FR2996768A1 - Preparing cosmetic ball that is applied to e.g. skin of human body, comprises preparing basic solution using first polymer, mixing cosmetic active agent with basic solution, and performing spherification process - Google Patents

Abstract

Preparing a cosmetic ball comprises: preparing a basic solution using a first polymer that is ready to form a structure according to an egg box model; mixing a cosmetic active agent with the basic solution; preparing a spherification bath with a component source of divalent ions; and performing the spherification of the basic solution mixed with the cosmetic active agent, where an upper mass concentration of the polymer in the basic solution is 5 g/l, and the spherification process is performed with the component of divalent ions having a mass concentration >= 0.7 g/l. An independent claim is included for a cosmetic ball prepared using a method.

Description

Process for obtaining cosmetic beads, beads obtained and use of such beads. The field of the invention is that of cosmetology. More specifically, the invention relates to a process for obtaining cosmetic formulations, in particular but not exclusively without excipient, dispensed in unit dose form. In the field of the invention, a formulation is defined as a preparation resulting from a mixture of different raw materials, in order to respond to a demand expressed, in general, in terms of properties. In addition, a cosmetic product or active ingredient corresponds to any substance or mixture intended to be put in contact with various superficial parts of the human body, in particular the epidermis, the hair and hair systems, the nails, the lips, etc. view of the 15 clean, protect, perfume, maintain in good condition, modify their appearance or smell. Cosmetics are hygiene and beautification products that remain superficial in their actions, not acting below the barrier of the epidermis. The conventional composition of a contemporary cosmetic formulation is as follows: surfactants, water-soluble polymers, thickeners, preservatives, antibacterials, antiseptics, emollients and moisturizers, pigments, propellants, perfumes, dyes, various additives. Among the manufacturers of cosmetics, some seek to offer mainly, or even exclusively, nature-friendly products, containing no preservatives or synthetic additives, and being particularly rich in active plant ingredients. Conventionally, products of this type incorporate high levels of vegetable oils, associated with the benefits of essential oils.

Moreover, in the field of pharmacology or biotechnology, it is known to encapsulate in particular active ingredients in order to target their diffusion in the body. As such, encapsulation techniques are nowadays more and more 5 explored and used. Recently, these techniques have been reconsidered for the development of molecular cuisine for which we then speak of spherification. This technique consists in the controlled gelation of a liquid which, immersed in a bath, will form spheres. There are two types of spherification: basic spherification or normal phase encapsulation (which consists of immersing a liquid supplemented with a gelling agent in a spherification bath) and inverse spherification, where a liquid will be immersed for example at calcium gluconalactate, a mixture of two calcium salts (calcium gluconate and calcium lactate) in a gelling bath. These methods make it possible to obtain spheres of different sizes. Normal encapsulation is a method that makes it possible to obtain semi-solid pearls of homogeneous consistency, in which the asset to be encapsulated is dissolved. It makes it possible to obtain pearls without residual solid capsule on the surface. This technique, also known as the extrusion method, consists of dropping a solution containing a gelling agent into a spherification bath containing a high concentration of calcium ions (calcium lactate or calcium carbonate) 25 A on an industrial scale, this type of process is carried out by devices equipped with a system for pumping alginate solution, propelled in a calcium bath by extrusion through adjustable diameter, vibrating nozzles (intensity of adjustable vibration), and with controlled flow. The vibrations of the drip system 30 make it possible to obtain small balls of relatively constant diameter.

In a very widespread manner, the solution used to form beads in the spherification bath is a solution of sodium alginate. From algae, alginates are natural polymers with structural roles. They are found in cells and in the extracellular matrix where they represent about 40% of the dry mass. They are for aquatic plants, what cellulose is for terrestrial plants. They give them the rigidity or flexibility necessary to withstand the stresses of their natural environment (currents, pressure ...). Their basic structure is composed of unbranched polysaccharides: p-D-mannuronic acid (M) and α-L-guluronic acid (G), which are interconnected. Mainly extracted from the species Laminaria, Ascophyllum, and Fucus, which are harvested in Norway, Australia, Japan, France or South America, these polymers are in the form of fine and white powders. These are the natural thickeners most widely used in the medical, pharmaceutical, bioprocesses, or even food ... They form indeed biocompatible and thermally stable gels in the presence of calcium ions, and they bring solutions for medical encapsulation. They serve as efficient vector systems in the controlled release of drugs or living materials such as cells, enzymes or hormones. Food or cosmetic side, alginates are used for their thickening, stabilizing and gelling properties, but they are also found in the encapsulation of oils, flavors, or perfumes. They are indicated under the name E401. Along the length of the polymer, the distribution of the M and G motifs is observed: three types of different sequences are found: alternating M and G patterns, consecutive GG patterns, and consecutive MM patterns.

It is important to note that it is this distribution of the different structural blocks of alginate that defines its physical properties. Indeed, the constituent polysaccharides of the polymer are in the carboxylate form in the molecule and must therefore be stabilized by a counter-ion. When it is a monovalent cation such as Na +, an ion stabilizes a carboxylate (C00-). The molecules, free in solution, then form fluid solutions. On the other hand, when it is a divalent cation, such as Ca2 +, Sr2 +, or Ba2 +, the counter-ion stabilizes two C00-, thus creating bridges between the different polymers (model of the "box" to egg "). These specific links allow the formation of rigid "branched" structures. However, these dimerizations are observed only between the guluronic residues of two polymer chains, hence the need to have a sequence of at least 6 to 10 G units which follow each other. When the ratio calcium / carboxyl group is sufficient, the complexes formed become insoluble and can then create fibers, films or capsules. The rigidity of the gel formed is therefore proportional to the quantity and the length of the GG blocks in the alginate, as well as to the proportion of monovalent or divalent ions. The other two types of motifs (MGMG or MMMM) are not involved in this type of interaction. They then form, whatever the operating conditions, relatively flexible portions.

However, if the viscosity of the alginate gel is constant when its pH is between 6 and 8, it increases significantly when the solution is acidified (pH less than 3.5). Under these conditions, numerous H bonds are formed and predominate over the repulsive electrostatic forces of the molecules, which contributes to the increase of the viscosity of the gel. This is therefore a special case of thick gel formation with sodium alginate.

The "egg box" model, described for the first time by Morris et al. in 1973, explains the branching and dimerization of alginate molecules, in the presence of divalent ions.

This model highlights the association of two GG blocks via divalent cations, calcium ions most often. By balancing the charges carried by the units G, these ions make it possible to create links between the polymer chains. Studies have shown a ratio of 4: 1 between G units and Ca2 + ions. The monomers are organized around the Ca2 + ions, forming egg-shaped structures. Only GG blocks would be responsible for the formation of these structures. Indeed, the conformation of the units G makes it possible to obtain folded GG blocks on themselves, and thus forming structures that can trap the Ca2 + ions (as illustrated by the figurel, (R. Stojanovic, A. Belscak-Cvitanovic , V. Manojlovic, Encapsulation of Thyme (Thymus serpyllum L.), aqueous extract in calcium alginate beads, J Sci Food Agric., 2011)). The state of the art reveals numerous encapsulation processes in alginate beads. The existing techniques are however not dedicated to cosmetic applications, and are in any case not suitable for cosmetic applications. Indeed, the methods described by the prior art have one or more of the following disadvantages: they do not make it possible to obtain well-spherical beads 25 and having a good behavior over time; they are not suitable for obtaining beads whose application to the skin can be immediate, without leaving capsule residues on the skin; the balls obtained are either too hard and inapplicable on the skin, or too fragile; the procedures must be reviewed, or even redesigned, with each modification of the formula, because of changes in the physicochemical and organoleptic properties of the beads; they do not make it possible to ensure a good conservation of the products and a stability of the textures; they are difficult to reconcile with the use of natural raw materials, in particular from organic farming, which do not undergo any chemical purification treatment and are inherently unprocessed and uncalibrated, which gives them variables depending on their supply, especially in terms of chemical composition, odor, color or texture. The invention particularly aims to overcome the disadvantages of the prior art.

More specifically, the object of the invention is to propose a spherification method suitable for transforming cosmetic formulations so as to propose them in encapsulated form allowing a mode of distribution of a unit dose application in the form of a ball.

The invention also aims to provide such a method that is adapted to the use of natural raw materials, in particular from organic farming. Another objective of the invention is to propose a new mode of application and distribution of cosmetic products.

These objectives, as well as others which will appear later, are achieved thanks to the invention which relates to a process for obtaining cosmetic beads, of the type comprising the steps of: - preparing a basic solution incorporating at least one polymer capable of forming a structure according to the "egg box" model; - incorporate in the base solution at least one cosmetic active; preparing a spherification bath with a divalent ion source component; performing a spherification phase of the basic solution incorporating said cosmetic active agent (s); characterized in that: - the step of preparing the basic solution is carried out with at least one polymer present in the solution with a mass concentration greater than or equal to 5g / I; the spherification phase comprises a step of preparing a spherification bath made with a component present with a mass concentration greater than or equal to 0.7 g / l in divalent ions, said component being intended to react with said polymer of the solution basic. Thus, the invention provides a process for obtaining cosmetic products, providing the following advantages: the products are presented in the form of balls, spherical and regular; the beads obtained allow their immediate (or delayed) application and leave no residue on the skin; it ensures a good preservation of the active formula over time; it allows the incorporation of essential oil or vegetable oil type assets, this according to multiple possibilities, without it being necessary to fundamentally change the operating mode; - It leads to a product whose packaging and application to the skin are particularly original and attractive to the user. According to an advantageous embodiment, the method comprises an intermediate step of forming the beads consisting in dropping the basic solution incorporating said cosmetic active agent (s) in a cryogenic bath. Such an intermediate step makes it possible to form a considerable number of balls at one time.

Indeed, the solution consisting in causing the base solution to drop directly into the concentrated divalent ion spherification bath produces a semi-batch process, which necessitates: - allowing the beads to drip for 20 to 30 seconds in the spherification bath concentrated in divalent ions, - allow the balls to bubble for 1 to 2 minutes before recovering them, - rinse the beads - repeat the operation as many times as necessary to reach the desired quantity of beads. Admittedly, this technique remains possible without departing from the scope of the invention. However, with the intermediate step using the cryogenic bath, it is possible to continuously pour a relatively large amount of the base solution into the cryogenic bath. All of the cryopreserved beads are then dipped at once into a divalent ion concentrated spherification bath, from which they are also recovered at once to be all rinsed and conditioned.

Thus, thanks to the implementation of such an intermediate step, the following advantages are obtained: less handling of the base solution and / or the beads and / or the spherification bath concentrated in divalent ions: the result is time saving ; - more precise information on the time spent by the balls in the divalent ions concentrated spherification bath: all the balls remain there exactly the same time (which is not the case in the case of the drip directly in the bath spherification concentrated in divalent ions which generates a difference of the order of 30s between the first drops and the last formed); - possible preservation of cryopresilized, non-spherified beads (basic solution simply fixed in nitrogen in the form of beads), this easily thanks to a simple freezer: no evolution or degradation of the beads, which preserves the possibility of achieving productions on demand, with great responsiveness. It is noted that, with the implementation of said intermediate step, the ball is no longer formed via its interaction with the divalent ions when it arrives in the spherification bath but by cryogenics. The formation of the ball is therefore caused by the solidification of the drop 15 when it enters the liquid nitrogen. The chemical process allowing the spherification occurs only afterwards, when the balls are immersed in the spherification bath concentrated in divalent ions. Advantageously, the duration of presence of the beads in the spherification bath is between 30 seconds and 3 minutes. Such a duration of presence in the spherification bath ensures that the beads have a sufficiently long life without agglomerating with each other, without reaching excessive hardness for application to the skin and without generating forming a film on the surface of the ball that would be likely to leave a residue on the skin. Preferably, the step consisting in preparing the spherification bath is carried out with calcium lactate at a mass concentration of calcium ions of between 0.7 g / l and 4.4 g / l. Such a spherification bath is very effective and allows to obtain homogeneous beads. The use of limewater as a spherification bath is however possible, but leads to more rigid beads, brittle and brittle than in a lactate solution.

It is important to note that the concentration of the calcium bath is to be expected as a function of the quantity of beads that it is desired to spherify (so as not to observe any depletion of the spherification bath before the total spherification of all the batch beads). Thus, stoichiometric amounts will be defined depending on the type of alginate used (amount of GG blocks) and the volume of beads per bath. According to an advantageous solution, the step of preparing a basic solution is carried out with at least one polymer capable of forming a structure according to the "egg box" model belonging to the following group: alginates; - carrageenans; Pectins; - gellan. According to a particular embodiment, the method comprises a step of adding a second polymer in the base solution. In this case, said second polymer is preferably viscose, xanthan type, and has no physical or chemical interaction with the polymer capable of forming a structure according to the model "egg box". With such a second polymer in the base solution, a support network is created which allows the homogeneous suspension of a fatty organic phase. It is then possible to increase the amounts of vegetable oils and / or essential oils, as well as the quantities of butter and / or solid vegetable oils. According to one characteristic of the invention, the process thus comprises a step of adding at least one active agent belonging to the following group: vegetable oil; - Essential oil ; - water soluble active; - fat-soluble active; - perfume; - flower water ; - dye. The invention also relates to a cosmetic ball obtained with a process as described above, characterized in that it comprises at least one cosmetic active belonging to the following group: - vegetable oil; - Essential oil ; - water soluble active; - fat-soluble active; - perfume; - flower water ; - dye. According to a preferred embodiment, such a ball comprises at least two distinct viscosity polymers. In this way, it is possible to provide cosmetic beads with relatively large proportions of natural products present in the form of a fatty phase, without excipient. According to an advantageous presentation, beads according to the invention are packaged in a container closed by a cap including a small spoon. Thus, the user is offered a packaging that facilitates the gripping and handling of the beads, while preserving the possibility of designing an aesthetically attractive container. The invention also relates to the use of a ball as described above, characterized in that it consists of, successively: - applying the ball to the skin; - press the ball against the skin until crushing the ball; - massage the skin with the ball crushed until complete penetration. Other features and advantages of the invention will emerge more clearly on reading the following description of a preferred embodiment of the invention, given by way of illustrative and nonlimiting example, and the appended drawings among which: FIG. 1 illustrates a polymer reacted with divalent ions to form a structure according to the "egg box" model; FIG. 2 schematically illustrates a device for carrying out a step of a method according to the invention; FIG. 3 illustrates in block diagram form the steps of a method according to the invention; - Figure 4 is a sectional view of a container for the packaging of beads according to the invention. With reference to FIG. 2, a device that can be used for carrying out a method according to the invention comprises: a pumping system 1 of a base solution 2 incorporating at least one polymer capable of forming a structure according to the "egg box" model, such as an alginate solution; one or more nozzles 3, preferably of adjustable diameter, vibrating (with a frequency and / or an amplitude of adjustable vibrations, these vibrations contributing to obtain balls having a relatively constant diameter), and with a controlled flow, to deliver the basic solution 2 drip; a tank 4 containing a bath, described below, intended to receive the drops of the basic solution delivered by the nozzle or nozzles 3. According to one conceivable embodiment, the tank 4 contains a spherification bath prepared with a divalent ion source component, in which the drops dabble for a few minutes until the beads of the desired hardness are obtained. According to a preferred embodiment, the tank 4 contains a cryogenic bath, in the form of liquid nitrogen, at -196 ° C.

Thus, in contact with liquid nitrogen, the drop (a priori round or almost) freezes instantly, forming a ball. It no longer evolves as long as it is stored at a maximum of -20 ° C. This step makes it possible to form a large quantity of balls at one time. Indeed, all of the basic solution 2 contained in the pumping system will be poured dropwise into the liquid nitrogen. At the end of this intermediate cryogenic step, all the cryogenic beads are dipped at once in the spherification bath prepared with a divalent ion source component. The balls are collected together for rinsing and conditioning. As illustrated by FIG. 3, the main steps of a process according to the invention are successively: step A: preparation of a basic solution incorporating at least one polymer capable of forming a structure according to the "box eggs "; step B: incorporate in the base solution at least one cosmetic active agent; step C: pour in dropwise the basic solution incorporating the cosmetic active ingredient in a cryogenic bath; step D: immerse the beads in a spherification bath prepared with a divalent ion source component; step E: remove the beads from the spherification bath; step F: rinsing the beads; step G: conditioning of the balls.

The method provides a step of preparing the base solution with at least one polymer present in the solution with a mass concentration greater than or equal to 5 g / l. The polymer at the origin of the spherification may be any dimerizable polymer (or mixture of such polymers) capable of forming stable, organized, bridged and branched structures with multivalent ions. In this category are all polymers allowing the formation of structure according to the "egg box" model: alginates, carrageenans (iota), pectins, gellan ...

In the case of a basic solution consisting of an alginate solution, the alginate concentration can vary from 0.5% by mass until saturation. In the case where it is planned to incorporate in the base solution a cosmetic active comprising a fatty phase, the method may comprise a step of adding a second polymer in the base solution. The second polymer is viscose, xanthan type, and having no physical or chemical interaction with the polymer capable of forming a structure according to the model "egg box". This addition aims to create a second structuring network.

It is therefore possible to use for this purpose any polymer or mixture of polymers having viscosifying properties, capable of creating a maintenance network for the additives (hydro and liposoluble) incorporated in the base solution, and which is inert or exhibiting only very few interactions with respect to the bivalent ions (or more) present in the medium: xanthan, guar gum, carob, konjac, gellan ... As indicated previously, the process involves the use of a spherification bath incorporating a divalent ion source component, and thus a step of preparing such a bath. According to the principle of the invention, this step of preparation of the spherification bath is carried out with a component (intended to react with the polymer of the base solution) present with a mass concentration greater than or equal to 0.7 g / l in divalent ions.

According to a preferred solution, the component of the spherification bath is a source of calcium. More specifically, the bath preparation is carried out with calcium lactate in a mass concentration of calcium ions between 0.7 g / l and 4.4 g / l.

However, it is noted that other sources of divalent ions can be used, such as magnesium, barium, etc. With such a bath, the duration of presence of the beads in the spherification bath is between 30 seconds and 3 minutes. minutes, and preferably between 2 and 2.5 minutes.

A process according to the invention makes it possible to obtain various and varied cosmetic beads, including one or more cosmetic active agents belonging to the following group: vegetable oil; - Essential oil ; - water soluble active; - fat-soluble active; - perfume; - flower water ; - dye.

As already mentioned above, for formulations incorporating a fatty phase, the formulation of the beads preferably comprises at least two distinct viscosity polymers. Ball formulations with exclusively natural components may for example comprise: - for an "anti-wrinkle" treatment: vegetable oils of camelina, flax and hemp, immortal flower essential oil and lemongrass; - for a "first wrinkles" treatment: vegetable rosehip rose oil and mandarin essential oil; - for a "sensitive skin" treatment: rose floral water, rose geranium essential oil and rosewood; 2 996 76 8 16 - for a "stain-resistant" treatment: vegetable oils, bearberry macerate, vanilla macerate. Furthermore, cosmetic beads according to the invention can be packaged in a container closed by a cap including a small spoon. An exemplary embodiment of such a container is illustrated in FIG. 4. As shown in this figure, the balls B are stored in a dome-shaped container 5, which container is covered with a cap 50 rising above the container so as to delimit an internal volume V overlying the balls. The upper part of the cap is separable from the base of the cap, this upper part forming the handle 51 of a small spoon 52 which extends the handle 51 by extending within the volume V. Of course, the spoon 52 15 s extends to such a height that it does not touch the balls when the cap, including the spoon, is present on the container. With such a container, the user can for example proceed in the following manner to carry out a cosmetic treatment: - he separates the cap from the container; 20 - he separates the spoon by removing it from the cap; - he introduces the teaspoon into the container so that a ball takes place in the teaspoon, then withdraws it from the container. Then, he or she can successively: - apply the ball to the skin; - press the ball against the skin until crushing the ball; - massage the skin with the ball crushed until complete penetration. After a few seconds of massage, all the material of the ball 30 has penetrated the skin, and no residue remains on the surface of the skin.

Claims (13)

REVENDICATIONS1. A method for obtaining cosmetic beads, of the type comprising the steps of: - preparing a basic solution incorporating at least one polymer capable of forming a structure according to the "egg box" model; - incorporate in the base solution at least one cosmetic active; preparing a spherification bath with a divalent ion source component; performing a spherification phase of the basic solution incorporating said cosmetic active agent (s); characterized in that: - the step of preparing the basic solution is carried out with at least one polymer present in the solution with a mass concentration greater than or equal to 5g / l; the spherification phase comprises a step of preparing a spherification bath made with a component present with a mass concentration greater than or equal to 0.7 g / l in divalent ions, said component being intended to react with said polymer of the solution basic. 2. Process for obtaining cosmetic beads according to claim 1, characterized in that it comprises an intermediate step of forming the beads of dropping the basic solution incorporating said cosmetic active agent (s) in a bath. cryogenic. 3. Process for obtaining cosmetic beads according to claim 1, characterized in that the duration of presence of the beads in the spherification bath is between 30 seconds and 3 minutes. 4. Process for obtaining cosmetic beads according to claim 1, characterized in that the step of preparing the spherification bath is carried out with a source of calcium. 5. Process for obtaining cosmetic beads according to claim 1, characterized in that the step of preparing the spherification bath is carried out with calcium lactate in a mass concentration of calcium ions between 0.7 g I and 4.4 g / I. 6. Process for obtaining cosmetic beads according to claim 1, characterized in that the step of preparing a base solution is carried out with at least one polymer capable of forming a structure according to the "egg box" model belonging to the next group: - alginates; - carrageenans; - pectins; - gellan. 7. Process for obtaining cosmetic beads according to claim 1, characterized in that it comprises a step of adding a second polymer in the base solution. 8. Process for obtaining cosmetic beads according to claim 7, characterized in that it comprises a step of adding a second polymer, said second polymer being viscose, xanthan type, and having no physical interaction or chemical with the polymer capable of forming a structure according to the model "egg box". 9. Process for obtaining cosmetic beads according to claim 1, characterized in that it comprises a step of adding at least one active agent belonging to the following group: vegetable oil; - Essential oil ; 10 - water soluble active; - fat-soluble active; - perfume; - flower water ; - dye. Cosmetic ball obtained with a process according to any one of claims 1 to 9, characterized in that it comprises at least one cosmetic active belonging to the following group: vegetable oil; Essential oil ; water soluble active; liposoluble active; perfume; 25 floral water; dye. 11. Cosmetic ball according to claim 10, characterized in that it comprises at least two distinct viscosity polymers. 30 12.Bille cosmetics according to one of claims 10 and 11, characterized in that they are packaged in a container (5) closed by a cap (50) including a small spoon (52). 13.Utilization ball according to claim 10, characterized in that it consists of, successively: - apply the ball on the skin; - press the ball against the skin until crushing the ball; - massage the skin with the ball crushed until complete penetration.