WO1995011012A1

WO1995011012A1 - Water-resistant cosmetics

Info

Publication number: WO1995011012A1
Application number: PCT/EP1994/003459
Authority: WO
Inventors: Claudia Hohmann; Detlef Koch; Werner Pflug
Original assignee: Rotring International Gmbh & Co Kg
Priority date: 1993-10-21
Filing date: 1994-10-21
Publication date: 1995-04-27
Also published as: DE4336407A1

Abstract

Cosmetic compositions and dispersions containing the same comprise (a) a solid particulate, water-insoluble matrix made of at least one water-insoluble, non-polymer, matrix-forming material solid at room temperature and (b) a water-insoluble, cosmetically active ingredient enveloped by the matrix. The matrix particles have an average size of about 1 νm or less. Also disclosed is a process for preparing such cosmetic compositions and dispersions and their use.

Description

Waterproof cosmetics

The invention relates to a cosmetic composition, an aqueous dispersion containing this composition, a process for its production and its use as / in cosmetic product (s) or for the production of cosmetic products.

Conventional methods for making small, discrete, core-containing particles of hydrophobic polymer material include the step of polymerizing the monomer so as to form a core encapsulating polymer shell.

For example, Sole nee Haina in US Pat. No. 4,421,660 describes how particles of inorganic solid such as TiO ₂ having a colloidal size are encapsulated in a hydrophobic addition polymer such as polystyrene in a polymerization process, a water-insoluble hydrophobic monomer being contained in an aqueous, colloidal Dispersion of the inorganic particles is dispersed and then this mixture is subjected to an emulsion polymerization. Another polymerization process is described by Bayle in US-A-4,264,700. According to this patent, magnetic toner particles are produced by a vinyl monomer Polymerization initiator, magnetic particles and a solvent for the monomer as droplets in the form of a discontinuous phase are suspended in a continuous, aqueous phase. Then the monomers are polymerized in the discontinuous phase after removal of the solvent to form the polymer-coated toner particles.

Another method involving polymerization is described by Nguven et al. in US-A-4,530,961. In this, soot particles are treated in water with a water-soluble peroxide and then a water-soluble acrylic monomer is added. In the subsequent homogeneous free-radical polymerization of the monomer, grafting of the monomer onto the soot particles occurs at the same time.

In all of these processes, suspension polymerization of a monomer is an essential part of the encapsulation process. However, the conditions required for the polymerization of a surrounding monomer limit, for example, the range of usable concentration ratios of the enclosed component to the component forming the shell, the physical properties of the enclosed components and the possible choice of suitable auxiliaries such as surfactants. Furthermore, the emulsion polymerization is a complex reaction and for every desired combination of materials and the resulting concentrations, research into suitable polymerization conditions is necessary.

Micale describes in US Pat. No. 4,665,107 the production of a polymer shell which lies tightly around solid particles (pigment) with a submicron size (> 1 μm) in order to form a low-viscosity writing fluid. This liquid is produced by first dispersing the pigment submicron particles in an intermediate solvent, which also contains the encapsulating, water-insoluble polymer, and then dispersing the mixture in water and dissolving the intermediate solution. it will. The polymer material is not changed significantly during the coating.

Another polymer dispersion is described by Ober et al. in US-A-4,692,188, according to which a polymer and an oil-soluble dye are dissolved in a water-immiscible organic solvent. The mixture is then combined with a solution of water and surfactant, the combination is emulsified and the organic solvent is then evaporated, so as to obtain the dye and the polymer suspended in an aqueous phase.

With the of Micale and Ober et al. described methods and in particular the use of an intermediate solvent, however, have two serious disadvantages. The first disadvantage is the economic outlay, which is necessary due to the additional step of removing the solvent and then cleaning the removed solvent for reuse or disposal. The second disadvantage is that typical intermediate solvents such as methylene chloride tend to cause environmental problems and the removal of trace amounts of the solvent from the end product is necessary in order to protect the health of end consumers.

Methods are also known for producing capsules with active components enclosed therein, in which the capsule size is in the micrometer and submicrometer range.

Mivano et al. in US-A-3 856 699 describe a process for the production of capsules with walls made of wax-like material, in which a wax-like material, which contains a core material, in a moving aqueous medium at a temperature above the melting point of the wax-like material Material is dispersed dropwise and then the wax-like material is transferred to a still aqueous medium which is at a temperature points, which is lower than the melting temperature of the wax-like material. The size of the droplets is controlled by the stirring speed and is a minimum of 20 to 500 μ.

In the field of cosmetics, compositions are known in which a more or less thick film forms on the skin after use, which protects the applied active ingredient, for example, against premature and unintentional washing off by water.

DE 37 10 292 AI and DE 37 10 293 AI use polymer cellulose derivatives in particular to produce waterproof sun protection products that form waterproof films on the skin.

EP-A-0 356 196 describes a cosmetic preparation in which a film is formed on the skin from a stable oil-in-water emulsion and comprises a thin, flexible acrylate homopolymer layer and a sunscreen.

EP-A-0 265 228 describes a skin protection agent which comprises an acrylic copolymer of ethyl acrylate and methacrylic acid.

In addition, DE 25 44 180 describes a fat-containing cosmetic preparation which contains certain UV absorbers and ointment and cream bases or solvents which are used for the production of liquid sunscreen and skin care preparations. They are produced by stirring the components together and homogenizing them at temperatures of, for example, 75 ° C.

However, the known compositions and preparations have the disadvantage that they do not penetrate into the skin, or only to a small extent or superficially, so that the water resistance described in part does not last long. The present invention is therefore based on the object of providing a cosmetic composition which is suitable as or for the production of cosmetic products, can be prepared without polymerisation processes and without the use of intermediate organic solvents which are to be removed later, after application of a permanent waterproof application of the active ingredient and can contain a variety of cosmetically active ingredients individually or in combination. If necessary, there is also a delayed delivery and thus. ^' :. Longer lasting cosmetic effect of the enclosed substance.

This object is achieved by a cosmetic composition which a) comprises a solid, particulate, water-insoluble matrix composed of at least one water-insoluble, non-polymeric, matrix-forming material which is solid at room temperature, and b) one which is enclosed in the matrix , Water-insoluble, cosmetically active ingredient, wherein the matrix particles have an average size of about 1 micron or less.

This cosmetic composition, which can also be in the form of its aqueous dispersion, can be prepared by a process which is characterized in that 1) at least one water-insoluble, non-polymeric, matrix-forming material which is solid at room temperature , and a water-insoluble active constituent to be enclosed in the matrix are heated together to a temperature sufficient to melt the matrix-forming material, 2) the hot melt formed from the matrix-forming material and active constituent is added to water with agitation, optionally with surfactant being present is to produce a stable aqueous emulsion which comprises matrix-forming material with the active ingredient enclosed therein in the form of droplets with an average size of about 1 μm or less, and 3) the stable, aqueous emulsion is cooled to room temperature to form an aqueous dispersion of solid particles of matrix-forming material with active encapsulated therein

To obtain component, which is then optionally removed from the water.

The composition or dispersion according to the invention and the method according to the invention for their production is a significant improvement over the previously known compositions or methods.

Advantageously, no polymerization is necessary in the production according to the invention to form an encapsulating matrix, since the active ingredient is not dispersed or dissolved in a monomer or a monomer mixture. In particular, there is no need to set certain emulsifying conditions which also allow polymerization of a monomer. The matrix-forming material according to the invention is not chemically changed during the production of the composition, so that the known chemical and physical properties are retained. The use of a polymeric matrix material is even eliminated altogether.

Since it is also possible to dispense with the use of an intermediate solvent for a monomer to be polymerized, costly process steps which are associated with the removal and processing of this solvent and possible environmental problems and health risks are advantageously avoided.

The rheological and physical properties of the cosmetic composition or dispersion according to the invention are determined by the mass properties, morphology and the surface properties of the matrix-forming material and are therefore independent of the nature or type of the active ingredient included. The matrix-forming material can be any material which is essentially insoluble in water, preferably less than 5%, preferably less than 3% and in particular less than 1% soluble in water, and is inert with respect to the active ingredient . It must be stable during heating, should preferably have a melting point below about 100 ° C. and form a melt which has a viscosity which is lower than about 600 mPas and preferably lower than about 500 mPas. The matrix-forming material can be a solid, a liquid or a mixture of solids and liquid, which are usually solid at room temperature.

Suitable matrix-forming materials are vegetable oils, in particular hardened palm oil, hydrogenated triglycerides of coconut and oil palm, cotton oil, castor oil and esters thereof, animal waxes such as tallow, beeswax, whale wax or aqueous lanolin, fatty acids such as stearic acid, lauric acid or myristic acid, ester or amides of fatty acids such as ethylene glycol monostearate, propylene glycol monostearate and glycerol monostearate, sorbitan fatty säureester as sorbitan monopalmitate, sorbitan monostearate and sorbitan tristearate, fatty alcohols such as cetyl alcohol, ethoxylated fatty alcohols, triglycerides, such as triglycerides of vegetable oils or modified vegetable oils, petroleum or mineral waxes such as paraffin, alkylene glycols, in particular solid at room temperature ethylene glycols and propylene glycols. Particularly preferred are stearic acid esters such as ethylene glycol and propylene glycol monostearate and sorbitan tristearate, and hydrogenated triglycerides of coconut and oil palm (e.g. Wecobee FS from Stepan).

The active component, which is to be encapsulated or dissolved in the matrix-forming material, is characterized by an extremely low solubility in water and a high solubility in hydrophobic liquids or solvents. If the active ingredient is a solid submicron particle like a pigment, it should be in the melt of the matrix-forming material. rials can be dispersed without significant agglomeration. If the active component is a solid or a liquid, it is preferably soluble in the melt of the matrix-forming material and results in a homogeneous mixture in the matrix-forming material. The active ingredient is preferably a lipophilic liquid.

The vapor pressure of the active ingredient is sometimes low or the active ingredient is sometimes solid at room temperature and not soluble in the matrix-forming material of choice. The active ingredient can also be in the form of particles that are too large to be successfully encapsulated. In such cases, the active ingredient can first be dissolved in a water-immiscible liquid which is capable of giving a homogeneous mixture with the molten matrix-forming component and then being allowed to remain in the dispersion. Suitable carrier liquids include solvents such as tributyl citrate, dioctyl phthalate, pine oil, etc.

The active component encapsulated by the matrix-forming material is a) a solid particle with a size smaller than 1 μm (sub-micrometer particles), b) a solid or a liquid which is produced in the melt of the matrix-forming material or c) a solid or a liquid which has been dissolved in a carrier liquid which is immiscible with water during manufacture.

Suitable active ingredients include, for example, all coloring components, skin-care or skin-protecting components and fragrances. It is irrelevant whether the active ingredient as such is solid or liquid at room temperature. These include in particular the colorants approved for cosmetic products, especially those for lipsticks. Examples include fat-soluble dyes such as fat brown B (casella), various food dyes (such as the naturally-synthesized food coloring agent ß-carotene oil-soluble, liquid (E160a) from Riedel aroma), possibly on a natural basis, Pigments and pigment preparations.

Also included are essential oils such as bergamot oil, Cedernholz- and -blattöl, citronella oil, eucalyptus oil, pine needle oil, Ka il- Lenoel, camphor, Kierfernnadelöl, spearmint, Latschenkie- remote oil, lavender oil, balm oil, Nelkenblätter- and -blütenöl, orange oil, pepper oil, peppermint oil , Rose oil, cinnamon oil and lemon oil.

Furthermore, caring substances such as oil-soluble vitamins, avocado oil, jojoba oil, aloe vera extract in an oily preparation, panthenol, walnut oil, tocopherol (vitamin E), tocopherol acetate, hydrogenated peanut oil, sweet almond oil, wheat germ oil, coconut oil, soybean oil, calendula oil Evening primrose oil, various plant extracts based on soybean oil, castor oil, various perfume oils and biobranil (concentrated extract from wheat bran) are suitable.

Active ingredients such as butylmethoxydibenzoylmethane, benzophenone-3, menthylbenzylidene ca pher, octyl ethoxycinnamate, octyldimethyl-PABA (or 2-ethylhexyl-4-dimethylaminobenzoate) and isoamyl-p-methoxycinnamate are also suitable as sun protection components.

The active component encapsulated by the matrix-forming material is preferably a UV-absorbing material, an essential oil, an organic dye, an organic or inorganic pigment, a lubricating oil, a fragrance or a flavoring agent and is particularly selected from pine oil, peppermint oil , substituted or unsubstituted cinnamic acids or substituted or unsubstituted cinnamic acids esters, triazole Compounds, organic dyes, inorganic pigments, perfume oils, derivatives of γ-linolenic acid, vitamins such as vitamins E and A or skin softening agents.

The active ingredient is therefore preferably, for example, a colorant for a wide range of dyeing or coating applications or a chemical which is to be released in a controlled manner, for example to improve breathing or to keep the skin moist. Suitable active ingredients include UV absorbing materials such as substituted or unsubstituted cinnamic acids and their esters, formamidine compounds, triazole compounds and those compounds which are used as optical brighteners, and organic and inorganic dyes, organic and inorganic pigments such as micronized titanium dioxide, micronized zinc oxide and iron ferrocyanide, lubricating oils such as skin softening agents, fragrances and substances such as perfume oils (for example lavender, pine oil, clove oil, peppermint oil and the like).

The active ingredient can be present in widely varying concentrations, but the ratio of active ingredient to encapsulating matrix material is preferably in the range from about 1:25 to 25: 1, preferably 1:10 to 10: 1. If a carrier is used, in order to dissolve the active ingredient, the active ingredient should preferably be present in the carrier in a concentration of about 0.5 to 95% by weight, preferably 1 to 90% by weight and more preferably 2 to 85% by weight.

The active ingredient is typically insoluble in water, but is soluble in the matrix-forming material so that it does not pass into the aqueous phase when an aqueous emulsion or dispersion is formed. The matrix-forming material used influences the emulsion and dispersion behavior in water and serves to store, protect and transport the active component in an environment in which it would otherwise be would not be stable at all or only to a limited extent due to solubility, oxidation or other factors.

An essential feature of the present invention is therefore also that the active ingredient, when embedded or encapsulated in the matrix-forming material, can be stable in an aqueous solution and cannot be released before the particle is placed in a suitable, e.g. lipophilic, environment arrives.

Depending on the chemical nature of the active ingredient, it may be due to physical forces that are exerted when the composition is applied to the desired substrate, e.g. the skin to be applied are released from the matrix-forming material. Alternatively, the active ingredient can be released by evaporation after removal of the surrounding water. Furthermore, it can be released from the matrix-forming material after a change in the chemical, biological or physical environmental conditions. The release can therefore possibly include mechanisms such as diffusion through the matrix material and / or increased solubility of either the active component or the matrix material in the target environment.

Suitable substrates to which the composition according to the invention or the dispersion according to the invention can be applied include, for example, human skin, fingernails and toenails or hair substrates. The cosmetic compositions or dispersions according to the invention can serve as such as cosmetic preparations or can be used to produce such preparations.

According to the method according to the invention, particles in the submicron range (size <1 μm) are produced which contain an active ingredient which is stored, stabilized or stabilized in a hydrophilic, ie water-containing environment can be transported and then released by deliberate change of environment.

Furthermore, the particles can be formulated in such a way that they show the desired surface and physical properties, which in turn are independent of the chemical or physical properties of the enclosed active ingredient. The active ingredient is preferably evenly distributed in the matrix material or surrounded by the matrix material as a shell.

The rheology and the ability to control the dispersion stability with respect to both the flocculation and the suspension of the submicroscopic, dispersed particles is significantly improved overall. The stability and the rheological properties of an aqueous dispersion are therefore largely predictable, and knowledge of the physical and chemical properties of the matrix-forming material can be used, these properties not being significantly influenced by the nature or the amount of the active ingredient .

For example, if the active ingredient is a skin-penetrating and moisturizing compound that is to be applied to the skin and then mediated through a lipophilic delivery system, higher concentrations of this compound are possible than when water-based delivery systems are used, which is based on the solubility limits in water. Another important aspect is that the particles can be formulated more easily so that they show the desired properties, such as, for example, the particle sizes, film-forming properties or adhesive properties, and properties such as gloss and abrasion resistance.

In contrast to the prior art, the present invention provides acceptable physical and chemical Properties of the active ingredient, desirable ratios of active ingredient to the matrix-forming material and the choice of suitable matrix-forming materials larger areas. The present invention enables these advantages without the need for an intermediate solvent and the associated need for removal and disposal.

Furthermore, according to the invention, matrix-forming materials are used which can easily be formulated in such a way that they can control the release rate of an enclosed active component in a targeted manner. A possible explanation for this phenomenon is that the diffusion rate of an active component through the surrounding matrix can be controlled primarily by the physical interaction of the active component with the matrix material.

The composition particles of matrix and active ingredient have a size smaller than 1 μm and preferably an average size of 500 to 5 nm, in particular 200 to 5 nm or even less.

It is preferred that at least one particle of the active ingredient is present in each particle of the matrix-forming material, or that the active ingredient is dissolved in the matrix-forming material. The ratio of active ingredient to matrix-forming material is preferably in the range from 0.04 to 25, more preferably 0.1 to 10, which corresponds to a ratio of 1:25 to 25: 1, more preferably 1:10 to 10: 1.

The solid particles of matrix material and the active ingredient enclosed therein can be dispersed in an aqueous medium and accordingly form an aqueous dispersion which can be used as or for the production of cosmetic products. The aqueous dispersion then preferably comprises 1.0 to 50% by weight, in particular 10 to 40 and preferably 20 to 30% by weight, of the solid, particulate cosmetic composition according to the invention as a discontinuous phase and, if appropriate, surfactant.

Suitable surfactant material which can be used according to the invention comprises anionic, cationic, amphoteric and non-ionic surfactants or mixtures thereof.

Examples of suitable surfactants include non-ionic surfactants such as polyethylene oxides, ethoxylated alkylphenols (eg nonylphenol polyoxyethylene), ethoxylated fatty acid esters, ethoxylated fatty alcohols (eg cetyl, stearyl, lauryl or tridecyl alcohol), ethoxylated glyceride esters, sorbitan esters (eg sorbitan tristearate) ), long-chain fatty acid esters from polyethylene glycols, diethanolamides, coconut fatty acid monoethanolamide, alkylaryl polyether alcohols, etc. Usable anionic surfactants include sodium lauryl sulfate, sulfosuccinic acid derivatives (eg disodium N-octadecylsulfosuccinate, disodium ethoxylated alcohol half ester of sulfosuccinic acid, disodium ethoxylated nonylphenol half ester of sulfosuccinic acid, diamyl ester of sodium sulfosuccinate sulfonate), diamyl ester of sodium sulfosuccinate sulfonate (I) Alcohol esters (for example ammonium salts of sulfated nonylphenoxy poly (ethylene oxy) ethanol), ammonium lignin sulfonate, lecithin and naturally occurring mixtures of diglycerides of stearic, palmitic and oleic acids which are linked to the quinoline ester of phosphonic acids. Useful cationic surfactants include quaternary ammonium salts, cetyl pyridinium chloride, polyalkylamidoimidazoline sulfate and ethanolized alkylguanidine amine complexes. Usable amphoteric surfactants include complex fatty amide compounds, modified fatty amine condensates and sulfobetaine compounds. Of these surfactants, non-ionic and anionic surfactants are preferred, in particular those selected from ethoxylated alkylphenols, ethoxylated alcohols. fetch, ethoxylated fatty esters, sulfosuccinic esters, sorbitan esters, alkyl and aryl sulfonates, lecithin and mono- and diglycerides of stearic, palmitic and oleic acids. Lecithin and the naturally occurring mixtures of diglycerides of stearic, palmitic and oleic acids are particularly useful tenides.

A production process for the composition according to the invention or the dispersion according to the invention which contains this composition is described below.

The first stage of the process comprises heating at least one water-insoluble, non-polymeric, matrix-forming material which is solid at room temperature and a water-insoluble, cosmetic, active ingredient to be encapsulated in the matrix. Heating is continued until a temperature is reached which is sufficient to melt the matrix-forming material, but is preferably lower than about 100 ° C., so as to form a hot melt which has a viscosity which is lower than about 500 mPas. The temperature is preferably kept in a range from about 60 to about 85 ° C., and again the mixture is preferably stirred with a mechanical stirrer during the heating.

The matrix-forming material essentially determines the density of the aqueous emulsion. Concentration ratios can be produced in a wide range in the aqueous emulsion in a simple manner by changing the ratios of the active ingredient to the matrix-forming material accordingly. The ratio of active ingredient to matrix-forming material is preferably in the range from about 0.1 to 10.0.

The density of the composition particles obtained in the end is a function of this ratio and the density of the matrix-forming material. During the heating, the active ingredient is dissolved in the hot liquefied melt of the matrix-forming material and dispersed therein. Preferably or if necessary, at least one surfactant is added to the hot melt before the melt is added to water in step 2). The choice of surfactant, if used, depends essentially on the chemistry and surface properties of the active ingredient. However, a wide variety of surfactants can be used as long as they have the ability to wet the active ingredient in the hot melt or to reduce the interfacial tension between the hot melt and the water in stage 2).

After heating in stage 1), the hot melt is added to water in an amount such that a concentration in the range of preferably 1 to 50% by weight, in particular 10 to 40% by weight and more preferably 20 to 30% by weight results. The surfactant, which is optionally present when the hot melt is added to water while moving (stage 2), can be combined with the hot melt, previously added to the water to which the hot melt is added, or both . At least one surfactant is preferably combined with the hot melt in stage 1) and then another surfactant or an additional amount of the same surfactant is added to the water to which the hot melt is added. When adding the hot melt, the aqueous phase should be at the same temperature level in order to avoid a "temperature shock". If a surfactant is added to the water, it can be added either before or simultaneously with the addition of the hot melt. In any case, the presence of a surfactant when added in stage 2) is advantageous in order to reduce the interfacial tension between the hot melt and the water to a value of less than about 10 dynes / cm, preferably less than 5 dynes / cm , which further facilitates the production of a stable aqueous emulsion. Although the relative concentrations of all constituents can vary considerably, suitable aqueous emulsions are typically prepared if the relative concentrations fall into the following ranges, the data being based on 100 g of the particle emulsion:

matrix-forming material such as, for example, propylene glycol monostearate and sorbitan tristearate, a total of about 0.1 to about 50 g,

active ingredient such as liquid pine oil or a solid dissolved in a suitable solvent, a total of about 0.1 to about 50 g,

Surfactant such as sorbitan tristearate from about 0 to about 25 g and

Water, optionally containing up to about 10% additional surfactant such as disodium ethoxylated alcohol half ester of sulfosuccinic acid, at least 40 g.

The sufficient movement of the hot melt in the water during the emulsification in stage 2) can be achieved by a number of commercially available devices such as, for example, ultrasound devices, in particular ultrasound heads, high-speed stirrers, mixers or suitable homogenizers.

Preferably the agitation is caused by ultrasound in order to obtain an aqueous emulsion with very small droplets. (Sound output power max. 350 W with adjustable power output, eg 20 to 40% output power, sonication time 30 seconds to 5 minutes with a 100 g batch). The droplet size in the aqueous emulsion obtained is on average smaller than 1 μm, preferably is on average 500 to 5 nm, more preferably 200 to 5 nm or even less. The aqueous emulsion should be stable for at least two hours after it is made. If the emulsification in stage 2) has led to a sufficiently homogeneous mixture, the aqueous emulsion has a stable discontinuous phase, which has an average size of less than 1 μm, and a continuous aqueous phase (water).

The time required to produce the desired droplet size varies with the type of device used, the amount of hot melt and water used and the interfacial tension between the hot melt and water. In general, a time of at least two minutes, preferably about four minutes, is required if ultrasound is used, an average drop size of <1 μ can be achieved and 100 g are to be treated. In a preferred embodiment, the drops have an effective average size of approximately 500 nm or less, more preferably approximately 200 n or less and particularly preferably approximately 5 nm or less, which is achieved by means of an electron microscope, laser diffraction or on the basis of the zeta determined Potential can be demonstrated.

A subsequent lowering of the temperature of the system to, for example, room temperature leads to the solidification of the emulsion drops and the formation of spherical solid matrix particles which contain the active ingredient. The cooling in stage 3) is preferably carried out at a cooling rate of about 0.5 to 15 ° C., in particular 1 ° C. to about 10 ° C. and preferably 2 to 5 ° C. per minute. The cooling is achieved, for example, by simply allowing the aqueous emulsion to cool to room temperature, actively cooling it from the outside, or cooling it internally by adding additional water, this added water having a lower temperature than the emulsion.

The particles formed in this way are stable with regard to flocculation and sedimentation, show good dispersibility and, like before, the droplets have an average particle size. diameters of less than about 1 μm, preferably in the size range from about 5 to 500 nm, more preferably in the range from about 5 to 200 nm, and in some cases are even smaller. Furthermore, at least one particle of the active ingredient is preferably present as a core in each matrix particle or it is dissolved in the matrix material.

All or each of stages 1), 2) and 3) can be carried out under controlled pressure conditions if this is suitable, which is the case if a volatile active component is used. In a similar manner, all stages or each of the stages can be carried out under a suitable inert gas such as nitrogen, helium or argon if the active ingredient is sensitive to oxygen.

The exact formulation determines the release rate of the active ingredient in response to changes in the environment. In particular, the diffusion rate is influenced by the solubility of the active constituent in the matrix-forming material, the ratio of matrix-forming material to active constituent, the solubility of active constituent under changed ambient conditions and the rate of degradation of the matrix. Furthermore, the size of the particles is directly related to the total surface area of the particles that is available for release. The particle size could be a function of the amount of surfactant used, which additionally controls the interfacial tension between the hot melt and the water, and the amount of energy necessary to obtain a desired degree of emulsion of the hot melt in the water.

It is believed that the active ingredient can be released into a desired environment in a controlled manner by one or more of the following mechanisms:

(1) If the active ingredient has a sufficiently high vapor pressure, by diffusion through the matrix material wall, as Function of the radius of curvature of the particle and the vapor pressure of the active ingredient,

(2) when the active ingredient is dissolved in a carrier liquid within the particle structure, by diffusion through the matrix material as a function of the vapor pressure of the carrier liquid when the carrier evaporates,

(3) when a new medium surrounds the particles in the target environment by diffusion of the active ingredient through the

Matrix material as a function of its solubility in the surrounding medium, for example in the case of fat or similar lipophilic substrates, or

(4) if physical influences such as pressure, heat, radiation, chemical or biological conditions exist in the target environment, by breaking down or breaking up the structure of the matrix material.

The invention is further illustrated by the following examples.

First of all, an exemplary basic formulation for a cosmetic dispersion according to the invention is given, which can be adapted to the respective specific application without leaving the scope of the invention.

Baslsdisperslon

wide range preferred range execution form

Matrix material

Propylene glycol monostearate 1.0 to 25% by weight 10.0 to 15.0% by weight 11.00% by weight %

Sorbitan tristearate 1.0 to 25% by weight 10.0 to 15.0% by weight 14.95% by weight

active ingredient 0.5 to 50% by weight 10.0 to 30.0% by weight 20.00% by weight

(if necessary with POE (20) sorbitan monolaurate) 0.5 to 2.0% by weight 1.0 to 1.5% by weight 1.00% by weight

Dispersion medium deionized water> 40% by weight 50 to 70% by weight 51.55% by weight

(optionally with disodium ethoxylated half ester of sulfosuccinic acid) 0.1 to 5% by weight 0.3 to 1.5% by weight 1.50% by weight

The presence of POE (20) sorbitan monolaurate can affect the feeling on the skin. POE (20) sorbitan monolaurate and disodium ethoxylated half ester of sulfosuccinic acid are not necessary components.

Production process for the basic dispersion:

The matrix material is heated until all components have melted. The active ingredient is added and the mixture is homogenized by stirring. The dispersion medium is preheated to 75 ° C., the head of an ultrasonic homogenizer is immersed in it at this temperature and the mixture of matrix material and active ingredient is slowly added. During the addition, treatment is carried out with ultrasound (350 W, 20-40% output power). Following the homogenization, the mixture is cooled to room temperature without further ultrasound treatment and, if necessary, with gentle stirring.

The specific exemplary embodiments specified below comprise such an aqueous base dispersion.

Example 1 (Facial Moisturizing Cream) The following constituents were processed into a cosmetic dispersion.

Part A deionized water 24.10% by weight

Methyl paraben 0.20% by weight

Sorbitol, 20% sol. 2.00% by weight

Propylene glycol 3.00% by weight Carbomer 940 (2% dispersion) 15.00% by weight

Triethanolamine, 99% 0.60% by weight

Part B dispersion containing skin care ingredients 55.00% by weight

Part C fragrances and preservatives to 100% by weight

The ingredients of Part A except triethanolamine were mixed and dispersed. The triethanolamine was then added. Part B was added with vigorous stirring. Part C was then added and stirring continued until a homogeneous dispersion was obtained. Part B :

1) mineral oil 5.45% by weight

2) Propylene glycol monostearate 9.50% by weight sorbitan tristearate 11.50% by weight glyceryl monostearate 7.27% by weight caprylic / capric acid triglycerides 7.27% by weight hydrogenated vegetable oils 2.73% by weight stearic acid 3.64% by weight Laureth- 23 1.45% by weight 3) deionized water 49.69% by weight disodium ethoxylated alcohol half ester of sulfonic succinic acid 1.50% by weight

The components listed under 2) were heated together until they had completely melted. Then the mineral oil mentioned under 1), which had been preheated to 75 ° C., was added and a homogenized mixture was prepared with stirring. The mixture of 1) and 2) was slowly added to the mixture of the components under 3), which had been preheated to 80.degree. Then gently stirred for 5 minutes and cooled to 35 ° C.

Example 2 (Liquid, tinted lotion (o / w emulsion for oily skin)) The following constituents were processed to give a cosmetic dispersion.

Part A Steareth-7 (and) 9.00 wt%

Stearyl alcohol (and) steareth-10

(Mixture = emulsifier E 2155) (Th. Goldschmidt AG)) isooctadecyl isononanoate 2.00% by weight (Tegosoft 189) (Th. Goldschmidt AG)

Isopropyl myristate 9.00% by weight (Continued part A)

Mineral oil 8.00% by weight

Stearyl dimethicone 2.50% by weight

(Abil Wax 9800) (Th. Goldschmidt AG)

Dimethicone 0.50% by weight

(Abil 100)

(Th. Goldschmidt AG)

Part B deionized water 3.00 wt% glycerin 2.00 wt%

Part C pigmented dispersion 40.00% by weight

Part D deionized water 23.50% by weight

Preservatives and

Fragrances to 100% by weight

The ingredients of Part A were mixed together while heating to 70 ° C. The deionized water from part D was also heated to 70 ° C. and added to part A. It was cooled, with homogenization by stirring. Thereafter, the mixed ingredients of Part B were added with stirring and when a temperature of 30 to 35 ° C was reached. The Dis _¬ persion of Part C was added subsequently with stirring so that a homogeneous formulation was formed. In the end, fragrances and preservatives were added.

Part C:

1) propylene glycol monostearate 10.00% by weight

Sorbitan tristearate 14.50% by weight

2) Talc 2.00% by weight

Titanium dioxide 5.00% by weight

Iron oxides 3.50% by weight

Ultramarine blue 0.15% by weight

3) deionized water 63.35% by weight

Disodium ethoxylated alcohol half of the

Sulfosuccinic acid 1.50% by weight The components of part 1) were heated together until they had completely melted. The components of part 2) were ground as necessary and dispersed in part 1) using an ultrasonic homogenizer. The constituents of part 3) were preheated together to 80 ° C. and then slowly mixed with the homogeneous mixture of part 1) and part 2), an immersed ultrasound head causing the desired dispersion. The dispersion was then cooled to ambient temperature with gentle stirring.

Example 3 (sunscreen lotion; o / w emulsion) The following constituents were processed into a cosmetic dispersion.

Part A UV protection dispersion 20.00% by weight

Part B stearic acid 3.00% by weight

Isopropyl myristate 3.00% by weight

Hexyl laurate 6.00% by weight sweet almond oil 2.50% by weight butylated hydroxytoluene 0.10% by weight

Part C DEA cetyl phosphate 3.00% by weight

Part D Phanthenol 1.00% by weight

Propylene glycol 3.00% by weight disodium EDTA 0.10% by weight deionized water 53.30% by weight

Part E deionized water 5.00% by weight

Preservatives and

Fragrances to 100% by weight

The components of Part B were heated to 85 ° C while stirring with a planetary stirrer. Part C was then added and a homogeneous mixture was prepared with continued stirring. A mixture of the components of Tei-D preheated to 75 ° C. was then also added with stirring. It was then cooled to 40 ° C and part E and optionally Water added to compensate for any loss of water. While cooling to ambient temperature, part A was stirred in, resulting in a homogeneous dispersion.

Part A:

1) octyl methoxycinnamate 20.00% by weight butylmethoxydibenzoylmethane 5.00% by weight

2) hydrogenated triglyceride

Coconut and oil palm 11.00 wt% sorbitan tristearate 14.50 wt%

3) deionized water 48.00% by weight

Disodium ethoxylated

Alcohol half of the

Sulfosuccinic acid 1.50% by weight

The components of part 2) were heated until they had completely melted. The mixture of the components from part 1), which had been preheated to 75 ° C., was added with stirring and homogenization. This homogeneous mixture was added to part 3), which had been preheated to 80 ° C., and was dispersed by means of an ultrasound head. The mixture was then cooled to ambient temperature with gentle stirring.

Example 4 (Perfume Oils)

The following ingredients were weighed, warmed and mixed:

1. 11.0% by weight of propylene glycol monostearate,

2. 14.6% by weight sorbitan tristearate, 3 3 .. 2 200, .00 G wt. %% perfume oil

4. 52.9% by weight of demineralized water and

5. 1.5% by weight disodium ethoxylated alcohol half ester of sulfosuccinic acid.

The above mixture was placed in a closed container and warmed and stirred carefully, heating in a water bath and continuing until all solids had melted. In this case, all components were weighed in a 1-phase approach and then heated together, or components 1 - 3 and 4 + 5 were heated separately and then mixed.

Then the emulsion was prepared by adding the hot melt to water while sonicating. The temperature was kept between 60 and 75 ° C. After a 4-minute ultrasound treatment, droplets with an average diameter of less than 500 nm were found. The aqueous emulsion was then slowly cooled to room temperature, causing the droplets to solidify.

The dispersion of the solid particles was applied to a substrate. In comparison with ethanolic or isopropanolic preparations of the same perfume oil, the scent was retained for a significantly longer time.

Example 5

(UV absorber) The following compounds were mixed by the process of the preceding example:

8.2% by weight of a mixture of mono- and diglycerides from

Palmitic and stearic acids, 11.0% by weight of purified, hardened palm oil, 15.0% by weight of 2-ethylhexyl p-methoxycinnamate, 64.6% by weight of demineralized water and 1.2% by weight of disodium ethoxylated alcohol half-ester from

Sulfosuccinic acid.

The heating and emulsification was carried out according to the method described. The resulting solid particle dispersion provides. ; excellent UV protection over a long period of time. Example 6 (Essential Oils) Following the procedure of the previous examples, the following compounds were mixed:

12.0% by weight of ethylene glycol monostearate, 10.0% by weight of sorbitan tristeart, 12.0% by weight of a mixture of essential oils, 64.5% by weight of demineralized water and 1.5% by weight of disodium ethoxylated alcohol half ester from

Sulfosuccinic acid.

The heating and emulsification were carried out in accordance with the method described above. When applied to a substrate, the scent of the essential oil remained much longer than with a standard oil-in-water emulsion of the same concentration.

Example 7 (Vitamin A)

Following the procedure of the previous examples, the following compounds were mixed:

6.0% by weight hydrogenated fatty acid from rapeseed oil, 19.6% by weight sorbitan tristearate, 5.0% by weight vitamin A, 67.9% by weight demineralized water, 1.5% by weight disodium ethoxylated alcohol half-ester of sulfosuccinic acid.

The heating and emulsification were carried out as before, except that an inert gas atmosphere was used to prevent oxidation. The resulting particle dispersion contained the vitamin in a stabilized form that is far less sensitive to oxidation than an unencapsulated form. Example 8 (. Scent dispenser (liquid, active ingredient)) 15 g of a solid, hydrogenated vegetable oil (commercially available from Stepan Co. under the trade name WECOBEE SS) and 5.0 g of solid stearic acid (commercially available from Eastman Kodak Comp. ) were weighed into a vessel. To this was added 10.0 g of lavender essence (commercially available from Reynaud Ltd. under the trade name R 152). The container was tightly sealed so that no volatile component could escape. (This can be done, for example, by using a heat-resistant sealing film). The sealed container was then placed in a 70 ° C oven until all of the components had melted. 60.0 g of ionized water and 3.0 g of surfactant, namely the ammonium salt of sulfated nonylphenoxypoly (ethyleneoxy) ethanol (commercially available from GAF under the trade name Alipal EP 110) were weighed into a second container, the container was covered and placed in a 70 ° C oven until the container reached this temperature. Then both containers were removed from the oven and the mixtures contained therein were each homogenized. Without being able to cool down, an ultrasonic homogenizer was added to the water mixture and the liquefied mixture of lavender oil / vegetable oil matrix was slowly added. An emulsion of the lavender / vegetable oil mixture formed in the water. An ultrasound sonication was carried out until a microscopic inspection showed that the emulsion drop size was uniform and below 1 μm. The emulsion was then gently stirred until the liquid reached room temperature, causing the lavender / vegetable oil mixture to solidify and a stable dispersion to result.

The dispersion was useful for making water-based cosmetics. It provided a pleasant smell for a long time, which was much longer than that obtained with an unencapsulated lavender oil.

Claims

claims

1. A cosmetic composition comprising a) a solid, particulate water-insoluble matrix of at least one water-insoluble, non-polymeric, matrix-forming material which is solid at room temperature, and b) a water-insoluble, cosmetically active ingredient encased in the matrix, wherein the matrix particles have an average size of about 1μ or less.

2. Composition according to claim 1, characterized in that the at least one matrix-forming material is selected from vegetable oils, in particular hardened palm oil, hydrated triglycerides of coconut and oil palm, cotton oil, castor oil and esters of the same, animal waxes such as tallow, oil Nene wax, whale wax or aqueous lanolin, fatty acids such as stearic acid, lauric acid or myristic acid, esters or a idene of fatty acids such as ethylene glycol monostearate, propylene glycol monostearate and glycerol monostearate, sorbitan fatty acid esters such as sorbitan monopalmitate, sorbitan alkoxylate, fatty acid alkoxylate, fatty acid alkoxylate, fatty acid alkoxylate, fatty acid alkoxylate, fatty acid alkoxylate, fatty acid alkoxylate such as triglycerides of vegetable oils or modified vegetable oils, petroleum or mineral waxes such as paraffin and alkylene glycols such as ethylene glycols and propylene glycols which are solid at room temperature.

3. Composition according to claim 1 or 2, characterized gekennzeich¬ net that the encapsulated by the matrix-forming material active ingredient a) is a solid particle with a size smaller than 1 micron b) is a solid or a liquid which has dissolved in the hot melt of the matrix-forming material during manufacture, or c) is a solid or liquid which has been produced in a water-immiscible form

Carrier liquid has been dissolved.

4. Composition according to one of claims 1 to 3, characterized in that the active ingredient encapsulated by the matrix-forming material is a UV-absorbing material, an essential oil, a vitamin, an organic dye, an organic or inorganic pigment, is a lubricating oil, a fragrance or a flavoring and is particularly selected from pine oil, peppermint oil, substituted or unsubstituted cinnamic acids or substituted or unsubstituted cinnamic acid esters, triazole compounds, organic dyes, inorganic pigments, perfume oils, derivatives of γ-linolenic acid, vitamins, in particular vitamins E and A, or skin softening agents.

5. Composition according to one of claims 1 to 4, characterized in that the particles of matrix and active ingredient have an average size of 500 to 5, in particular 200 to 5 nm or even less.

6. Composition according to one of claims 1 to 5, characterized in that at least one particle of the active ingredient is present in each particle of the matrix-forming material.

7. Composition according to one of claims 1 to 6, characterized in that the ratio of active ingredient to the matrix-forming material is in the range from 0.04 to 25, in particular 1 to 10.

8. Aqueous dispersion comprising a solid, particulate composition according to one of claims 1 to 7.

9. Aqueous dispersion according to claim 8, characterized in that it comprises 1.0 to 50.0% by weight of solid, particulate composition as a discontinuous phase and optionally surfactant.

10. Aqueous dispersion according to claim 8 or 9, characterized in that the surfactant comprises anionic, cationic, amphoteric or nonionic surfactant or a mixture thereof and is selected in particular from ethoxylated alcohols and ethoxylated alkylphenols, ethoxylated fatty acid esters, sulfosuccinic acid esters, sorbitan esters , Alkyl and aryl sulfonates as well as mono- and diglycerides of stearic, palmitic and oleic acids.

11. A method for producing a composition according to any one of claims 1 to 7 or an aqueous dispersion according to any one of claims 8 to 10, characterized in that

1) at least one water-insoluble, non-polymeric, matrix-forming material which is solid at room temperature and a water-insoluble active component to be encapsulated in the matrix are heated together to a temperature which is sufficient for the matrix-forming

Melting material,

2) the hot melt formed from the matrix-forming material and the active ingredient is added to water with agitation, optionally with surfactant being present to produce a stable aqueous emulsion, the matrix-forming material with the active ingredient enclosed therein in the form of droplets with an average Size of about 1 micron or less, and 3) the stable, aqueous emulsion is cooled to room temperature to form an aqueous dispersion of solid components. obtained from matrix-forming material with encapsulated active ingredient, which is then optionally removed from the water.

12. The method according to claim 11, characterized in that the at least one matrix-forming material is selected from vegetable oils, in particular hardened palm oil, hydrogenated triglycerides of coconut and oil palm, cotton oil, castor oil and esters thereof, animal waxes such as tallow, bees Nene wax, whale wax or aqueous lanolin, fatty acids such as stearic acid, lauric acid or myristic acid, esters or amides of fatty acids such as ethylene glycol monostearate, propylene glycol monostearate and glycerol monostearate, sorbitan fatty acid esters such as sorbitan monopalmitate, sorbitan alcohol alkistearene, fatty alcohol alkostearate, ethoxylated fatty alcohols such as fatty alcohol, fatty acid alkoxylates such as fatty alcohol alkostearenes, fatty alcohol tristalkenes, fatty alcohol alkostearenes, fatty alcohol alkostearenes, fatty alcohol alkoxylates such as fatty acids Triglycerides of vegetable oils or modified vegetable oils, petroleum or mineral waxes such as paraffin and alkylene glycols such as ethylene glycols and propylene glycols which are solid at room temperature.

13. The method according to claim 11 or 12, characterized in that the active ingredient to be encapsulated by the matrix-forming material a) is a solid particle with a size smaller than 1 μm b) is a solid or a liquid which / in the manufacture in the hot melt of the matrix-forming material is soluble, or c) is a solid or a liquid which is dissolved in a carrier liquid which is immiscible with water.

14. The method according to any one of claims 11 to 13, characterized ge indicates that the active ingredient to be encapsulated by the matrix-forming material is a UV-absorbing material, an essential oil, a vitamin, an organic coloring agent. Substance, an organic or inorganic pigment, a lubricating oil, a fragrance or a flavoring and is particularly selected from pine oil, peppermint oil, substituted or unsubstituted cinnamic acids or substituted or unsubstituted cinnamic acid esters, triazole compounds, organic dyes , inorganic pigments, perfume oils, derivatives of γ-linolenic acid, vitamins, in particular vitamins E and A, or skin softening agents.

15. The method according to any one of claims 11 to 14, characterized ge indicates that at least one surfactant is added to the hot melt before the melt in stage 2) is added to the water and / or the water to which the hot melt in Level 2) is given, contains at least one surfactant.

16. The method according to any one of claims 11 to 15, characterized ge indicates that the surfactant comprises anionic, cationic, amphotheric or nonionic surfactant or a mixture thereof and is selected in particular from ethoxylated alcohols and ethoxylated alkylphenols, ethoxylated fatty acid esters, Sulfosuccinic acid esters, sorbitan esters, alkyl and aryl sulfonates and mono- and diglycerides of stearic, palmitic and oleic acids.

17. The method according to any one of claims 11 to 16, characterized ge indicates that at least one surfactant is added to the hot melt in stage 1) and then to the water to which the hot melt is added in stage 2) before or equal to in time with the addition of the hot melt to the water either another or the same surfactant is added.

18. The method according to any one of claims 11 to 17, characterized ge indicates that the movement in stage 2) is effected by treatment with ultrasound, this treatment being carried out in particular 0.1 to 30 minutes and preferably for about 4 minutes.

19. The method according to any one of claims 11 to 18, characterized ge indicates that the interfacial tension between the droplets of matrix-forming material with the active ingredient therein and the water is less than about 10 dynes / cm.

20. The method according to any one of claims 11 to 19, characterized ge indicates that the droplets of matrix and active ingredient receive an average size of 500 to 5, in particular 200 to 5 nm or less.

21. The method according to any one of claims 11 bit 20, characterized in that at least one particle of the active ingredient is present in each particle of the matrix-forming material.

22. The method according to any one of claims 11 to 21, dad * indicates that the ratio of active bestan. 1 for the matrix-forming material in stage 1) is in the range from Λ to 25 (= 1:25 to 25: 1).

23. The method according to any one of claims 11 to 22, characterized ge indicates that the cooling in stage 3) takes place at a cooling rate of 1 ° C to 10 ° C per minute.

24. The method according to any one of claims 11 to 23, characterized ge indicates that the cooling in stage 3) is achieved by adding additional water to the aqueous emulsion, this additional water having a lower temperature than the emulsion.

25. The method according to any one of claims 11 to 24, characterized ge indicates that the matrix-forming material in stage 1) is heated to a temperature below 100 ° C, in particular 60 to 85 ° C, this temperature during the movement in stage 2 ) is maintained.

26. The method according to any one of claims 11 to 25, characterized in that it is carried out under inert gas.

27. The method according to any one of claims 11 to 26, characterized in that the hot melt has a viscosity which is less than about 500 mPas.

28. Use of a composition according to one of claims 1 to 7 or a dispersion according to one of claims 8 to 10 as / in cosmetic product (s) or for the production of cosmetic products.