⁇ approximately.
• the thickness of the silica envelope or envelopes E Int generally varies from 0.1 to 1 ⁇ approximately, and preferably from 0.2 to 0.8 ⁇ approximately.
• the envelopes E Ext and / or E Int may further comprise one or more metal oxides of formula MeO 2 in which Me is a metal chosen from Zr, Ti, Th, Nb, Ta, V , W and Al.
• the envelopes E Ext and E Int consist of a mixed matrix of SiO 2 -MeO 2 type in which the content of MeO 2 remains minor in relation to the oxide content of silicon, preferentially the MeO 2 content represents from 1% to 40% by weight, more particularly from 5% to 30% by weight relative to the total weight of the shell.
• the medicaments active principles
• the active ingredients that can be used in cosmetics
• the chemical reagents dyes, pigments, inks, etc ...
• these substances are incorporated in the fatty phase when they are lipophilic and in the aqueous phase of the inclusion or inclusions when they are hydrophilic, the a person skilled in the art who knows how to discriminate the lipophilic or hydrophilic nature of a given substance as a function of its HLB value ("Hydrophilic-Lipophilic Balance": hydrophilic / hydrophobic balance).
• bactericides such as antiseptics and antibiotics, anti-inflammatories, analgesics, local laxatives, hormones, proteins, etc.
• cosmetic active principles include vitamins, sunscreens, antioxidants such as antiradicals such as superoxide dismutase, perfumes, odor absorbing agents, deodorants, antiperspirants , dyes, pigments, emollients, moisturizers, etc.
• color reagents examples include pH indicators, catalysts, polymerization initiators, monomers, complexing agents, etc.
• the substance or substances of interest S L generally represent from 0.001 to 50% by weight approximately, and preferably from 0.01 to 25% by weight approximately of the total mass of the fatty phase.
• the substance or substances of interest S H generally represent from 0.001 to 50% by weight approximately, and preferably from 0.01 to 25% by weight approximately of the total mass of the aqueous phase contained in the inclusion or inclusions present within the fatty phase.
• the fatty phase and / or the aqueous phase of the inclusion or inclusions may also contain one or more additives conventionally used in emulsions and among which may be mentioned by way of example the protectors or of conservation of the substance of interest, such as antioxidants, anti-UV agents, etc.
• the invention also relates to a process for preparing the material as defined above. This method is characterized in that it comprises the following steps:
• a fatty phase comprising from 50 to 99.9% by weight relative to the mass of said fat phase of a solid crystallizable oil (HC) having a melting temperature T F less than 100 ° C at a temperature T H c such that T H c is greater than T F , to obtain a crystallizable oil in the liquid state;
• HC solid crystallizable oil
• a fourth step subjecting the liquid mixture resulting from the third step to mechanical stirring to obtain a water-in-oil emulsion (W / H) formed of droplets of aqueous phase dispersed in the continuous fat phase at the liquid state and in which the colloidal solid particles P1 are present at the interface formed between the continuous fat phase and the dispersed aqueous phase droplets PA1;
• a sixth step subjecting the liquid mixture resulting from the fifth step to mechanical stirring to obtain a double water-in-oil-in-water emulsion (W / O / E) formed of a continuous aqueous phase ( PA2) containing droplets of fatty phase in the liquid state, each of said droplets of fatty phase in the liquid state containing at least one droplet of aqueous PA1 phase; double emulsion in which the solid particles P2 colloidal are present at the interface formed between the continuous aqueous phase PA2 and dispersed liquid phase droplets in the liquid state;
• the colloidal solid particles PI added in the fatty phase during the second step and the particles P2 present in the aqueous phase PA2 during the fifth step may be inorganic or organic.
• it is inorganic particles selected from the group of oxides, hydroxides and sulfates of metals.
• oxides mention may be made especially of oxides of silicon, titanium, zirconium and iron, as well as their salts such as silicates (for example clays).
• the colloidal carbon particles there may be mentioned in particular polymeric particles, for example latex particles.
• the solid particles PI and P2 generally have a size of less than a few micrometers.
• the particles generally have an average size of between 5 and 5000 nm, and preferably between 5 and 500 nm.
• the colloidal solid particles PI and P2 are of identical chemical nature and are chosen from silicon oxide nanoparticles.
• silicon oxide nanoparticles For example, we can mention in particular the products sold under the trade name Aerosil® by the company Evonik Degussa.
• the particles PI and P2 may be of identical or different diameter.
• particles of silicon oxide having a mean diameter of about 12 nm may be used as particles P1
• particles of silicon oxide having a mean diameter of about 16 nm may be used as particles P2. .
• the amount of colloidal solid particles P1 generally ranges from 0.01% to 10%, in particular from 0.1% to 7% by weight relative to the total mass of the aqueous phase PAL.
• the amount of colloidal solid particles P1 present in the fatty phase varies as a function of the average volume size of the aqueous phase droplets PA1 desired in the emulsion and whose average diameter varies from 0.1 ⁇ to 100 ⁇ , from preferably from 1 to 50 ⁇ , and even more preferably from 5 to 20 ⁇ approximately.
• the amount of colloidal solid particles P2 generally ranges from 0.01% to 5%, in particular from 0.5% to 2% by weight relative to the total weight of the W / O emulsion.
• the quantity of colloidal solid particles P2 present in the aqueous phase PA2 varies as a function of the average volume size of the dispersed fatty phase droplets desired in the emulsion and whose mean diameter varies from 15 to 100 ⁇ , preferably from 30 to 80 ⁇ , and even more preferably from 40 to 70 ⁇ approximately.
• the colloidal solid particles generally have a hydrophilic and charged surface, which does not favor their adsorption on the surface of the droplets of the dispersed PA1 aqueous phase or on the surface of the droplets of the fatty phase dispersed in the aqueous phase PA2.
• the colloidal solid particles PI and P2 are functionalized on the surface to promote their adsorption at the interface formed between the continuous fat phase and the aqueous phase PA1 during step 4 ) or between the aqueous phase PA2 and the droplets of fat phase dispersed during step 6).
• the colloidal solid particles P1 and P2 can thus be functionalized with compounds bound to their surface by covalent bonds. This can be achieved by prior treatment of the particles, in particular by chemical grafting of a compound comprising hydrophobic groups such as a trialkoxysilane of the formula -Si- (O ') 3, wherein R is a linear or branched Ci to C 12, particularly C 2 to Qo, especially n-octyl, optionally bearing an amino group and R', identical or different from R 1 is a linear or branched C 1 -C 12 , in particular C 1 -C 6 , alkyl group, and most particularly ethyl.
• a compound comprising hydrophobic groups such as a trialkoxysilane of the formula -Si- (O ') 3, wherein R is a linear or branched Ci to C 12, particularly C 2 to Qo, especially n-octyl, optionally bearing an amino group and R', identical or different from R 1 is a linear or
• the colloidal solid particles PI and P2 may also be functionalized by adsorption of surfactant molecules on their surface which make it possible to confer some hydrophobicity, the hydrophilic end of the surfactant being adsorbed on the surface of the particles.
• the surfactants that can be used to functionalize the particles P1 and P2 are preferably cationic or anionic surfactants.
• sodium alkyl sulphates such as, in particular, sodium dodecyl sulphate (SDS) and alkyltrimethylammonium bromides.
• the surfactant is preferably selected from surfactants with a charge opposite to that of the surface of the colloidal solid particles P1 and P2. This choice makes it possible to promote the adsorption of the surfactant on the surface of the particles.
• silica nanoparticles whose surface is functionalized with a quaternary ammonium such as those sold under the name Aerosil® A380 by the company Evonik Degussa, with a diameter of 7 nm, and whose surface is functionalized by cetyltrimethylammonium bromide (CTAB), silica nanoparticles 12 nm in diameter, sold under the name Aerosil® AR 816 and 16 nm diameter silica nanoparticles, sold under the name Aerosil® AR 972 by the company Evonik Degussa.
• CAB cetyltrimethylammonium bromide
• Functionalization of the colloidal solid particles PI and P2 by a surfactant can also be carried out in situ, that is to say, when they are introduced into the fatty phase and respectively into the aqueous PA2 phase of the emulsion.
• the fatty phase and the aqueous phase PA2 of the emulsion further contain said surfactant in an amount preferably less than the critical micelle concentration (CMC), the latter then being adsorbed on the surface of the particles when those These are in the aqueous phase of the emulsion.
• the amount of surfactant varies from 1/200 to 1/3 of the CMC.
• the aqueous PA1 and PA2 phases mainly comprise water and optionally an alcohol, such as methanol, ethanol, isopropanol or butanol, preferably ethanol.
• the mechanical stirring carried out during the fourth and sixth steps can in particular be carried out in a device intended to emulsify such as, for example, in devices sold under the trade names Ultra-Turrax® or ayneri®.
• the size distribution of the droplets of the aqueous PA1 phase in the W / O emulsion is generally narrow (U ⁇ 40%).
• the addition of at least one precursor of silicon oxide at acidic pH causes the condensation of said precursor at the interface formed between the fat phase globules in the state solid and the aqueous PA2 phase, and the interface between the PA1 aqueous phase droplets and the fatty phase.
• the precursors of silicon oxide may be chosen from silicon alkoxides and in particular from tetramethoxyorthosilane (TMOS), tetraethoxyorthosilane (TEOS), dimethyldiethoxysilane (DMDES), (3-mercaptopropyl) trimethoxysilane and (3-aminopropyl) triethoxysilane, N- (3-trimethoxysilylpropyl) pyrrole, 3- (2,4-dinitrophenylamino) propyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, phenyltriethoxysilane, methyltriethoxysilane and mixtures thereof.
• TMOS tetramethoxyorthosilane
• TEOS tetraethoxyorthosilane
• DMDES dimethyldiethoxysilane
• the thickness of the envelope formed around each aqueous phase droplet PA1 as well as around each droplet of fatty phase depends on the amount of silicon oxide precursors used during the eighth stage and the diameter of the globules of the dispersed fatty phase and the diameter of the PA1 aqueous phase droplets dispersed in the fatty phase. This quantity is expressed relative to the total surface area in m 2 of the globules of the dispersed phase of the emulsion and of the dispersed aqueous phase droplets PA1.
• the amount of silicon oxide precursor varies from 0.005 to 4 M / m 2 , and even more preferably from 0.01 to 2.2 M per m 2 of total surface area of the globules of the dispersed phase and droplets of aqueous PA1 phase of the emulsion.
• steps 8 to 10 can be performed several times until the desired thickness is achieved.
• the silica casings of the material according to the invention comprise, in addition to the silicon oxide, a metal oxide
• the aqueous phases PA1 and PA2 are also added to the emulsion at least one precursor of a metal oxide of formula MeO 2 , said precursor being selected from alkoxides, chlorides or nitrates of metals selected from Zr, Ti, Th, Nb, Ta, V, W and Al.
• the amount of these metal oxide precursors of formula MeO 2 varies from 0.001 M to 1 M, and preferably from 0.01 to 0.6 M per m 2 of total surface area of the globules of the dispersed phase. and PA1 aqueous phase droplets of the emulsion.
• the pH of the aqueous phases PA1 and PA2 during the eighth step preferably varies from 0.01 to 4, and even more preferably from 0.1 to 2.1.
• the acid used to adjust the pH of the aqueous PA1 and PA2 phases may be chosen from inorganic and organic acids among which may be mentioned in particular hydrochloric acid, acetic acid, nitric acid and sulfuric acid.
• the material according to the invention can be separated from the aqueous phase and recovered by any conventional separation technique known to those skilled in the art, such as filtration, centrifugation and the use of sieves. It is then preferably washed, for example with water, and then dried for example by lyophilization to give a powder.
• the material thus obtained is storage stable for several months provided that the storage temperature is lower than the temperature T F of the fat phase trapped in the silica shell.
• the material according to the invention may be used in the form of a powder or dispersion in a solvent to deliver the substance (s) of lipophilic interest (s) present in the solid fatty phase trapped in the envelope based on silica, as well as the substance or substances of hydrophilic interest (s) present in the aqueous phase PA1 inclusions, said aqueous PA1 phase itself being trapped and separated from the fatty phase by a silica envelope.
• the invention therefore also relates to the use of a material according to the invention and as described above for the delivery thermostimulated and simultaneous at least one substance of lipophilic interest and at least one substance of hydrophilic interest.
• the delivery of the substances of lipophilic and hydrophilic interest is obtained by thermal expansion of the fatty phase inducing the rupture of the envelope surrounding the fatty phase, as well as the rupture of each of the silica shells surrounding each of the dispersed PA1 aqueous phase droplets. in the fatty phase, under the effect of an increase in the temperature of the material at a delivery temperature T D such that T D > T F.
• the crystallizable oil present in the fatty phase is preferably selected from crystallizable oils having a melting point of less than 37 ° C.
• the ingested composition will be at body temperature, generally 37 ° C or more, which will lead to the melting of the fatty phase and its volume expansion and thus the rupture of the silica casings and the delivery of the active ingredients or active ingredients.
• the substances of lipophilic and hydrophilic interest are cosmetic active ingredients and the material is one of the components of a cosmetic composition with topical application, such as a powder, a cream or a gel.
• a cosmetic composition with topical application such as a powder, a cream or a gel.
• the heating of the fatty phase of the material at a temperature above T F can in this case be caused by a local friction during the spreading of the cosmetic composition, which induces a local heating causing rupture of the envelopes and the release local substances of interest.
• the cosmetic composition is in the form of a powder, its application by spreading may be accompanied by a change in texture (transformation of the powder into a composition having a greasy feel due to the rupture of the envelope).
• the material according to the invention can for example be used for the manufacture of solid foams in the field of insulating materials.
• the subject of the invention is also the use of the material as described above, as an ingredient, for the preparation of pharmaceutical, cosmetic or food products, as well as pharmaceutical, cosmetic or food products, containing, as an ingredient, of ingredient, at least one material according to the invention.
• compositions may contain conventional pharmaceutical, cosmetic or food carriers well known to those skilled in the art, as well as one or more surfactants intended to promote the release of the liquid fatty phase and the encapsulated aqueous phase upon rupture of the different envelopes of silica.
• the present invention is illustrated by the following exemplary embodiments, to which it is however not limited.
• CAB Cetyl trimethylammonium bromide
• CMC critical micellar concentration
• the materials obtained were characterized using an inverted optical microscope sold under the trade name Axiovert® XI 00 by the company Zeiss and equipped with a hot plate from the Mettler company to control the temperature and the speeds of heating and cooling.
• the size distribution of the emulsions was studied using a granulometer sold under the trade name Mastersizer Hydro MS2000 by the company Malvern Instrument. Granulometric measurements were made at 25 ° C in pure water.
• the scattering intensity as a function of the angle that was collected was transformed using the Mie-Lorenz theory.
• the particle size distribution was expressed by their weighted average diameter (D) and their polydispersity (P) by applying the following equations (1) and (2)
• - D is the median diameter, that is to say the theoretical opening of the sieve such that 50% of the particles, by mass, have a larger diameter and 50% a smaller diameter.
• a material according to the invention consisting of a silica envelope containing a crystallizable oil comprising droplets of dispersed aqueous phase, each of said droplets being itself surrounded by a silica envelope.
• oily and aqueous phases do not contain substances of interest, this example being given to demonstrate the structural feasibility of the compartmentalized material according to the process according to the invention.
• Rhodamine B used hereinafter in the aqueous phase in order to demonstrate the formation of the aqueous phase droplets surrounded by a silica envelope within the oily phase may moreover be considered as a substance of hydrophilic interest.
• the amount of CTAB was adapted to the mass of the silica particles in order to obtain a specific coverage of 12 nm 2 / CTAB molecule at the silica / water interface, considering that all the CTAB used is adsorbed on the surface of the particles. of silica.
• aqueous PA1 phase 20% by weight of an aqueous PA1 phase containing 0.02% by weight of Rhodamine B and 0.1 M of NaCl preheated at a temperature of 45 ° C. in the fatty phase (Eicosane) also previously heated to 45 ° C and containing a dispersion of silica particles AR 972.
• the amount of silica particles AR 972 to be dispersed in the fatty phase is calculated as a function of the amount of aqueous phase, at a rate of 50 mg of silica particles per gram of aqueous phase.
• aqueous PA2 phase 20% by weight of the W / O emulsion obtained above in the preceding step was then added to an aqueous PA2 phase containing 0.1 M NaCl and the functionalized AR 816 silica particles as prepared above .
• the amount of functionalized particles depends on the total mass of the W / O emulsion used.
• the aqueous PA2 phase contained 8 mg of functionalized particles per gram of W / O emulsion introduced into the aqueous PA2 phase.
• the emulsification of the W / O emulsion in the aqueous PA2 phase was carried out using the same stirrer as above in step ii) ending with stirring at 8000 rpm. for 2 minutes.
• the double W / O / W emulsion thus obtained was then stored in a thermostatic bath at 45 ° C. without stirring for a few minutes to allow the limited coalescence phenomenon to occur (adsorption of the silica particles on the surface of the phase droplets. scattered fat).
• the emulsion was then removed from the thermostated bath and then allowed to return to ambient temperature in order to cause solidification of the fatty phase.
• the double W / O / W emulsion obtained above in the previous step was diluted to 7% by weight by addition of an aqueous solution containing 0.5% by weight of CTAB, 46% by mass of 37% by volume hydrochloric acid (HC1) and 0.1 M NaCl under cold conditions, that is to say at a temperature of 4 ° C.
• the pH of the mixture thus formed was close to 0, which then makes it possible to carry out the hydrolysis and the condensation of the TEOS at the oil / water interfaces.
• the mineralization of the emulsion was thus carried out by introducing 10 ml of the acidified double emulsion into test tubes and then adding 0.3 g of TEOS per tube.
• the tubes were subjected to continuous agitation on a rotating wheel at 9 rpm in a thermostatically controlled chamber at 25 ° C. After one hour, the expected material was recovered by centrifugation and washed several times with water containing 0.1 M NaCl.
• FIG. 1 shows a photograph in optical microscopy of the various emulsions prepared during the preparation of the material according to the invention: FIG. 1a) W / O emulsion, FIG. 1b): double emulsion E / H / E at room temperature before the mineralization step, Figure 1a) dual W / O / W emulsion at room temperature after the mineralization step; Figure 1d): curve showing the particle size distribution of the final material (percentage by volume (%) as a function of the particle diameter (mm)).
• FIG. 2 is an image taken in epifluorescence confocal microscopy of the material at ambient temperature, that is to say at a temperature at which the fatty phase is in the solid state, and at two different magnifications.
• the white arrow designates the water / oil interface of the inclusions of aqueous phase droplets PA1 each encapsulated by a silica envelope. It is clear, thanks to Rhodamine B added in the aqueous phase PA1, the structure of the material according to the invention.
• Rhodamine B is exclusively present in the water droplets encapsulated by a silica envelope, the concentration of rhodamine being moreover higher as the water / oil interface is approached, the said droplets being encapsulated water being dispersed in the fatty phase itself encapsulated by a silica shell.
• FIG. 3 In this figure, the discontinuous thick white lines indicate the presence of the fluorescence-free fatty phase, the discontinuous fine white lines indicate the footprint of the water droplets, which are now free of fluorescence, and the white arrow indicates the presence some mineralized water droplets outside the outer shell after it breaks.
• FIGS. 3a and 3c also show a few droplets in fluorescence corresponding in fact to the imprints left by the water droplets which were initially encapsulated in the internal silica casings and which have spread after rupture of these internal silica shells. .
• PAl dispersed in the fatty phase and that the thermal expansion of the fatty phase by raising its temperature causes both the rupture of the outer envelope of silica surrounding the fat phase globules and the rupture of internal silica envelopes surrounding the droplets of aqueous PAl phase dispersed in the fatty phase.

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