WO2004105933A2 - Calcium phosphate capsules, method for the production thereof, and uses of the same - Google Patents

Calcium phosphate capsules, method for the production thereof, and uses of the same Download PDF

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Publication number
WO2004105933A2
WO2004105933A2 PCT/FR2004/001222 FR2004001222W WO2004105933A2 WO 2004105933 A2 WO2004105933 A2 WO 2004105933A2 FR 2004001222 W FR2004001222 W FR 2004001222W WO 2004105933 A2 WO2004105933 A2 WO 2004105933A2
Authority
WO
WIPO (PCT)
Prior art keywords
characterized
surfactant
calcium phosphate
eo
po
Prior art date
Application number
PCT/FR2004/001222
Other languages
French (fr)
Other versions
WO2004105933A3 (en
Inventor
Dominique Dupuis
Franck Aurissergues
Original Assignee
Rhodia Chimie
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to FR03/06148 priority Critical
Priority to FR0306148A priority patent/FR2855074A1/en
Application filed by Rhodia Chimie filed Critical Rhodia Chimie
Publication of WO2004105933A2 publication Critical patent/WO2004105933A2/en
Publication of WO2004105933A3 publication Critical patent/WO2004105933A3/en

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J13/00Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
    • B01J13/02Making microcapsules or microballoons
    • B01J13/04Making microcapsules or microballoons by physical processes, e.g. drying, spraying
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J13/00Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
    • B01J13/02Making microcapsules or microballoons

Abstract

The invention relates to capsules having an organic core and a mineral hull, and is characterised in that said core partially or entirely consists of at least one active ingredient, said mineral hull partially or entirely consists of calcium phosphate, and the capsule itself contains at least one surfactant and/or at least one amphiphilic polymer. The invention also relates to a method for producing said capsules, and to the uses of the same.

Description

CAPSULES CALCIUM PHOSPHATE, METHOD OF PREPARATION andits

USES

The present invention relates to calcium phosphate capsules, as well as its process of preparation and their uses. The encapsulation systems are widely used by the industry for the formulation of chemical compounds.

Various encapsulation techniques are already available for packaging various active ingredients also called active ingredients. This type of packaging is particularly preferred when it is desired to mask the taste of an active ingredient, to control its release in time and / or to protect it from its environment. Overall, there are two types of encapsulation techniques. The first type leads to said reservoir system. The active material is immobilized in the center of a capsule with a polymeric nature membrane. This type of capsule is generally obtained by the so-called interfacial polycondensation technique. It consists in causing the synthesis of a polymer at the interface of two immiscible liquids. This produces microspheres of 10 to 30 microns in average diameter consisting of a liquid core surrounded by a polymer shell representing only 5 to 15% of the total weight of the capsule. The polymeric membrane provides vis-à-vis protection of the external medium of the liquid core that typically contains an active material and its porosity allows to control the diffusion out of the capsule. This type of encapsulation is particularly proposed for the packaging of pesticide type of active ingredients of which is to control the release over time. also lead to this system said reservoir, said spray coating techniques, by phase separation coating and coating by solidification.

The second type of encapsulation technique leads to a matrix system itself. The active material to be encapsulated is dispersed in a network is organic polymer or inorganic type such as silica. As representative examples of such encapsulation, mention may more particularly be mentioned the technique of mineral encapsulation by sol-gel route. Technical conventional sol-gel is to initiate the hydrolysis and polycondensation of a metal alkoxide in an aqueous or hydroalcoholic medium and comprising the active material. to be packaged. This results in the formation of a gel, wherein said dispersed active material is located, which leads after drying to a porous glass. According to a variant of the sol-gel technique, said emulsion forming an inorganic oxide network, typically silica, from a molecular precursor of the alkoxide in the presence of a water in oil emulsion in which dispersed the active ingredient. The active material present during the hydrolysis step and condensation of the inorganic material is then trapped in the powder. But according to the intended application area or as the active ingredient to be encapsulated, the implementation of these techniques is not always feasible.

Indeed in the case of encapsulation of food ingredients, it is necessary to use materials compatible with the food industry. To meet the requirements of manufacturers, it became necessary to find usable capsules and encapsulation methods in food industry.

So the problem is to solve the invention to provide new capsules using materials compatible with the food industry and propose a process for preparing these capsules easy to implement.

For this purpose the invention provides capsules comprising an organic heart and a mineral cortex characterized in that the heart is in whole or part of at least one active principle and in that the mineral cortex consists wholly or partly calcium phosphate and in that said capsule comprises at least one surfactant and / or at least one amphiphilic polymer.

The invention also provides a process for preparing capsules mentioned above characterized in that it comprises: precipitation in an aqueous calcium phosphate media in the presence of the active ingredient and in the presence of at least one surfactant and / or least one amphiphilic polymer; separation of the formed capsules to the dispersion obtained above; and optionally the formulation in dry form. The invention also relates to the use of such capsules in the food, cosmetic, plant health, therapeutic, aromatic polymers such as textiles polymers.

The capsules according to the invention have the advantage of having a mineral cortex consists wholly or partly of calcium phosphate, said calcium phosphate being compatible with the food industry. The capsules still have the advantage of allowing a controlled release of the encapsulated active ingredient. In particular the active ingredients they contain may be generally released by splitting of the capsule or by induced degradation thereof, particularly by a pH change;

The inorganic nature of the bark of the capsules according to the invention constitutes an effective protective barrier of the active ingredient vis-à-vis the surrounding environment while allowing the appropriate exchanges therewith.

Advantageously, the capsules according to the invention exhibit thermal stability up to 350 ° C. Indeed it is possible to thermally protect an active ingredient. For example an active ingredient which usually degrades at 100 ° C can be protected by the capsule and remains sufficiently stable when the capsule containing the active prinipe is heated to a temperature up to 200 ° C.

Finally, this capsule is prepared in the context of the present invention in sufficiently mild operating conditions do not affect the integrity of said active ingredients. By the term "sufficiently mild operating conditions" is understood within the meaning of the present invention are temperatures not exceeding 100 ° C, and pH greater than 5 and less than 9, without use of organic forerunners. Thanks to these mild conditions, the active ingredient to immobilize is indeed not exposed during its conditioning temperature values ​​and if necessary pH may harm him.

Other advantages and features of the invention will become apparent from reading the description and examples given purely illustrative and not exhaustive, that follow. The invention firstly relates to capsules comprising an organic heart and a mineral cortex characterized in that the heart is in whole or part of at least one active principle and in that the mineral cortex consists wholly or calcium phosphate portion and that said capsule comprises at least one surfactant and / or at least one amphiphilic polymer. The capsules according to the invention can advantageously have a spherical morphology.

The size of the capsules according to the invention is representative of the size of the emulsion, in particular determined by scanning electron microscopy, when emulsion occurs during the manufacturing process. The capsules according to the invention may also be in the form of powder, more or less agglomerated, freeze-dried or not.

The first essential component of the capsules according to the invention is constituted by an organic heart.

By organic heart, means any organic substances which may be encapsulated and incorporated all or part of at least one active principle.

The organic substances can be encapsulated may in particular be made of an insoluble organic compound in water. As insoluble organic compound in suitable water, there may be mentioned organic solvents, organic oils of animal or plant origin, or inorganic, as well as waxes derived from the same origin, or mixtures thereof.

As organic solvents there may be mentioned among other petroleum fractions, naphthenic oils, paraffin (vaseline or cutting paraffinic Isopar M Exxon), petroleum ether, the linéraies or branched alkanes such as pentane, hexane and their mixtures thereof, aromatic hydrocarbons such as benzene, toluene, xylene and anisole, ethers such as tetrahydrofuran, diethyl ether, dimethyl ether and tert-butyl, chlorinated solvents such as dichloromethane, chlorobenzene, dichlorobenzene, chloroform or benzotrifluoride, and mixtures thereof. As organic oils of animal origin, include among others, sperm whale oil, whale oil, seal oil, sardine oil, herring oil, shark oil, Cod liver oil ; pork fat, sheep fat (tallow). As waxes of animal origin include beeswax. As examples of organic oils of vegetable origin may be mentioned, among others, rapeseed oil, sunflower oil, peanut oil, olive oil, nuts, corn oil, soybean oil, linseed oil, hemp oil, grape seed oil, coconut oil, palm oil, cotton seed, babassu oil, jojoba oil, sesame oil, castor oil, cocoa butter, shea butter. As vegetable waxes, carnauba wax include.

As regards the mineral oils there may be mentioned among other petroleum fractions, naphthenic oils, paraffin (vaseline or cutting paraffinic Isopar M Exxon).

Paraffin waxes may also be suitable for preparing the emulsion. The products obtained from the alcoholysis of the abovementioned oils can also be used as well as essential oils and silicone oils.

Fatty acid, saturated or unsaturated fatty alcohol, saturated or unsaturated fatty acid ester, or mixtures thereof are also useful. More particularly, said acids comprise 8 to 40 carbon atoms, more particularly 10 to 40 carbon atoms, preferably 18 to 40 carbon atoms, and may comprise one or more ethylenic unsaturations, conjugated or not, and optionally one or more groups hydroxyls. As for alcohol, they may include one or more hydroxyl groups. Examples of saturated fatty acids include palmitic, stearic and behenic acid. Examples of unsaturated fatty acids include myristoleic, palmitoleic, oleic, erucic, linoleic, linolenic, arachidonic and ricinoleic acids and their mixtures surfactants and non-solvents. As for the alcohols thereof include in particular 8 to 40 carbon atoms, preferably 10 to 40 carbon atoms, optionally one or more ethylenic unsaturations, conjugated or not, and possibly more hydroxyl groups. Polymers comprising several hydroxyl groups may also be suitable, such as polypropylene. Examples of alcohols that may be mentioned for example those corresponding to the abovementioned acids. Regarding the fatty acid esters, these may advantageously be obtained from fatty acids, chosen from the compounds named above. The alcohols from which these esters are prepared include more particularly 1 to 6 carbon atoms. Preferably it is methyl, ethyl, propyl, isopropyl. Furthermore, it is not excluded to use as the organic substance of mono-, di- and tri- glycerides.

The organic substance may be encapsulated preferred according to the invention is soybean oil.

By way of active principle, can be used according to the invention a compound or mixture of compounds of interest food, cosmetic, plant health, therapeutic, aromatic, or used in the polymer field, such as textiles polymers. There may be mentioned vitamins, food additives such polysaccharides, flavors such as vanillin, dyes, baking powders, anti-UV agents, fragrances such as menthol, anti-mite agents such as benzyl benzoate, insecticides, or fungicides.

The second essential constituent of capsules according to the invention is constituted by the inorganic shell calcium phosphate.

Calcium phosphate is also understood calcium pyrophosphate of the invention. The inorganic shell of the capsules according to the invention is preferably constituted by a compound having a structure apatitic calcium phosphate shown by an X-ray analysis of these particular apatitic compounds include for example compounds like hydroxyapatite calcium phosphate, calcium phosphate or calcium phosphate monétite br