Method for forming a dispersion comprising droplets and related device

Abstract

The present invention relates to a method of forming a dispersion (10) comprising droplets (12) having a fatty phase (14) dispersed in a gelled continuous aqueous phase (22), the method comprising the steps of: (i) providing a fatty phase (14) comprising at least one oil and optionally at least one preferably heat-sensitive lipophilic gelling agent; (ii) providing an aqueous phase (16) substantially immiscible with the fatty phase (14), said aqueous phase (16) comprising at least water and at least one hydrophilic gelling agent capable of gelling in the presence of at least one salt; (iii) forming fat phase droplets (14) in the aqueous phase (16) or the gelled continuous aqueous phase (22); (iv) conveying the droplet (12) in the circulation tube (38); (v) recovering the dispersion (10) comprising the droplets (12) and the gelled continuous aqueous phase (22) in a container (33); characterized in that the method comprises at least one of the following steps (vi): (vi1) before step (iii), adding at least a portion of the aqueous solution (62) to the aqueous phase (16); and / or (vi2) injecting at least a portion of an aqueous solution (62) comprising at least one salt capable of reacting with a hydrophilic gelling agent into the circulation tube (38) or at the outlet of the circulation tube (38) upstream of the container (33), the dispersion being free of carbomer and optionally free of ammonia-terminated polydimethylsiloxane.

Description

[0001] The present invention relates to a process for forming a stable oil-in-water dispersion comprising a gelled continuous aqueous phase and dispersed fat phase droplets, in particular droplets visible to the naked eye, wherein the gelled continuous aqueous phase comprises at least one hydrophilic gelling agent which readily gels in the presence of at least one salt.

[0002] To date, there are stable dispersions of droplets of a fat phase, in particular droplets visible to the naked eye, dispersed in a continuous aqueous phase, which are obtained by microfluidic methods, described in particular in WO2017046305.

[0003] This microfluidic approach is particularly effective for forming stable dispersions comprising droplets of perfectly controlled size and exhibiting desirable properties in terms of clarity, texture, viscosity and suspensibility of the fat phase droplets dispersed in the continuous aqueous phase.

[0004] This microfluidic approach is particularly sensitive and many parameters can modify its robustness and / or the kinetic stability of the dispersions obtained. More specifically, the aqueous phase must be sufficiently fluid and homogeneous during the emulsification step and, once the dispersion is formed, sufficiently viscous to produce a suspension of droplets in the continuous aqueous phase.

[0005] The implementation and robustness of the microfluidic method and the satisfactory properties mentioned above depend in particular on the presence of a pH-dependent gelling agent in the continuous aqueous phase, such as a carbomer (or acrylic polymer), such as the carbomer sold under the name of Carbopol by the company Lubrizol. After the formation of the dispersion, the gelling / suspending effect of the carbomer is activated by adding a sodium hydroxide solution to "neutralize" the aqueous phase. Thus, before the formation of the dispersion, the aqueous phase has an acidic pH, i.e. a pH between 3.5 and 5.5, preferably between 4 and 5, to ensure a fluidity compatible with the microfluidic method. After the formation of the dispersion, the gelling of the aqueous phase is carried out by a step of injecting a sodium hydroxide solution. This method is described in the application WO2015055748.

[0006] However, carbomers are synthetic hydrophilic polymers of acrylic acid and are therefore derived from petrochemicals. Their use in cosmetics is increasingly controversial. In addition, the European Chemicals Agency (ECHA) is working with the REACH Committee on a ban on microplastics in cosmetics, which contain carbomers.

[0007] In view of the above, the presence of carbomers is now essential to guarantee stable dispersions, especially those visible to the naked eye, made by microfluidics. Therefore, the replacement of carbomers becomes an important and critical issue, especially when the consumer perception of carbomers suddenly changes, customers include the raw material in their blacklist, or even applicable regulations prohibit its use in cosmetics.

[0008] In addition, carbomers can also participate in the formation of the shell by interfacial complexation and coacervation reactions with lipophilic cationic polymers present in the fat phase, in particular amodimethicone. The fine and residue-free shell after application makes it possible to obtain macroscopic dispersions with better mechanical resistance by microfluidic methods.

[0009] Many attempts to replace carbomer with natural hydrophilic gelling agents have been envisaged. However, such replacement is difficult because the performance of natural hydrophilic gelling agents is relatively low, especially in terms of clarity and non-stickiness.

[0010] Although many natural hydrophilic gelling agents are temperature sensitive, few natural hydrophilic gelling agents like carbomer possess the property of upwardly regulating their viscosity according to physicochemical parameters at room temperature.

[0011] Furthermore, once a gelled aqueous phase with a certain viscosity is sought to be obtained, gels based on natural hydrophilic gelling agents, especially those that are easily gelled in the presence of at least one salt, are generally firm and brittle, whereas carbomer-based gels are flexible, fluid and slightly cohesive. "Slightly cohesive" means that there is an adjusted compromise between the ability of the gel to adhere to itself, unlike brittle gels, without exacerbating the properties too much, otherwise one would encounter gels with a texture / performance such as "egg white", which is undesirable.

[0012] Therefore, there is a need for new dispersions comprising small droplets of a fatty phase dispersed in a continuous aqueous phase, in particular small droplets of a fatty phase having a size visible to the naked eye, and which are still satisfactory in terms of kinetic stability, clarity, texture, feel and comfort upon application, even in the absence of an amodimethicone or a shell.

[0013] There is also a need for new gelled aqueous phase formulations that are variable in viscosity, are carbomer free, and are flexible, flowable, and slightly cohesive upon activation even at high viscosities.

[0014] It is therefore an object of the present invention to provide a simple microfluidic manufacturing method for producing dispersions containing droplets of a fat phase, especially macroscopic droplets, stably suspended in a continuous aqueous phase, providing a non-petrochemical and non-microplastic alternative to Carbomer.

[0015] The subject of the present invention is therefore a method for forming (or manufacturing) a dispersion (10) comprising droplets (12) of a fatty phase (14), said droplets being dispersed in a gelled continuous aqueous phase (22), the method comprising the following steps:

[0016] (i) providing a fatty phase (14) comprising at least one oil and optionally at least one lipophilic gelling agent which is preferably thermosensitive;

[0017] (ii) providing an aqueous phase (16) which is substantially immiscible with the fatty phase (14), said aqueous phase (16) comprising at least water and at least one hydrophilic gelling agent capable of gelling in the presence of at least one salt;

[0018] (iii) forming fat phase droplets (14) in the aqueous phase (16) or the gelled continuous aqueous phase (22);

[0019] (iv) causing the liquid droplets (12) to flow in a circulation pipe (38);

[0020] (v) recovering the dispersion (10) comprising the droplets (12) and the gelled continuous aqueous phase (22) in a container (33);

[0021] Characterized in that the method comprises at least one of the following steps (vi):

[0022] (vi1) before step (iii), adding at least a portion of the aqueous solution (62) to the aqueous phase (16); and / or

[0023] (vi2) injecting at least a portion of the aqueous solution (62) into the circulation pipe (38) or at the outlet of the circulation pipe (38) upstream of the container (33),

[0024] The aqueous solution (62) comprises at least one salt capable of reacting with the hydrophilic gelling agent.

[0025] In view of the above, the aqueous phase (16) advantageously does not contain carbomer.

[0026] Likewise, there is an increasing demand among consumers for cosmetic compositions that do not contain silicone compounds, which have an impact on the environment because they are non-biodegradable, and / or because they may present health risks.

[0027] Therefore, the dispersion according to the invention, and more particularly the fatty phase ( 14 ), is advantageously free of amodimethicone.

[0028] When step (vi1) fully or partially represents step (vi), the method according to the invention may be designated indifferently by "first method" in the rest of the description.

[0029] When step (vi2) fully or partially represents step (vi), the method according to the invention may be referred to indifferently as the "second method" hereinafter in the description.

[0030] In the remainder of the description, the solution comprising at least one salt may be referred to indiscriminately by the expressions “solution ( 62 )”, “aqueous solution ( 62 )”, “additional solution” or “BF”.

[0031] As shown in the examples, the advantage of the microfluidic method according to the invention is that it is used to produce in a continuous, simple and robust manner stable dispersions, whether single or multiple, comprising droplets of a fat phase, of a controllable and even macroscopic size and having satisfactory optical properties, without the need to use any carbomer.

[0032] The method according to the invention is also advantageous in that it is based on a microfluidic alternative:

[0033] —No microplastics;

[0034] - adjustable or "scalable" viscosity of the continuous aqueous phase via a pair of raw materials of natural origin;

[0035] — compatible with temperatures up to 50°C; and

[0036] - Easy to make the continuous phase have satisfactory properties in terms of clarity, texture and sensory experience.

[0037] An adjustable or "scalable" viscosity is one that is compatible with the constraints of the microfluidic process until a dispersion is formed under normal conditions and can then be increased to produce a satisfactory suspension of fat phase droplets in a continuous aqueous phase.

[0038] Likewise, the advantage of this alternative is that it makes it possible to obtain a dispersion comprising a continuous aqueous phase having particularly satisfactory properties in terms of kinetic stability, more particularly the ability to suspend the droplets, viscosity and comfort during application (more particularly duration of action). However, this standard combination is an unnoticeable compromise, especially considering the absence of carbomer or shell.

[0039] Furthermore, the present invention makes it possible to obtain dispersions, in particular cosmetic dispersions, comprising at least one fluid gelled aqueous phase (22) comprising at least one salt and at least one hydrophilic gelling agent which readily gels in the presence of one or more salts, the dispersion being free of carbomer and optionally free of amodimethicone.

[0040] "Fluid" as defined in the present invention refers to a gelled aqueous phase that retains its ability to flow under its own weight at ambient temperature and atmospheric pressure. More particularly, the gelled aqueous phase according to the present invention retains the ability to conform to the shape of its container. In other words, the gelled aqueous phase according to the present invention is not in the form of a solid mass, in particular not in the form of a hard, brittle solid gel.

[0041] Contrary to all expectations, the inventors have observed that the present invention makes it possible to obtain fluid (or liquid) gels having properties similar to those observed for carbomer gels, in particular in terms of clarity and non-stickiness.

[0042] Furthermore, the invention makes it possible to obtain suspended liquid gels for the manufacture of dispersions.Thus, surprisingly, the gelled aqueous phase (22) according to the invention remains compatible with microfluidic processes at ambient temperature, without affecting the above-mentioned advantages in terms of transparency and non-stickiness.

[0043] The method according to the invention may comprise one or more of the following features, taken alone or in any technically possible combination:

[0044] - the fat phase droplets and the aqueous phase flow in the circulation pipe along the local axis, the injection of the additional aqueous solution (62) being carried out substantially parallel to the local axis (or even coaxially);

[0045] - injection of additional aqueous solution (62) includes bringing at least a portion of the solution to the center of the flow of droplets and aqueous phase;

[0046] - injection of additional aqueous solution (62) includes bringing at least a portion of the solution to the periphery of the flow of droplets and aqueous phase;

[0047] The method comprises reducing the cross-section of the flow of droplets and aqueous phase downstream of the injection of the aqueous solution (62);

[0048] - the injection of the aqueous solution (62) is carried out at the outlet of the circulation pipe (38);

[0049] - upstream of process step (iv) (or circulation), the method comprises a step of forming droplets (12) in a circulation pipe (38);

[0050] —Injection of the aqueous solution (62) includes bringing at least a portion of the solution (62) into a solution distribution ring (210) located in the center of the circulation tube (38), and the droplets (12) flow through a central channel (212) defined by the ring (210) and through a peripheral channel (214) defined between the ring and the circulation tube (38).

[0051] - according to step (vi2), a first sub-step 100 of injecting a first aqueous solution (62) suitable for increasing the viscosity of the aqueous phase (16), thereby obtaining an intermediate dispersion 102 comprising a continuous aqueous phase 22 of partially increased viscosity,

[0052] After the recovery step (v), the method further comprises at least a second sub-step 104, comprising:

[0053] ■ recirculating the intermediate dispersion 102; and

[0054] ■ Inject the second aqueous solution (62) into the intermediate dispersion 102.

[0055] - A recycling step consists in circulating the intermediate dispersion 102 in the additional line 106 and then recovering the final dispersion 10 according to the invention in a container at the outlet of the additional line 106, the injection of the second aqueous solution (62) being carried out in the additional line 106 or at the outlet of the additional line 106 upstream of the container 33. This embodiment Figure 8 Specifically shown in.

[0056] Another subject of the invention is a device for forming a dispersion 10 containing droplets 12, comprising:

[0057] a circulation pipe (38) containing droplets (12) of the fat phase (14) in an aqueous phase (16) which is substantially immiscible with the fat phase (14);

[0058] a container (33) for recovering the dispersion (10) containing the droplets (12) and the aqueous phase (16);

[0059] Characterized in that the device (30) comprises:

[0060] a tank (68) containing an aqueous solution (62) comprising at least one salt;

[0061] at least one injection line (60) connected to the tank (68) for injecting the aqueous solution (62) and entering the circulation pipe (38) or at the outlet of the circulation pipe (38) upstream of the container (33),

[0062] The fatty phase (14) comprises at least one oil and optionally at least one lipophilic gelling agent which is preferably thermosensitive; and

[0063] The aqueous phase (16), which is substantially immiscible with the fatty phase (14), comprises at least water and at least one hydrophilic gelling agent susceptible to gelling in the presence of at least one salt.

[0064] In view of the above, the aqueous phase (16) is advantageously free of carbomer and, optionally, the fatty phase (14) is advantageously free of amodimethicone.

[0065] The device according to the invention may comprise one or more of the following features, taken alone or in any technically possible combination:

[0066] - The circulation tube extends along the local axis of the circulation of the droplets and the second phase, and the injection line projects coaxially with the local axis;

[0067] - The device comprises a peripheral injection line and / or a central injection line, the peripheral injection line for injecting at least a portion of the additional solution, projecting from the periphery of the circulation tube, and the central injection line for injecting at least a portion of the additional solution, projecting from the center of the circulation tube;

[0068] - The device comprises a unit for forming droplets in the circulation tube, and the unit for forming droplets advantageously comprises:

[0069] ■ A line for supplying a first fluid (36) which comprises a fatty phase (14) and optionally at least one preferably thermosensitive gelling agent comprised in the fatty phase (14);

[0070] ■ A line for forming droplets of the first fluid (36) in a second fluid (40) which is intended to form an aqueous phase (16), the second fluid (40) comprising at least water and at least one hydrophilic gelling agent which is prone to gelling in the presence of at least one salt.

[0071] Another subject of the invention relates to a dispersion comprising droplets (12) of a fatty phase (14) dispersed in a gelled continuous aqueous phase (22), wherein:

[0072] - Droplets (12) having a diameter greater than or equal to 100 μm represent a volume of more than or equal to 60%, or even more than or equal to 70%, preferably more than or equal to 80% and more preferably more than or equal to 90% of the total volume of the dispersed phase and / or the average diameter of at least 60%, even at least 70%, preferably at least 80% and more preferably at least 90% of the droplets is greater than or equal to 100 μm;

[0073] - The fatty phase comprises at least one oil and optionally at least one preferably thermosensitive lipophilic gelling agent; and

[0074] - The gelled continuous aqueous phase comprises at least water, at least one hydrophilic gelling agent gelled by at least one salt,

[0075] The dispersion is free of carbomer and optionally free of amino-terminated polydimethylsiloxane.

[0076] The dispersion according to the invention has the advantage of being stable (or "kinetically stable"), in particular over time and during transport. "Stable" as defined in the present invention means in particular that there is no foaming or precipitation of the droplets of the phase dispersed in the continuous phase, no turbidity of the continuous phase, no aggregation of the droplets with each other, in particular no coalescence or Ostwald ripening between the droplets, and no leakage of material from the dispersed phase to the continuous phase or vice versa.

[0077] In the context of the present invention, the above-mentioned dispersions may be denoted indifferently by the term "dispersion".

[0078] According to another embodiment, the dispersion according to the invention does not comprise any surfactants.

[0079] Preferably, the pH value of the dispersion according to the invention is between 3.0 and 6.5, preferably between 4.0 and 6.0, better still between 5.0 and 6.0.

[0080] Unless otherwise stated, in the following, temperature is considered to be ambient temperature (e.g., T = 25°C ± 2°C), and pressure is considered to be atmospheric pressure (760 mm Hg, or 1013 x 10 5 Pa or 10 13 mbar).

[0081] The invention will be better understood upon reading the following description which is given by way of example only and with reference to the accompanying drawings, in which:

[0082] — Figure 1 is a side view of a container containing a monodispersion obtained by a second method according to the present invention;

[0083] — Figure 2 is a cross-sectional view of a droplet of a monodispersion according to the present invention;

[0084] — Figure 3 is a schematic partial cross-sectional view of a first apparatus for producing a monodispersion for implementing the second method;

[0085] — Figure 4 is a cross-sectional view of a droplet of a multidispersion according to the present invention;

[0086] — Figure 5 is a schematic partial cross-sectional view of a first apparatus for producing a multiple dispersion for implementing the second method;

[0087] — Figure 6 is a detailed view of the end of the circulation pipe of a variant of the device according to the invention, in which the injection of the additional solution (62) is carried out at the end of the circulation pipe;

[0088] — Figure 7 yes Figure 6a top view of the end portion presented in FIG. 1 ; and

[0089] — Figure 8 is with Figure 5 A similar view of a variant of a device for producing a multidispersion for carrying out the second method according to the invention.

[0090] Figures 1 to 3 The realization of the second method for forming a monodispersion according to the invention is shown.

[0091] Figure 4 and Figure 5 The implementation of the second method for forming a multidispersion according to the invention is shown.

[0092] Immiscible

[0093] The fat phase 14 (or dispersed phase) and the aqueous phase 16 (or continuous phase) are substantially immiscible.

[0094] "Substantially immiscible" as defined in the present invention means that the solubility of the first phase in the second phase is advantageously less than 5% by weight.

[0095] According to a first variant embodiment, the dispersion according to the invention may be a simple emulsion, more particularly an oil-in-water direct emulsion.

[0096] According to a second embodiment variant, the dispersion according to the invention may be a multiple emulsion, thus using a third phase 19 (or inner dispersed phase), in which case the fatty phase 14 (or intermediate dispersed phase) is located between the third phase 19 and the aqueous phase 16 (or continuous phase), as Figure 4 As shown. Therefore, the fat phase 14 is substantially immiscible with the third phase 19, and the fat phase 14 is substantially immiscible with the water phase 16. More specifically, the multiple dispersion according to the present invention is, for example:

[0097] — a water-in-oil-in-water dispersion, or

[0098] - Oil-in-oil-in-water dispersions, in which case the third oily phase 19 and the oily fatty phase 14 comprise substantially immiscible oils.

[0099] "Substantially immiscible oils" or "immiscible oils" as defined herein means that a mixture of two oils does not produce a homogeneous single-phase solution. A person skilled in the art will be able to adjust the choice of oil to meet the above "immiscible" criterion. Oils that are immiscible with each other are particularly described in FR1752204.

[0100] According to a variant, the method according to the invention aims at forming a single final dispersion based on a transient formation step of a multiple dispersion.Thus, in a transient multiple emulsion, the third phase 19 is oily and miscible with the fatty phase 14 .

[0101] Continuous water phase

[0102] The dispersion according to the invention comprises a continuous aqueous phase.

[0103] The aqueous phase according to the invention comprises water. Besides distilled water or deionized water, water suitable for the invention may also be natural mineral water or floral water.

[0104] According to one embodiment, the mass percentage of water in the aqueous phase relative to the total weight of the continuous aqueous phase is at least 30%, preferably at least 40%, more particularly at least 50%, better still at least 60%, in particular between 70% and 98%, preferentially between 75% and 95%.

[0105] Preferably, the continuous aqueous phase of the dispersion according to the invention does not comprise any base, more particularly does not comprise NaOH.

[0106] Preferably, the continuous aqueous phase of the dispersion according to the invention does not comprise any carbomer (or acrylic polymer).

[0107] A hydrophilic gelling agent that readily gels in the presence of at least one salt

[0108] "Hydrophilic" means that the gelling agent is soluble or dispersible in water.

[0109] A hydrophilic gelling agent that readily gels in the presence of at least one salt, also known as an "ion-sensitive hydrophilic gelling agent", is an agent that can, in particular, in the presence of at least one salt, adjust the fluidity of the aqueous phase containing the gelling agent, and thus the texture and / or the feel of the dispersion. When the composition further comprises a dispersed fatty phase, a hydrophilic gelling agent that readily gels in the presence of at least one salt is an agent that can also suspend said droplets in the continuous aqueous phase.

[0110] The hydrophilic gelling agent which readily gels in the presence of at least one salt may also provide, completely or partially, the suspending properties of the continuous aqueous phase relative to the fatty phase droplets and thus completely or partially the kinetic stability of the dispersion, in particular by completely or partially preventing / limiting the phenomena of coalescence and / or emulsification and / or precipitation of the droplets with one another in the continuous aqueous phase.

[0111] For obvious reasons, the choice of the hydrophilic gelling agent or agents susceptible to gelling in the presence of at least one salt should be adapted to the composition of the additional solution comprising at least one salt.

[0112] Such adaptation is within the ordinary skill of those skilled in the art.

[0113] Preferably, the hydrophilic gelling agent that is prone to gelation in the presence of at least one salt is a polyelectrolyte that reacts to at least one salt, more particularly in the presence of at least one monovalent or divalent ion (such as K + , Na + , Ca ++ or Mg ++ ).

[0114] The hydrophilic gelling agent that is prone to gelation in the presence of at least one salt can be selected from natural polymers, biopolymer, modified polymers, and mixtures thereof, preferably selected from natural polymers.

[0115] Preferably, the hydrophilic gelling agent that is prone to gelation in the presence of at least one salt is selected from polysaccharides based on one of alginate, alginate, pectin, carrageenan, gellan gum, Diutan gum, furcellaran or derivatives thereof, and mixtures thereof, more particularly selected from gellan gum and / or carrageenan, most particularly selected from gellan gum and / or ι-carrageenan.

[0116] Preferably, the hydrophilic gelling agent that is prone to gelation in the presence of at least one salt can be selected from carrageenan, more particularly κ-carrageenan and ι-carrageenan; gellan gum, especially low acyl gellan gum; alginate; pectin, especially low methoxyl pectin; Diutan gum; furcellaran; or one of their derivatives; and mixtures thereof.

[0117] As carrageenan, reference products sold by Cargill Beauty under the name Satiagel VPC 508P (INCI: ι-carrageenan (and) carrageenan extract) can be mentioned.

[0118] As gellan gum, reference products sold by CP Kelco under the name Kelcogel CG LA or Kelcogel CG-LA[E] (INCI: gellan gum) can be mentioned.

[0119] As alginate, reference products sold by Algaia under the name Algogel VCG 1561 or by Alchemyingredients under the name Sclerothix (INCI: xanthan gum (and) scleroglucan (and) alginate) can be mentioned.

[0120] Advantageously, the hydrophilic gelling agent that is prone to gelation in the presence of at least one salt is not selected from alginate or alginate.

[0121] Preferably, the hydrophilic gelling agent that is prone to gelation in the presence of at least one salt is not a thermosensitive hydrophilic gelling agent.

[0122] By "thermosensitive hydrophilic gelling agent" is meant a gelling agent that reacts with heat, in particular a gelling agent that is solid at ambient temperature and liquid at temperatures above 40°C, preferably above 50°C.

[0123] The dispersion according to the invention may contain from 0.01% to 5%, preferably from 0.05% to 2.5%, better still from 0.05% to 1% and most particularly from 0.08% to 0.5% of hydrophilic gelling agent(s) to be gelled in the presence of at least one salt relative to the total weight of the aqueous phase (16).

[0124] Preferably, the hydrophilic gelling agent present in the gelling aqueous phase according to the invention is of natural origin and is preferably biodegradable.

[0125] Preferably, the gelled aqueous phase (22) or even the dispersion according to the invention is natural and preferably biodegradable.

[0126] "Natural" as defined in the present invention means that the composition comprises a proportion of ingredients of natural origin greater than or equal to 95%, preferably greater than or equal to 96%, more particularly greater than or equal to 97%, better still greater than or equal to 98%, according to ISO standard 16128. The method of calculating the proportions is described in FR3119317.

[0127] Given the manufacturing method according to the present invention:

[0128] - the continuous aqueous phase (16) is in a liquid state at ambient temperature and atmospheric pressure. In other words, the continuous phase (16) is not a solid at ambient temperature and atmospheric pressure;

[0129] The viscosity of the gelled continuous aqueous phase (22) of the dispersion obtained after mixing the continuous aqueous phase (16) with the aqueous solution (62) is necessarily higher than the viscosity of the continuous aqueous phase (16) and is preferably in a gel state.

[0130] Advantageously, the gelled continuous aqueous phase (22) has a flow threshold suitable for providing suspension (or suspendability) of the droplets for a period of time greater than or equal to 1 month, preferably greater than or equal to 3 months, better still greater than or equal to 6 months and most particularly greater than or equal to 12 months. In addition to the associated visual aspects, the suspension properties also serve to improve the dynamic stability of the dispersion, in particular preventing / limiting the phenomena of mutual coalescence and / or emulsification and / or precipitation of the droplets in the continuous phase, thus further preventing any changes in the visual appearance of the dispersion according to the invention.

[0131] More particularly, the aqueous phase (16) therefore has a viscosity measured at 25°C of between 1 and 10000 mPa.s, preferably from 10 to 8000 mPa.s, particularly from 100 to 5000 mPa.s, more particularly from 200 to 2500 mPa.s, before mixing with the solution (62).

[0132] More particularly, the gelled continuous aqueous phase (22) of the dispersion according to the invention has a viscosity, measured at 25° C., of between 1000 MPa.s and 50000 MPa.s, preferably between 2000 MPa.s and 40000 MPa.s, in particular between 3000 MPa.s and 30000 MPa.s, more particularly between 3500 MPa.s and 20000 MPa.s, most particularly between 4000 MPa.s and 10000 MPa.s, after mixing the aqueous phase (16) with the aqueous solution (62).

[0133] The viscosity was measured at ambient temperature and pressure by the method described in WO2017046305.

[0134] The aqueous phase (22) is a non-Newtonian fluid. The same is true for rheological fluids.

[0135] Preferably, the gelled aqueous phase (22) of the dispersion according to the invention is transparent or at least translucent. The transparency or translucency property is determined according to the protocol described in the examples below.

[0136] The gelled aqueous phase (22) of the dispersion according to the invention is also advantageous because it has unexpected properties in terms of shear elasticity, also known as "viscosity regeneration time" or "reconstitution time", i.e. the time necessary for a sample to recover a viscosity at least equal to 75% of the original viscosity.

[0137] Method for measuring regeneration percentage:

[0138] All measurements were performed using a Ta Instrument DHR10 rheometer equipped with a 40 mm diameter translation stage forming a 1° cone and an air gap of 29 μm. The measurements were performed at 18 °C and the temperature was controlled by a Peltier device.

[0139] The thixotropic behavior was measured using the 3ITT (3 Interval Thixotropy Test) test protocol. This protocol consists of subjecting the sample to 3 different shear steps in succession, namely:

[0140] First step (=reference interval): 0.1s for the sample -1 The viscosity at rest is evaluated by low shearing for 30 seconds and measuring each point for 1 second; the measurement results will be used as a reference for the test.

[0141] Second step (= high shear interval): subject the sample to 300 s -1 The high shear was applied for 30 seconds, which will break the structure of the sample, and each point was measured for 1 second.

[0142] Step 3 (= regeneration interval): perform initial shearing on the sample, i.e. 0.1s -1 The shearing time was 300 seconds and each point was measured for 1 second.

[0143] The time required for the sample to recover a viscosity of at least 75% of the original viscosity is referred to as the "reconstitution time".

[0144] Thus, according to the above method, after the third regeneration interval of 30 seconds, the aqueous phase (22) according to the invention advantageously has a regeneration percentage of its viscosity of at least 75%, preferably at least 80%, more particularly at least 85% or even at least 90%.

[0145] Therefore, the aqueous phase (22) according to the present invention can be considered to be elastic to shear.

[0146] More particularly, the gelled continuous aqueous phase (22) of the dispersion according to the invention has a flow threshold greater than 0.1 Pa, more particularly greater than 1 Pa, preferably between 0.5 Pa and 100 Pa, more particularly between 1 Pa and 75 Pa, most particularly between 2 Pa and 50 Pa, or even between 5 Pa and 25 Pa, better still between 10 Pa and 20 Pa.

[0147] The flow threshold is measured at ambient temperature and pressure using a flow shear rate sweep method as described in A Handbook of Elementary Rheology by HA Barnes (Institute of Non-Newtonian Fluid Mechanics, University of Wales, 2000) or at http: / / www.tainstruments.com / pdf / literature / RH025.pdf.

[0148] Furthermore, the continuous gelled aqueous phase (22) of the dispersion according to the invention has a pleasant sensory feel, in particular a "break in water" type of feeling, i.e. a feeling of freshness and hydration felt when the hydrogel breaks under applied pressure and releases the water it contains.

[0149] This sensation is unexpected since it is usually not achievable or only slightly achievable with the hydrophilic gelling agents according to the invention which readily gel in the presence of at least one salt.

[0150] This sensation was all the more unexpected because of the desirable properties in terms of action time and non-stickiness.

[0151] Thus, when applying the method according to the invention to keratin materials, dispersions can be obtained having an average action time of less than 3 minutes, preferably less than 2 minutes, more preferably less than 1 minute.

[0152] Dispersed fat phase

[0153] The dispersion according to the invention may comprise from 1% to 60%, more particularly from 5% to 50%, preferably from 10% to 40% and better still from 15% to 30% of fatty phase (14) by weight relative to the total weight of the dispersion (10).

[0154] Preferably, the fatty phase of the dispersion according to the invention does not contain any lipophilic cationic polymers, more particularly does not contain amodimethicone (or aminosilicone).

[0155] The fatty phase (or oil phase) according to the invention comprises at least one oil and optionally at least one lipophilic gelling agent.

[0156] Oil

[0157] "Oil" refers to fats that are liquid at ambient temperature.

[0158] As oils which can be used in the dispersions according to the invention, mention may be made, for example, of:

[0159] - hydrocarbon oils of vegetable origin, such as hydrogenated jojoba oil, hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated coconut oil;

[0160] - hydrocarbon oils of animal origin, such as perhydrosqualene and squalane;

[0161] - synthetic esters and ethers, especially those of fatty acids, for example oils of the formula R1COOR2 and R1OR2, in which R1 represents C 8 To C 29 Fatty acid residue, R2 represents C 3 To C 30Hydrocarbon chains, whether branched or unbranched, such as Purcellin oil, isononyl isononanoate, isodecyl neopentanoate, isostearate neopentanoate, isopropyl myristate, ethyl-2-hexyl palmitate, octyl-2-dodecyl stearate, octyl-2-dodecyl erucate, isostearate isostearate; hydroxy esters, such as isostearate lactate, octyl hydroxystearate, octyl dodecyl hydroxystearate, diisostearate malate, triisohexadecyl citrate, heptanoate, octanoate, decanoate of fatty alcohols; polyol esters, such as propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; and pentaerythritol esters, such as pentaerythritol tetrabehenate (DUB PTB) or pentaerythritol tetraisostearate (Prisorine 3631);

[0162] - straight-chain or branched hydrocarbons of mineral or synthetic origin, such as volatile or non-volatile paraffin oils and their derivatives, petrolatum, polydecenes, hydrogenated polyisobutenes, such as Parleam oil;

[0163] - silicone oils, such as volatile or non-volatile polymethylsiloxanes (PDMS) with a linear or cyclic silicon chain, liquid or pasty at room temperature, in particular cyclopolydimethylsiloxanes (cyclomethicones), such as cyclohexasiloxane and cyclopentasiloxane; polydimethylsiloxanes (or dimethicones) containing alkyl, alkoxy or phenyl groups during or at the ends of the silicon chain, containing groups of 2 to 24 carbon atoms; phenylsilicones, such as phenyl trimethicone, phenyl dimethicone, phenyl trimethylsiloxydiphenylsiloxane, diphenyl dimethicone and diphenylmethyl diphenyl trisiloxane, 2-phenylethyl trimethylsiloxysilicate and polymethylphenylsiloxane;

[0164] - fatty alcohols having 8 to 26 carbon atoms, such as cetyl alcohol, stearyl alcohol and mixtures thereof (cetostearyl alcohol), or octyldodecanol;

[0165] - partially hydrocarbon-based and / or silicon-based fluorinated oils as described in JP-A-2-295912;

[0166] —and mixtures thereof.

[0167] In a preferred embodiment, the oil is selected from the group consisting of isononyl isononanoate, dimethicone, isohexadecane, dimethicone, octyldodecanol, isodecyl neopentanoate, and mixtures thereof.

[0168] According to another preferred embodiment, the fatty phase does not comprise any silicone oil and preferably does not comprise any polydimethylsiloxane (PDMS).

[0169] A person skilled in the art will be able to adjust the nature and / or content of the oil or oils in order in particular to provide a satisfactory dynamic stability of the dispersion according to the invention and to preserve the aforementioned advantageous technical effects.

[0170] The dispersion according to the invention may comprise from 30% to 100%, more particularly from 40% to 90%, preferably from 50% to 80%, more particularly from 60% to 70% of oil by weight of oil or oils relative to the total weight of the fatty phase.

[0171] Lipophilic gelling agent

[0172] The lipophilic gelling agent, i.e. a gelling agent soluble or dispersible in the fatty phase, may be chosen from organic or inorganic, polymeric or molecular gelling agents; fats that are solid at ambient temperature and pressure, in particular from waxes, pasty fats and butters; and mixtures thereof, preferably being a polymeric gelling agent.

[0173] Such lipophilic gelling agents are particularly described in WO2019002308.

[0174] Among the lipophilic gelling agents that can be used in the present invention, mention may be made of dextrin esters and fatty acid esters, such as dextrin palmitate. Among the dextrin esters and fatty acid esters, mention may be made, for example, of dextrin palmitate, dextrin myristate, dextrin palmitate / ethyl caproate and mixtures thereof. Particular mention may be made of the dextrin esters sold by Miyoshi Europe under the trade name D2 (INCI name: Dextrin Palmitate), TT2 (INCI name: Dextrin Palmitate Ethyl Hexanoate) and Dextrin esters and fatty acid esters sold under the name MKL2 (INCI name: Dextrin myristate), and dextrin palmitate sold by The Innovation Company.

[0175] From Elementis specialties R (INCI: trihydroxystearin), OILKEMIA from Lubrizol TM 5S polymer (INCI: Caprylic / capric triglyceride (and) polyurethane-79), Estogel M from PolymerExpert (INCI: Castor oil / IPDI copolymer and Caprylic / capric triglyceride), hydrogenated castor oil / sebacic acid copolymer and its derivatives, in particular those sold by PolymerExpert under the names Estogel Green (or Estogel G) and Estogel Green 40, respectively, and mixtures thereof.

[0176] Advantageously, the lipophilic gelling agent is a thermosensitive gelling agent.

[0177] Advantageously, the lipophilic gelling agent is a thixotropic gelling agent or a gelling agent that tends to impart thixotropic behavior to the fatty phase. Such a thixotropic gelling agent is chosen in particular from the fumed silicas described above that have been appropriately treated to be hydrophobic.

[0178] According to the invention, the dispersion 10 according to the invention may comprise from 0.5% to 30% of lipophilic gelling agent(s) relative to the total weight of the fatty phase 14, preferably from 1% to 25%, more particularly from 1.5% to 20%, better still from 2% to 15% and most particularly from 5% to 12%.

[0179] Droplets

[0180] The dispersed fatty phase of the dispersion according to the invention is in the form of droplets, preferably macroscopic droplets, ie visible to the naked eye.

[0181] Hereinafter, in this specification, the fat phase droplets may also be referred to as "droplets (G1)".

[0182] Advantageously, the dispersion according to the invention is intended to form a dispersion in which the droplets (G1) with a diameter greater than or equal to 100 μm represent more than or equal to 60%, or even more than or equal to 70%, preferably more than or equal to 80% and better still more than or equal to 90% of the volume of the total volume of the dispersed phase and / or at least 60%, even at least 70%, preferably at least 80% and better still at least 90% of the droplets have an average diameter greater than or equal to 100 μm. Preferably, the diameter is greater than or equal to 150 μm, better still greater than or equal to 200 μm, more particularly greater than or equal to 250 μm, preferably greater than or equal to 300 μm, more particularly greater than or equal to 400 μm, better still greater than or equal to 500 μm.

[0183] Preferably, the droplets (G1) have a diameter greater than or equal to 100 microns, more particularly greater than or equal to 250 microns, preferably greater than or equal to 500 microns, in particular between 250 and 3000 microns, preferably between 500 and 2000 microns, even between 750 and 1500 microns.

[0184] Therefore, in the dispersion according to the invention, its constituent phases form a macroscopically inhomogeneous mixture.

[0185] The droplets are advantageously substantially spherical.

[0186] Advantageously, the droplets are apparently monodisperse (ie, the eye perceives them as spheres of uniform diameter).

[0187] Preferably, the dispersion of the invention consists of a population of monodisperse droplets, in particular such that the average diameter Between 100 μm and 3000 μm, more particularly between 500 μm and 3000 μm, and the coefficient of variation Cv is less than 10%, or even less than 3%.

[0188] In the framework of the present description, "monodisperse droplets" means that the droplet population of the dispersion according to the invention has a uniform size distribution. Monodisperse droplets exhibit good monodispersity. On the other hand, droplets that exhibit poor monodispersity are called "polydisperse".

[0189] According to one embodiment, the average diameter of the droplets is measured, for example, by analyzing a photograph of a batch consisting of N droplets using an image processing software (Image J). Typically, according to this method, the diameter is measured in pixels and then related to μm as a function of the size of the container containing the dispersion droplets.

[0190] Preferably, the value of N is chosen to be greater than or equal to 30, so that this analysis reflects statistically significantly the distribution of the diameters of the droplets of the emulsion. N is advantageously greater than or equal to 100, in particular in the case where the dispersion is polydisperse.

[0191] The diameter Di of each droplet was measured, and the average diameter was obtained by calculating the arithmetic mean of the following values:

[0192]

[0193] According to the value of Di, the standard deviation σ of the diameter of the dispersion droplets can also be obtained:

[0194]

[0195] The standard deviation σ of the dispersion reflects the diameter of the small droplets Di of the dispersion in the average diameter Distribution around.

[0196] By knowing the average diameter of the dispersion And the standard deviation σ, it can be determined that 95.4% of the droplet groups are in the diameter range and 68.2% of the droplet groups are in the interval Inside.

[0197] To characterize the monodispersity of a dispersion according to said embodiment of the invention, the coefficient of variation may be calculated:

[0198]

[0199] This parameter reflects the diameter distribution of the droplets according to their average diameter.

[0200] The coefficient of variation Cv of the diameter of the droplets according to said embodiment of the invention is less than 10%, preferably less than 5%, or even less than 3%.

[0201] Alternatively, monodispersity can be confirmed by placing a sample of the dispersion in a bottle of constant circular cross-section and gently stirring it by rotating the bottle a quarter turn in half a second about an axis of symmetry passing through the bottle, followed by a half-second rest and then repeating the operation in the opposite direction four times in succession.

[0202] When the droplets are monodisperse, the droplets of the dispersed phase are organized in a crystalline form. The droplets are thus stacked in a pattern that repeats in three dimensions. Regular stacking can then be observed, indicating good monodispersity, and irregular stacking reflects the polydispersity of the dispersion.

[0203] This monodisperse nature is a direct consequence of the microfluidic approach according to the invention.

[0204] The droplets may be single-phase or multi-phase. For example, the droplets comprise a core (which comprises at least a fat phase), optionally a shell (or envelope or membrane) completely encapsulating the core, wherein the core itself may comprise one or more phases.

[0205] According to a first embodiment, the droplets according to the invention are solid (or single-phase) particles.

[0206] According to a second embodiment, the droplets according to the invention are core / shell particles. A core / shell droplet is a capsule comprising a core, which is preferably liquid or at least partially gelled or at least partially thixotropic, and a shell, which completely encapsulates the core, which is single-phase and therefore comprises a fat phase.

[0207] Figure 2 A solid pearl droplet is shown.

[0208] According to this variant, the droplets can also be solid or core / shell particles, comprising an intermediate droplet (G1) of an intermediate fat phase and at least one (preferably a single) inner phase (or third phase 19) inner droplet (G2) arranged in the intermediate droplet (G1), the intermediate phase (or fat phase 14) being placed in contact with the aqueous phase 16 or the shell (when present). Figure 4 Such a composite droplet is shown.

[0209] According to this variant, the intermediate fat phase advantageously comprises at least one lipophilic gelling agent, in particular a gelling agent as defined above, in order to improve in particular the suspendability of the droplet or drops (G2) arranged in the intermediate droplet (G1), thereby preventing / avoiding emulsification or precipitation phenomena of the droplet or drops (G2).

[0210] Preferably, the dispersed fat phase is transparent or at least translucent. The transparency or translucency of the dispersed phase is determined as follows: the composition to be tested (30 ml) is poured into a 30 ml volga can, the composition is left at ambient temperature for 24 hours, and a white sheet is placed underneath on which a cross of about 2 mm thickness is drawn with black felt. If the cross is visible to the naked eye in daylight at a viewing distance of 40 cm, the composition is transparent or translucent.

[0211] According to a specific embodiment:

[0212] the continuous aqueous phase of the dispersion according to the invention may itself be in the form of a direct emulsion comprising a dispersed fatty phase in the form of droplets (G3) whose size is preferably smaller than that of the droplets (G1) or even smaller than that of the droplets (G2); and / or

[0213] - the dispersed fat phase or, even in the case of a multiple dispersion (or composite droplets) as defined above, the intermediate fat phase and / or the internal phase, may be in the form of a direct or inverse emulsion comprising droplets (G4) and / or (G5), the size of the droplets (G4) and / or (G5) necessarily being smaller than that of the droplets (G1) or even of the droplets (G2).

[0214] The droplets (G3) and / or (G4) and / or (G5) are preferably microscopic, ie invisible to the naked eye, and in particular have a size of less than 100 μm, preferably less than 20 μm, better still less than 10 μm.

[0215] In other words, droplet (G3) and / or (G4) and / or (G5) are different from and independent of droplet (G1), or even different from and independent of droplet (G2).

[0216] The droplets (G1) of the dispersion according to the invention advantageously do not contain any shell, more particularly any polymeric membrane or membrane formed by interfacial polymerization. More particularly, the droplets (G1) of the dispersion according to the invention are not stabilized by a coacervate such as anionic polymer (carbomer) / cationic polymer (amodimethicone) membrane. In other words, the contact between the continuous aqueous phase and the dispersed fatty phase is preferably direct.

[0217] According to another embodiment, the droplet (G1) comprises a shell.

[0218] The presence of the shell advantageously enhances the dynamic stability of the droplets (G1) and thus of the dispersion.

[0219] An aqueous solution comprising at least one salt

[0220] The aqueous solution comprises at least one salt which acts as a gelling activator for the ion-sensitive hydrophilic gelling agent.

[0221] Of course, the one or more salts are selected from salts that react readily with a hydrophilic gelling agent that readily gels in the presence of at least one salt. In other words, the selection of the one or more salts present should be adjusted relative to the hydrophilic gelling agent that readily gels in the presence of at least one salt.

[0222] “Readily reactive with a gelling agent that readily gels in the presence of at least one salt” refers to a salt that readily adjusts, most particularly readily increases, the viscosity of an aqueous phase comprising a hydrophilic gelling agent that readily gels in the presence of at least said salt.

[0223] The aqueous solution comprising at least one salt (or “additional solution” or “BF” or “solution 62 ”) is miscible with the continuous aqueous phase 16 .

[0224] This additional solution added to the aqueous phase (16) before step (iii) and / or after step (iv) has the effect of interacting with the gelling agent that is susceptible to gelling in the presence of at least one salt, thereby inducing its gelling, thereby increasing the suspendability (i.e. flow threshold) or even the viscosity of the aqueous phase 16, thereby obtaining a continuous gelled aqueous phase (22).

[0225] As described below, the viscosity of the aqueous phase 16 of the dispersion is advantageously increased to keep the droplets 12 suspended, preferably over a period of at least 1 month, preferably at least 3 months, better still at least 6 months and most particularly at least 12 months.

[0226] The additional solution according to the invention is an aqueous solution comprising at least water. In addition to distilled water or deionized water, water suitable for the invention may also be natural mineral water or floral water.

[0227] According to one embodiment, the mass percentage of water in the additional solution is at least 30%, preferably at least 40%, more particularly at least 50%, better at least 60%, in particular between 70% and 98%, preferentially between 75% and 95%, relative to the total weight of the additional solution.

[0228] The additional solution according to the invention is an aqueous solution which additionally comprises at least one salt, more particularly at least one monovalent or divalent ion such as K+, Na+, Ca++ or Mg++.

[0229] The salt may be chosen from monovalent salts, preferably sodium salts such as sodium chloride, potassium salts such as potassium chloride; or polyvalent, in particular divalent, preferably from calcium salts such as calcium chloride, calcium gluconate, calcium citrate, calcium carbonate, magnesium salts such as magnesium sulfate, and mixtures thereof, and preferably, the salt is a monovalent salt, more particularly sodium chloride.

[0230] Preferably, the additional solution does not contain any carbomer (or acrylic polymer).

[0231] Preferably, the additional solution does not contain any base, in particular NaOH.

[0232] Therefore, the additional solution is different from the solution for increasing viscosity described in WO2015055748.

[0233] Of course, the person skilled in the art will ensure that the salt(s) and / or amount(s) thereof are chosen according to the gelling agent(s) under consideration, in particular its ability to gel in the presence of at least one salt, the solubility limit of the salt(s) under consideration, and in such a way that the advantageous properties of the dispersion according to the invention are not or not substantially altered by the intended addition. Such adjustments belong to the general knowledge of the person skilled in the art.

[0234] The aqueous solution (62) may advantageously contain from 0.01% to 30%, preferably from 0.1% to 20%, better still from 1% to 15% and even from 2% to 10% of salt(s) by weight of the salt(s) relative to the total weight of the aqueous solution (62).

[0235] The weight ratio of "hydrophilic gelling agent(s) susceptible to gelling in the presence of at least one or more salts" is advantageously between 0.1 and 20, better still between 0.2 and 20, more particularly between 0.5 and 15, preferably between 1 and 10, better still between 2.5 and 5.

[0236] One or more additional compounds

[0237] According to the invention, the continuous aqueous phase and / or the dispersed fatty phase and / or the additional solution, or even the third phase 19, may further comprise at least one additional compound different from the abovementioned oils and gelling agents.

[0238] According to the invention, the continuous aqueous phase and / or the dispersed fatty phase and / or the additional solution, or even the third phase 19, may therefore further comprise powders; colorants, in particular chosen from water-soluble or water-insoluble, fat-soluble or fat-insoluble, organic or inorganic colorants, optical effect materials, liquid crystals and mixtures thereof; fillers, more particularly pigments and / or pearl layers, as described in FR3067930; emulsifiers and / or non-emulsifier silicone elastomers, in particular as described in EP2353577; additional hydrophilic gelling agents (or feel agents) other than the above-mentioned hydrophilic gelling agents that readily gel in the presence of at least one salt; glycerol; preservatives; moisturizers; stabilizers; pH stabilizers, more particularly pH buffers (e.g. HEPES, PBS); chelating agents; softeners; retarders, etc., or any useful cosmetic additives; and mixtures thereof.

[0239] Likewise, the continuous aqueous phase and the dispersed fatty phase and / or the additional solution, or even the third phase 19, may further comprise at least one biological and / or cosmetic active agent selected from moisturizers, healing agents, depigmenting agents, UV filters, peeling agents, antioxidants, active agents that promote the synthesis of dermal and / or epidermal macromolecules, skin relaxants, antiperspirants, soothing agents, anti-aging agents, fragrances, anticoagulants, anticoagulants, antimitotic agents, antiproliferative agents, antiadhesive agents, antimigratory agents, cell adhesion promoters, growth factors, antiparasitic molecules, anti-inflammatory drugs, angiogenesis inhibitors, vitamins, hormones, proteins, antifungal agents, antibacterial molecules, preservatives or antibiotics and mixtures thereof. These active ingredients are particularly described in FR1558849.

[0240] Additional hydrophilic gelling agent

[0241] According to certain embodiments, the continuous aqueous phase 16 and / or the additional solution, or even the third phase 19, further comprises at least one additional hydrophilic gelling agent (or "hydrophilic feel agent"), different from the above-mentioned hydrophilic gelling agents susceptible to gelling in the presence of at least one salt.

[0242] As additional hydrophilic gelling agents, i.e. soluble or dispersible in water, mention may be made of:

[0243] - natural gelling agents, in particular chosen from algae extracts, plant secretions, seed extracts, microbial secretions, such as Alcasealan (INCI: Alcaligenes polysaccharide) and other natural agents, more particularly hyaluronic acid,

[0244] - semisynthetic gelling agents, in particular selected from cellulose derivatives and modified starches,

[0245] - synthetic gelling agents, in particular selected from homopolymers of (meth)acrylic acid or one of its esters, copolymers of (meth)acrylic acid or one of its esters, copolymers of AMPS (2-acrylamido-2-methylpropanesulfonic acid), associative polymers,

[0246] - Other gelling agents, selected from clay, silica, such as Silica marketed as 90 / 130 / 150 / 200 / 300 / 380, and

[0247] - A mixture thereof.

[0248] "Associative polymer" as defined in the present invention refers to any amphiphilic polymer that contains at least one aliphatic chain and at least one hydrophilic moiety in its structure; the associative polymers according to the present invention can be anionic, cationic, nonionic or amphoteric; they are also described in FR 2 999 921. Preferably, as described below, the same applies to amphiphilic and anionic associative polymers as well as amphiphilic and nonionic associative polymers. Additional hydrophilic gelling agents are described in more detail in FR3041251.

[0249] Additional hydrophilic gelling agents are especially Sucraclear HC-31 (INCI: Carrageenan (and) Cellulose Gum (and) Carob Gum (and) Glucose) or Sucraclear V2 (INCI: Cellulose Gum, Carrageenan, Locust Bean Pectin, Glucose), preBIULIN C90 (INCI: Cellulose Gum (and) Xanthan Gum (and) Inulin (and) Cellulose (and) Glucose (and) Fructose) and mixtures thereof.

[0250] The aqueous phase may further comprise at least one setting retarder. Depending on the selected manufacturing method, the presence of such a setting retarder in the aqueous phase (16) or (22) can advantageously reduce the gelation kinetics of the ion-sensitive hydrophilic gelling agent, thus preventing the clogging of the microfluidic channels and therefore mechanically enhancing the stability and robustness of the manufacturing method. The setting retarder is preferably a chelating agent, more particularly selected from at least one organic phosphate, and better still sodium pyrophosphate.

[0251] Of course, those skilled in the art will ensure the selection of one or more possible additional compounds and / or their amounts in the composition such that the advantageous properties of the dispersion according to the present invention are not altered or substantially altered by the envisaged mixture. Similarly, those skilled in the art will ensure the selection of the nature and / or amount of one or more additional compounds according to the aqueous or fatty nature of the phase considered and / or relative to the manufacturing method of the dispersion.

[0252] Such adjustment belongs to the general knowledge of those skilled in the art.

[0253] method

[0254] Steps (i) and (ii)

[0255] Steps (i) and (ii) of the method according to the present invention belong to the basic skills of those skilled in the art.

[0256] As for step (ii), a hydrophilic gelling agent that readily gels in the presence of at least one salt may be added to the aqueous phase 16 at ambient temperature or at a temperature above ambient temperature, in particular at a temperature between 60° C. and 90° C. Preferably, when the addition is carried out at a temperature below 60° C., such as ambient temperature, the aqueous phase also comprises at least one sequestering agent selected from sodium citrate, phosphates, ethylenediaminetetraacetic acid (or EDTA), trisodium ethylenediamine disuccinate (such as sold by Innospec under the name Natrlquest E30), sodium gluconate, phytic acid and mixtures thereof. The presence of such a sequestering agent may reduce the hydration temperature of the hydrophilic gelling agent that readily gels in the presence of at least one salt.

[0257] Steps (iii) and (iv)

[0258] Steps (iii) and (iv) of the method according to the present invention can be carried out according to microfluidic methods such as those described in WO2012 / 120043, WO2015 / 055748 or WO2019 / 145424.

[0259] Step (vi)

[0260] The first method according to the invention comprises at least a step (vi) based on the above step (vi1). In view of the above, step (vi1) precedes step (iii) and therefore precedes the step of contacting the aqueous phase 16 and the fatty phase 14.

[0261] More particularly, step (vi1) is considered when the process according to the invention comprising step (vi2) produces a dispersion in which the viscosity of the continuous gelled aqueous phase (22) is high, which is undesirable. In fact, under certain conditions, the inventors have observed that, in the dispersion obtained with the process according to the invention comprising step (vi2), the viscosity of the gelled continuous aqueous phase (22) is sometimes degraded.

[0262] However, reducing the content of the hydrophilic gelling agent that is easily gelled in the presence of at least one salt and / or the salt content according to this method of the present invention based on step (vi2) will definitely reduce the viscosity of the gelled continuous aqueous phase (22), but sometimes impairs the suspendability of the droplets (G1), which is not ideal.

[0263] Contrary to all expectations, the inventors have observed that, prior to step (iii), a gelled continuous aqueous phase (22) can start to form or can even form, while remaining compatible with the microfluidic constraints.

[0264] More particularly, before step (iii), step (vi1) comprises at least the following steps:

[0265] (a) adding an aqueous solution (62) to an aqueous phase (16), preferably at a temperature above ambient temperature, more particularly at a temperature between 40°C and 100°C, or even at a temperature between 50°C and 90°C, most particularly at a temperature between 60°C and 80°C;

[0266] (b) returning the mixture obtained in step (a) to ambient temperature; and

[0267] (c) Optionally, shearing the mixture obtained in step (b).

[0268] Step (a) is advantageously carried out at a temperature above ambient temperature in order to improve or even accelerate the creation of a homogeneous mixture between the aqueous solution (62) and the aqueous phase (16).

[0269] Step (b) ensures that the mixture obtained in step (a) returns to ambient temperature, whereby the viscosity of said mixture increases over time until it reaches its maximum value.

[0270] According to a first variant, step (b) is carried out at ambient temperature for a time sufficient for the viscosity of the mixture obtained in step (a) to reach its maximum value, which time may be between 30 minutes and 5 hours, preferably between 1 hour and 3 hours.

[0271] Said time is within the ordinary skill of those skilled in the art.

[0272] According to a second variant, step (b) is carried out at a temperature below ambient temperature, more particularly at a temperature lower than or equal to 20° C., preferably lower than or equal to 15° C. or even lower than or equal to 10° C. The advantage of the second variant is that it makes it possible to accelerate the cooling of the gelled continuous aqueous phase (22) and thus to obtain more quickly the maximum viscosity of the gelled continuous aqueous phase (22).

[0273] Step (c) is optional and aims at shearing the mixture obtained in step (b). Shearing serves to reduce the viscosity of the gelled continuous aqueous phase (22) without changing its suspension properties nor its visual appearance, in particular without changing its transparency. Shearing can also optimize the stability of the viscosity and its suspending power, in particular when the gelled continuous aqueous phase (22) is subsequently heated, for example to a temperature between 50° C. and 90° C., and the resistance of the gelled continuous aqueous phase (22) to shearing and shaking.

[0274] The second method according to the present invention comprises at least a step (vi) based on the above-mentioned step (vi2).

[0275] According to the second method of the present invention, Figure 3 The device 30 shown is implemented using microfluidics methods.

[0276] The apparatus 30 includes a nozzle 32 for forming the droplets 12 , a platform 31 for injecting an additional solution, and a container 33 for containing the formed droplets 12 .

[0277] In the case of a monodispersion, the forming nozzle 32 includes at least one internal pipeline 34 for introducing an internal fluid 36 containing a fat phase 14, and an external circulation pipe 38 arranged around the internal pipeline 34 for introducing and flowing an external fluid 40 containing an aqueous phase 16.

[0278] The device 30 also comprises conveying means 46 for introducing the internal fluid 36 into the internal pipeline 34 and conveying means 48 for introducing the external fluid 40 into the annular space defined between the internal pipeline 34 and the external pipeline 38 .

[0279] exist Figure 3 In the example shown, the maximum diameter of the lines 34 and 38 is less than 3 mm to maintain the microfluidic nature of the method.

[0280] The inner line 34 is advantageously arranged coaxially in the outer line 38. The inner line is connected upstream to the delivery device 46. The inner line opens downstream via a downstream opening 54 arranged in the outer line 38.

[0281] The outer pipeline 38 and the inner pipeline 34 define an annular space connected upstream to the delivery device 48 .

[0282] The external line 38 has a downstream opening 55 which is located above and at a distance from the container 33. The external line 38 protrudes into the injection platform of the solution 62.

[0283] Delivery devices 46 and 48 each include, for example, a syringe plunger, a peristaltic pump, or another pressure generating system that controls flow rate, such as a pressure tank connected to a flow meter and flow regulation system.

[0284] Each of the delivery devices 46 and 48 is adapted to deliver the respective fluid 36 and 40 at a controlled and adjustable flow rate.

[0285] In the case of a multiple dispersion, the forming nozzle 32 comprises at least one internal line 34 for introducing a third internal fluid 36 comprising the third phase 19 and an intermediate line 37 arranged around the internal line 34 for introducing an intermediate fluid 39 intended to form the fatty phase 14 .

[0286] Figure 4 and Figure 5 Such an embodiment is shown.

[0287] The forming nozzle 32 further includes an external circulation pipe 38 which is arranged around the internal pipeline 34 and / or the intermediate pipeline 37 and is used to introduce and flow an external fluid 40 containing the water phase 16 .

[0288] The device 30 also comprises a conveying device 46 for introducing the inner fluid 36 into the inner pipeline 34 , a conveying device 47 for introducing the intermediate fluid 39 into the intermediate pipeline 37 , and a conveying device 48 for introducing the outer fluid 40 into the annular space defined between the inner pipeline 34 and the outer pipeline 38 .

[0289] exist Figure 5 In the example shown, the maximum diameter of the lines 34, 37 and 38 is less than 3 mm in order to maintain the microfluidic nature of the method.

[0290] The inner line 34 is advantageously arranged coaxially in the outer line 38. This inner line 34 is connected upstream to the delivery device 46. This inner line 34 emerges downstream through a downstream opening 52 arranged in the outer line 38, which is arranged rearward relative to the downstream opening 54 defined by the intermediate line 37, above the opening 54.

[0291] According to a first variant, the distance between the downstream opening 52 of the internal line 34 and the downstream opening 54 of the intermediate line 37 is preferably greater than 1 times the diameter of the intermediate line 37 .

[0292] According to the second variant, the distance between the downstream opening 52 of the inner line 34 and the downstream opening 54 of the intermediate line 37 is preferably less than 1 times the diameter of the intermediate line 37, and even advantageously, the downstream opening 52 of the inner line 34 and the downstream opening 54 of the intermediate line 37 are located on the same horizontal plane.

[0293] The intermediate line 37 extends around the inner line 34. The intermediate line 37 and the inner line 34 delimit an annular space connected upstream to the delivery device 47. The intermediate line 37 protrudes through a downstream opening 54.

[0294] The outer pipeline 38 and the intermediate pipeline 37 and / or the inner pipeline 34 delimit an annular space connected upstream to the delivery device 48 .

[0295] The external line 38 has a downstream opening 55 which is located above and at a distance from the container 33. The external line 38 extends into the injection platform 31 for the additional solution.

[0296] Delivery devices 46, 47 and 48 each include, for example, a syringe plunger, a peristaltic pump or another pressure generating system to control the flow rate, such as a pressure tank connected to a flow meter and a flow rate regulation system.

[0297] Each of the delivery devices 46, 47 and 48 is adapted to deliver the respective fluid 36, 39, 40 at a controlled and adjustable flow rate.

[0298] For both variants of the embodiment of the second manufacturing method described above, the platform 31 comprises at least one line 60 for injecting a solution 62 and means 64 for introducing the solution 62 into the line 60 .

[0299] exist Figure 3 In the example shown, the platform 31 comprises a peripheral line 60 for injecting a solution 62 .

[0300] The peripheral line 60 extends at the periphery of the external circulation pipe 38 parallel to (and in the present case coaxially with) the local axis of the external line 38. The downstream opening 55 of the external line 38 extends into the peripheral line 60.

[0301] Downstream of the downstream opening 55 , the peripheral line 60 defines a dispensing opening 66 which enters the container 33 or is situated above the container 33 .

[0302] exist Figure 3 In the example shown, the peripheral line 60 delimits with the external line 38 an annular space which projects upstream of the dispensing opening 66 .

[0303] Thus, the peripheral line 60 is configured to allow the injection of the solution 62 just at the outlet of the external circulation pipe 38 , coaxially with the axis of circulation of the dispersion containing the droplets 12 and the aqueous phase 16 .

[0304] In the present example, the peripheral line 60 is suitable for collecting the droplets 12 and the aqueous phase 16 supplied with the solution 62 and for conveying them to the dispensing opening 66 .

[0305] The delivery device 64 includes a tank 68 containing the solution 62 and a delivery unit (not shown).

[0306] The delivery unit comprises, for example, a syringe plunger, a peristaltic pump or another pressure generating system to control the flow rate, such as a pressure tank connected to a flow meter and a flow regulation system.

[0307] For both alternative embodiments of the second manufacturing method described above, the container 33 is arranged below the dispensing opening 66 .

[0308] In a variant, the container comprises a liquid volume 70 intended to form part of the second phase 16 , advantageously comprising an outer fluid volume 40 .

[0309] Furthermore, the upper surface of the fluid volume 70, taken along the axis AA' of the pipeline 60, is axially away from the dispensing opening 66, so that the droplets 12 dispersed in the second phase 16 drip under the effect of their weight through the air volume between the dispensing opening 66 and the upper surface of the liquid volume 70. In a variant (not shown), the downstream opening 66 is immersed in the liquid volume 70.

[0310] exist Figure 3 and Figure 5 In the example shown, the device 30 shows only one nozzle 32 , associated with only one platform 31 .

[0311] exist Figure 8 In the advantageous variant shown, the system 30 comprises a plurality of nozzles 32, all connected downstream of a common platform 31, the nozzles 32 being arranged in parallel above a container 33. At least one of the nozzles 32 is laterally offset relative to the platform 31. A collection circuit is provided for collecting the droplets 12 in the liquid 40 at the outlet of each nozzle 32, so as to collect the droplets 12 and bring them to the platform 31.

[0312] A second method for producing a monodispersion according to the invention will now be described. Figure 3 The device shown is implemented.

[0313] First, an internal fluid 36 is prepared. The fatty phase 14 comprises at least one oil and optionally at least one lipophilic gelling agent, more particularly a thermosensitive agent.

[0314] An external fluid 40 is also prepared. The aqueous phase 16 comprises at least water and at least one hydrophilic gelling agent susceptible to gelling in the presence of at least one salt.

[0315] For obvious reasons, the step of mixing the constituent compounds of the fatty phase 14 and the aqueous phase 16 is carried out under conditions suitable for forming a fluid phase compatible with the microfluidic method according to the invention. More particularly, if necessary, the step of mixing the constituent compounds of the fatty phase and / or the step of mixing the constituent compounds of the fatty phase are carried out under thermal conditions, in particular at a temperature between 60° C. and 100° C., preferably between 70° C. and 90° C. This is particularly the case when the phase comprises at least one thermosensitive gelling agent or is intended to facilitate the incorporation of the starting materials into the solvent under consideration.

[0316] Advantageously, the inner fluid 36 and / or the outer fluid 40 may also contain at least one additional compound as described above.

[0317] An aqueous solution 62 is also prepared.

[0318] The inner fluid 36 and the outer fluid 40 are then arranged in corresponding delivery devices 46 and 48, respectively.

[0319] The aqueous solution 62 is arranged in a delivery device 64 .

[0320] Alternatively, the liquid 70 formed of an aqueous solvent having properties similar to those of the external fluid 40 is supplied into the container 33 .

[0321] The conveying devices 46, 48 and 64 are then activated.

[0322] The flow of the internal fluid 36 circulating in the internal line 34 coaxially enters the line 38 at the downstream opening 54 of the internal line 34 .

[0323] At the downstream opening 54 of the inner line 34 , the droplets 12 of the inner fluid 36 are surrounded by the outer fluid film 40 .

[0324] The droplet 12 then circulates in the external fluid 40 towards the downstream opening 55 .

[0325] Then, the droplet 12 in the external fluid 40 enters the platform 31 .

[0326] Then, the solution 62 is injected into the external fluid 40 coaxially with the flow of the droplets 12 at the periphery of the external fluid 40. The solution 62 diffuses into the external fluid 40 during transportation through the downstream portion of the peripheral line 60.

[0327] Therefore, after the formation of the droplets 12, the viscosity of the external fluid 40 is increased, in particular in order to ensure satisfactory suspension of the droplets 12 in the external fluid 40 and / or in order to achieve a desired texture.

[0328] All or part of the increase in viscosity occurs near the dispensing opening 66 prior to introducing the dispersion 10 into the container 33 , before, simultaneously with, and / or after injection of the solution 62 .

[0329] Then, at the dispensing opening 66 , at least one droplet 12 is received in the outer droplet 72 of the outer fluid 40 formed at the outlet of the peripheral line 60 .

[0330] When such a liquid is present in container 33 , external droplets 72 fall into container 33 (through an air volume where appropriate) and droplets 12 of first phase 14 remain suspended in gelled aqueous phase 22 formed by external fluid 40 , aqueous solution 62 or even by liquid 70 .

[0331] In a variant, the gelled aqueous phase 22 forms a jet at the outlet of the peripheral line 60 and is collected without being broken up.

[0332] The injection of the solution 62 and the increase in the viscosity of the aqueous phase 16 are therefore carried out in a very non-invasive manner and directly coincident with the production of the droplets 12 .

[0333] The above ensures the use of a sufficiently mobile aqueous phase to allow adequate formation of droplets 12 at the nozzle 32, while ensuring a robust method of manufacturing the droplets. However, the final product contains a continuous phase with a satisfactory viscosity to give it a pleasing texture and form a satisfactory suspension of droplets 12 through a continuous, simple, safe and low-cost manufacturing method.

[0334] Therefore, without using any carbomer or surfactant, the method according to the invention is particularly effective for forming, in a particularly controlled manner, stable droplets 12 stably suspended in the gelled aqueous phase 22, the size of which is greater than 100 μm, more particularly greater than 250 μm, better still greater than 500 μm.

[0335] The method according to the invention limits shearing, since the continuous aqueous phase 16 containing the droplets 12 remains fluid until the very last moment. When the solution 62 is injected, no forces are generated that deform or break up the droplets 12.

[0336] Emulsification is also reduced. Because the thickness through is small, the diffusion time of the solution 62 in the continuous phase 16 is very short. When collected in the container 33, the continuous phase 16 acquires suspension characteristics almost immediately.

[0337] exist Figure 6 and Figure 7 In the variant shown, the peripheral line 60 emerges just at the outlet of the outer line 38. The downstream edge of the peripheral line 60 is located on the same level as the downstream edge of the outer line 38.

[0338] The distribution opening 66 is then located on the same level as the downstream opening 55 of the external circulation pipe 38 .

[0339] Furthermore, the platform 31 comprises a central line 80 for injecting at least a portion of the solution 62 , which extends to the center of the external circulation pipe 38 .

[0340] In this example, the central pipeline 80 extends out just at the outlet of the outer pipeline 38. The downstream edge of the central pipeline 80 is located at the same level as the downstream edge of the outer pipeline 38.

[0341] Therefore, the distribution opening 82 of the central line 80 is located on the same level as the downstream opening 55 of the external circulation pipe 38 and the distribution opening 66 of the peripheral line 60 .

[0342] This configuration reduces the thickness of the stream containing the droplet 12, the external fluid 40 and the solution 62, because the stream is thinned by gravity by permeating into the air volume located at the outlet of the pipeline 38, 60, 80, as shown in FIG. Figure 7 shown.

[0343] The mixing of the solution 62 in the external fluid 40, or even the increase in viscosity, is very uniform.

[0344] A person skilled in the art will ensure that the parameters of the microfluidic manufacturing method are adjusted to guarantee its proper functioning, in particular to ensure the use of phases with appropriate fluidity, in particular such fluidity being achievable by temperature increase and / or sufficient transient shearing of said phases.

[0345] use

[0346] Preferably, at the end of the above-described preparation process, the dispersion according to the invention can be used directly as a composition, in particular a cosmetic composition.

[0347] The invention also relates to the use of the dispersion according to the invention for the preparation of a composition, in particular a cosmetic, pharmaceutical, nutritional or food processing composition, preferably a cosmetic composition, more particularly a care composition and / or a make-up composition for keratinous substances, more particularly the skin.

[0348] The present invention therefore also relates to a composition, in particular a cosmetic composition, more particularly a care composition and / or a make-up composition for keratinous substances, in particular the skin and / or the hair, more particularly the skin, comprising at least one dispersion according to the invention, optionally in combination with at least one physiologically acceptable medium.

[0349] The dispersions or compositions according to the invention can therefore be used in particular in the cosmetics sector.

[0350] Besides the abovementioned ingredients or compounds, it may also contain at least one physiologically acceptable medium.

[0351] The physiologically acceptable medium is generally adapted to the nature of the vehicle in which the composition is to be used, as well as the form in which the composition is packaged.

[0352] According to one embodiment, the physiologically acceptable medium is directly represented by the continuous aqueous phase as described above.

[0353] Within the framework of the present invention, "physiologically acceptable medium" means, unless otherwise indicated, a medium suitable for cosmetic application, in particular for applying the composition according to the invention to keratinous substances, in particular the skin and / or the hair, more particularly the skin.

[0354] The cosmetic composition of the invention may be, for example, creams, lotions, serums and gels for use on the skin (hands, face, feet, etc.), foundations (liquids, creams) or bath and shower preparations (salts, foams, oils, gels, etc.), hair products (hair dyes and bleaches), cleaning products (lotions, powders, shampoos), hair products (lotions, creams, oils), styling products (lotions, hair sprays, glitter), shaving products (soaps, foams, lotions, etc.), products intended for application to the lips, sunscreen products, sunless tanning products, skin whitening products and anti-wrinkle products. More particularly, the cosmetic composition of the invention may be an anti-aging serum, a youth serum, a moisturizing serum or a perfume.

[0355] According to one embodiment, the composition of the present invention is in the form of a foundation, a makeup remover, a face and / or body and / or hair care, an anti-aging care, a sunscreen, an oily skin care, a whitening care, a moisturizing care, a BB cream, a concealer corrector or a foundation, a face and / or body cleanser, a shower gel or a shampoo.

[0356] Therefore, in view of the above, the dispersion or composition according to the invention is for oral or external use, preferably for external use, better for external use on keratinous substances, more particularly on the skin, better on the facial skin.

[0357] The care composition according to the invention may in particular be a sunscreen composition, a care cream, a serum or a deodorant.

[0358] The composition according to the invention may be in various forms, in particular in the form of a cream, balm, lotion, serum, gel, gel-cream or spray.

[0359] Therefore, in view of the above, the composition according to the invention is for oral or external use, preferably for external use, better for external use on keratinous substances, more particularly on the skin, better on the facial skin.

[0360] The invention also relates to a non-therapeutic method for the cosmetic care of keratinous materials, in particular the skin and / or hair, more particularly the skin, comprising a step of applying to said keratinous materials at least one dispersion or at least one cosmetic composition as described above.

[0361] The invention also relates to the use of a dispersion or a composition according to the invention for improving the appearance of the skin surface, more particularly for moisturizing the skin and / or reducing wrinkles and fine lines.

[0362] Throughout the specification, unless otherwise specified, the expression "comprising" should be understood as being synonymous with "comprising at least one." Unless otherwise specified, expressions such as "between ... and ...," "from ... to ...," and "ranging from ... to ..." should be understood as including limits.

[0363] A specific example for carrying out the method for obtaining the dispersion 10 according to the invention will now be described. Example

[0364] Unless otherwise stated, in the following examples:

[0365] - Steps (iii) and (iv) are performed by means of a microfluidic device as described in WO 2015055748. The device is suitable for heating the fat phase, or alternatively even the aqueous phase, to 80°C.

[0366] The suspension capacity was evaluated by the following stability test. The dispersion was then packaged in three 30 ml polypropylene (PP) containers filled to halfway. After 1 day at room temperature, each test was subjected to one of three transport tests (one container per test), namely:

[0367] - Roller test (i.e. horizontal circular motion): Wheaton benchmark, performed for 1 hour;

[0368] - Vibration table (ie vertical circular movement): Heidolph Unimax reference 1010, for 1 hour; and

[0369] - 3D mixer (ie random movement): performed for 6 minutes.

[0370] - The flow threshold was assessed using a rheometer shear rate sweep protocol (referenced TA Instruments) according to the method described in A Handbook of Elementary Rheology by HA Barnes (Institute of Non-Newtonian Fluid Mechanics, University of Wales, 2000) or http: / / www.tainstruments.com / pdf / literature / RH025.pdf.

[0371] - The transparency of the gelled continuous aqueous phase is determined as follows: the composition to be tested is poured into a 30 ml volga can, the composition is left at ambient temperature for 24 hours and underneath is placed a white sheet on which a cross of about 2 mm thickness is drawn with black felt. If the cross is visible to the naked eye in daylight at a viewing distance of 40 cm, the composition is transparent or translucent.

[0372] The viscosity, action time and water breakage rate were evaluated using a blind test on a group of 24 women aged between 22 and 45. Each woman applied 0.25 g of the composition to be tested on the forearm.

[0373] The action time can be defined as the application time of the composition being tested, specifically the time a user can apply the composition until complete penetration.

[0374] The water break rate can be defined as the ability of a composition to release or not release water when applied and thus achieve a refreshing and moisturizing effect. In other cases, it refers to the feeling felt when a gel breaks under applied pressure and releases the water it contains.

[0375] Scoring criteria:

[0376] Table 1

[0377]

[0378] *Evaluated at ambient temperature

[0379] Example 1 : Effect of a hydrophilic gelling agent that readily gels in the presence of at least one salt

[0380] In this example, three dispersions were prepared using the microfluidic fabrication method described above, wherein step (vi) was based on step (vi2).

[0381] The composition of the starting phase is shown in Table 2:

[0382]

[0383]

[0384] *Appropriate amount.

[0385] The preparation of FP, AP and BF is within the general knowledge of those skilled in the art. For carrying out steps (iii), (iv) and (vi2), the flow rates are as follows:

[0386] Table 3

[0387] Mutually Flow rate per nozzle (ml / hr) AP 120 FP 16.28 BF 14.28

[0388] The size of the monodisperse droplets of the dispersed fat phase was approximately 1200 μm.

[0389] The results are summarized in the table below.

[0390] Table 4

[0391]

[0392] Example 1 shows that macroscopic dispersions can be produced by microfluidic methods without the use of carbomer by replacing the "carbomer / sodium hydroxide solution" system with a "hydrophilic gelling agent that readily gels in the presence of at least one salt / saline solution".

[0393] Example 1 also shows that the dispersion according to the invention is stable and has satisfactory properties, at least similar to the prior art represented by composition 1A.

[0394] Example 2 : Effect of the content of a hydrophilic gelling agent that readily gels in the presence of at least one salt

[0395] In this example, four dispersions were prepared using the microfluidic manufacturing method described above, wherein step (vi) was dependent on step (vi2). The composition of the starting phase was as follows.

[0396] Table 5

[0397]

[0398]

[0399] The preparation of FP, AP and BF is within the general knowledge of the person skilled in the art. To carry out steps (iii), (iv) and (vi2), the flow rates are the same as described in Example 1.

[0400] The size of the monodisperse droplets of the dispersed fat phase was approximately 1200 μm.

[0401] The results are summarized in the table below.

[0402] Table 6

[0403] 2A 2B 2C 2D Processable by microfluidics ++ ++ ++ ++ Suspension ability of droplets in gelled aqueous phase + +++ ++ +++ Transparency of the gelled aqueous phase +++ +++ +++ +++ No stickiness +++ ++ +++ +++ Action time +++ ++ +++ +++ Water rupture rate ++ +++ ++ ++

[0404] Example 2 shows that the content of a hydrophilic gelling agent which readily gels in the presence of at least one salt makes it possible to adjust the properties of the dispersion according to the invention.

[0405] Example 3 : Effect of salt content in the additional solution

[0406] In this example, six dispersions were prepared using the microfluidic manufacturing method described above, wherein step (vi) was dependent on step (vi2). The composition of the starting phases AP and FP and the flow rates were the same as described above in Example 1B.

[0407] In Example 3, the salt content in the additional solution (BF) was varied according to the following table.

[0408] Table 7

[0409]

[0410]

[0411] The size of the monodisperse droplets of the dispersed fat phase was approximately 1200 μm.

[0412] The results are summarized in the table below.

[0413] Table 8

[0414] standard 3A 3B 3C 3D 3E 3F Processable by microfluidics + ++ +++ +++ ++ + Suspension ability of droplets in gelled aqueous phase + + ++ +++ ++ ++ Flow rate threshold (Pa) 0.5 5 8.5 15.5 7.8 7 Transparency of the gelled aqueous phase +++ +++ +++ +++ +++ +++ No stickiness +++ +++ +++ +++ +++ +++ Action time ++ ++ ++ ++ + + Water rupture rate + + ++ +++ ++ ++

[0415] Example 3 shows that the salt content in the additional solution (BF) is used to adjust the properties of the dispersions according to the invention in terms of suspension ability, mechanical properties and processability.

[0416] Surprisingly, the change in salt content has little effect on the "non-sticky" criterion.

[0417] Example 4 : Manufacture of the dispersions according to the invention

[0418] Example 4 differs from Example 1B in that an additional hydrophilic gelling agent is added to the aqueous phase (AP), which is different from the hydrophilic gelling agent that is prone to gelation in the presence of at least one salt, namely preBIULIN C90 (INCI: cellulose gum (and) xanthan gum (and) inulin (and) cellulose (and) glucose (and) fructose) at 0.3% relative to the weight of the aqueous phase. Similar results were obtained by replacing preBIULIN C90 with Sucraclear HC-31 (INCI: carrageenan powder (and) cellulose gum (and) carob gum (and) glucose) or Sucraclear V2 (INCI: cellulose gum, carrageenan powder (carrageenan), locust bean gum, glucose) at the same concentration.

[0419] The size of the monodisperse droplets of the dispersed fat phase is approximately 1200 μm.

[0420] The results are summarized in the following table.

[0421] Table 9

[0422]

[0423]

[0424] Example 4 shows that the presence of an additional hydrophilic gelling agent (in this case Sucraclear V2) particularly improves the properties of the dispersions according to the invention in terms of microfluidic processability.

[0425] Without wishing to be bound by any theory, the applicant believes that the presence of an additional hydrophilic gelling agent increases the viscosity of the continuous aqueous phase without increasing the content of the hydrophilic gelling agent that is prone to gelation in the presence of at least one salt, which would lead to a significant decrease in feel.

[0426] Example 5 : Manufacture of a dispersion by the method according to the invention comprising steps (vi1) and (vi2)

[0427] In this example, the dispersion was prepared using the microfluidic manufacturing method described above, wherein step (vi) included step (vi1) and step (vi2).

[0428] Example 5 differs from Example 1B in that 0.15% of sodium chloride relative to the weight of the aqueous phase (AP) is added to the aqueous phase (AP).

[0429] Therefore, the additional solution (BF) was adjusted accordingly, as described below.

[0430] Table 10

[0431]

[0432] *Appropriate amount.

[0433] The preparation of FP, AP and BF is within the general knowledge of those skilled in the art.

[0434] The preparation of such mixtures is within the general knowledge of a person skilled in the art.

[0435] The flow rate configuration is as follows:

[0436] Table 11

[0437] Mutually Flow rate per nozzle (ml / hr) AP 120 FP 16.28 BF 14.28

[0438] The size of the monodisperse droplets of the dispersed fat phase was approximately 1200 μm.

[0439] Compared to Example 1B, Example 5 demonstrates the advantageous properties associated with microfluidic methods, primarily during the period between formation of the dispersed phase and injection of additional solution.

[0440] This advantage translates into a more stable and therefore more robust manufacturing process, easier collection and better quality bulk due to the improved suspension of the aqueous phase droplets, thus more effectively preventing emulsification or coalescence of the droplets before the injection of the additional solution (BF).

Claims

1. A method of forming a dispersion (10) comprising droplets (12) of a fatty phase (14), the droplets being dispersed in a gelled continuous aqueous phase (22), the method comprising: The following steps are involved: (i) providing a fatty phase (14) comprising at least one oil and optionally at least one lipophilic gelling agent which is preferably thermosensitive; (ii) providing an aqueous phase (16) which is substantially immiscible with the fatty phase (14), the aqueous phase (16) comprising at least water and at least one hydrophilic gelling agent capable of gelling in the presence of at least one salt; (iii) forming fat phase droplets (14) in the aqueous phase (16) or the gelled continuous aqueous phase (22); (iv) transporting the droplets (12) in a circulation pipe (38); (v) recovering the dispersion (10) comprising the droplets (12) and the gelled continuous aqueous phase (22) in a container (33); Characterized in that the method comprises at least one of the following steps (vi): (vi1) before step (iii), adding at least a portion of the aqueous solution (62) to the aqueous phase (16); and / or (vi2) injecting at least a portion of the aqueous solution (62) into the circulation pipe (38) or at the outlet of the circulation pipe (38) upstream of the container (33), The aqueous solution (62) comprises at least one salt susceptible to reacting with the hydrophilic gelling agent, The dispersion is free of carbomer and optionally free of amodimethicone.

2. The method according to claim 1, It is characterized in that The preparation of the gelled continuous aqueous phase (22) according to step (vi1) comprises at least the following steps: (a) adding the aqueous solution (62) to the aqueous phase (16), preferably at a temperature above ambient temperature, more preferably at a temperature between 40°C and 100°C, or even at a temperature between 50°C and 90°C, most particularly at a temperature between 60°C and 80°C; (b) returning the mixture obtained in step (a) to ambient temperature; and (c) Optionally, shearing the mixture obtained in step (b).

3. The method according to claim 1 or 2, It is characterized in that Said droplets (12) having a diameter greater than or equal to 100 μm represent a volume greater than or equal to 60%, or even greater than or equal to 70%, preferably greater than or equal to 80% and better still greater than or equal to 90% of the total volume of the dispersed phase and / or at least 60%, even at least 70%, preferably at least 80% and better still at least 90% of said droplets have an average diameter greater than or equal to 100 μm.

4. The method according to any one of the preceding claims, It is characterized in that The hydrophilic gelling agent that readily gels in the presence of at least one salt is a polyelectrolyte that is reactive toward at least one salt.

5. The method according to any one of the preceding claims, It is characterized in that The hydrophilic gelling agent that is susceptible to gelling in the presence of at least one salt is chosen from natural polymers, biosynthetic polymers, modified polymers and mixtures thereof, preferably from polysaccharides based on alginate, alginates, pectin, carrageenan, gellan gum, diutan gum, furcellaran or one of their derivatives and mixtures thereof, more particularly from gellan gum and / or carrageenan, most particularly from gellan gum and / or iota-carrageenan.

6. The method according to any one of the preceding claims, It is characterized in that The aqueous phase (16) comprises from 0.01% to 5%, preferably from 0.05% to 2.5%, better still from 0.05% to 1% and most particularly from 0.08% to 0.5% of hydrophilic gelling agent(s) to be gelled in the presence of at least one salt relative to the total weight of said aqueous phase (16).

7. The method according to any one of the preceding claims, It is characterized in that The salt is monovalent, preferably from sodium salts such as sodium chloride, potassium salts such as potassium chloride; or multivalent, especially divalent, preferably from calcium salts such as calcium chloride, calcium gluconate, calcium citrate, calcium carbonate, magnesium salts such as magnesium sulfate, and mixtures thereof, and preferably, the salt is a monovalent salt, more especially sodium chloride.

8. The method according to any one of the preceding claims, It is characterized in that The aqueous solution (62) comprises from 0.01% to 30%, preferably from 0.1% to 20%, better still from 1% to 15%, even from 2% to 10% of salt(s) by weight of the salt(s) relative to the total weight of the aqueous solution (62).

9. The method according to any one of claims 1, 3 to 8, It is characterized in that The droplets (12) and the aqueous phase (16) flow along a local axis in the circulation pipe (38), and the injection of the aqueous solution (62) is performed substantially parallel to the local axis.

10. The method according to any one of claims 1, 3 to 9, It is characterized in that The injection of the aqueous solution (62) is performed at the outlet of the circulation pipe (38).

11. The method according to any one of the preceding claims, It is characterized in that Upstream of process step (iv), the method further comprises the step of forming droplets (12) in the circulation pipe (38).

12. The method according to any one of the preceding claims, It is characterized in that The dispersion (10) comprises from 1% to 60%, more particularly from 5% to 50%, preferably from 10% to 40%, better still from 15% to 30% of dispersed fatty phase (14) by weight relative to the total weight of the dispersion (10).

13. The method according to any one of the preceding claims, It is characterized in that The lipophilic gelling agent is selected from organic or inorganic, polymeric or molecular lipophilic gelling agents; fats that are solid at ambient temperature and pressure; and mixtures thereof.

14. The method according to any one of the preceding claims, It is characterized in that The dispersion (10) comprises from 0.5% to 30%, preferably from 1% to 25%, more particularly from 1.5% to 20%, better still from 2% to 15%, most particularly from 5% to 12% of lipophilic gelling agent(s) by weight of the lipophilic gelling agent(s) relative to the total weight of the fatty phase (14).

15. The method according to any one of the preceding claims, It is characterized in that The aqueous phase (16) and / or the aqueous solution (62) further comprises at least one additional lipophilic gelling agent different from the lipophilic gelling agent susceptible to gelling in the presence of at least one salt.

16. A method according to any one of the preceding claims, It is characterized in that The dispersion does not contain any surfactant.

17. A device (30) for forming a dispersion (10) comprising droplets (12), include: a circulation pipe (38) containing droplets (12) of the fat phase (14) in an aqueous phase (16) which is substantially immiscible with the fat phase (14); a container (33) for recovering the dispersion (10) comprising the droplets (12) and the aqueous phase (16); Characterized in that the device (30) comprises: a tank (68) containing an aqueous solution (62) comprising at least one salt; at least one injection line (60) connected to the tank (68) for injecting the aqueous solution (62) and entering the circulation pipe (38) or at the outlet of the circulation pipe (38) upstream of the container (33), The fatty phase (14) comprises at least one oil and optionally at least one lipophilic gelling agent which is preferably thermosensitive; The aqueous phase (16) which is substantially immiscible with the fatty phase (14) comprises at least water and at least one hydrophilic gelling agent which readily gels in the presence of at least one salt; and The dispersion (10) is free of carbomer and optionally free of amodimethicone.

18. The device (30) according to the preceding claim, It is characterized in that The circulation tube (38) extends along the local axis of circulation of the droplets (12) and the aqueous phase (16), and the injection line (60) extends coaxially with the local axis.

19. A dispersion (10) comprising droplets (12) of a fatty phase (14) dispersed in a continuous gelled aqueous phase (22), in: - said droplets (12) having a diameter greater than or equal to 100 μm represent a volume greater than or equal to 60%, or even greater than or equal to 70%, preferably greater than or equal to 80% and better still greater than or equal to 90% of the total volume of the dispersed phase and / or at least 60%, even at least 70%, preferably at least 80% and better still at least 90% of said droplets have a mean diameter greater than or equal to 100 μm; - the fatty phase comprises at least one oil and optionally at least one lipophilic gelling agent which is preferably thermosensitive; and - the gelled continuous aqueous phase comprises at least water, at least one hydrophilic gelling agent gelled by at least one salt, The dispersion is free of carbomer and optionally free of amodimethicone.

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