SHELL-FREE STABLE DISPERSION

Abstract

A dispersion comprises a dispersed phase comprising drops and a continuous aqueous phase, preferably in gel form, wherein the drops comprise a fatty phase comprising at least one lipophilic gelling agent, wherein: the fatty phase has a melting point between 50° C. and 100° C., preferably between 60° C. and 90° C., and, at room temperature and atmospheric pressure, meets the following physicochemical criteria: a hardness (x) of between 2 and 14 N, preferably between 2.5 and 12 N, more preferably between 3 and 9 N, and most preferably between 4 and 6 N; and an adhesiveness (y) greater than or equal to −2 N, and better still, greater than or equal to −1 N, and in particular greater than or equal to −0.6 N; and the dispersion does not comprise amodimethicone.

Claims

1. A dispersion comprising a dispersed phase comprising drops and a continuous aqueous phase, wherein the drops comprise a fatty phase comprising at least one lipophilic gelling agent, wherein: the fatty phase has a melting point between 50° C. and 100° C., and, at room temperature and atmospheric pressure, meets the following physicochemical criteria: a hardness (x) of between 2 and 14 N; and an adhesiveness (y) greater than or equal to −2 N; and the dispersion does not comprise amodimethicone.

2. The dispersion according to claim 1, wherein the fatty phase has a cohesiveness (z) of less than or equal to 40.

3. The dispersion according to claim 1, wherein the dispersion does not comprise a shell.

4. The dispersion according to claim 1, wherein the drops having a diameter greater than or equal to 100 μm represent a volume greater than or equal to 60%, and/or at least 60% of the drops have an average diameter greater than or equal to 100 μm.

5. The dispersion according to claim 1, wherein the lipophilic gelling agent is selected from organic or inorganic, polymeric or molecular lipophilic gelling agents; solid fats at ambient temperature and pressure; and mixtures thereof.

6. The dispersion according to claim 1, comprising from 0.5% to 30% by weight of lipophilic gelling agent(s) relative to the total weight of the fatty phase.

7. The dispersion of claim 1, wherein the continuous aqueous phase comprises at least one hydrophilic gelling agent.

8. The dispersion according to claim 7, comprising from 0.0001% to 20% by weight of hydrophilic gelling agent(s) based on the total weight of the continuous aqueous phase.

9. The dispersion of claim 1, comprising from 1% to 60% by weight of dispersed fatty phase relative to the total weight of the dispersion.

10. The dispersion of claim 1, wherein the dispersion does not comprise surfactants.

11. The dispersion claim 1, wherein the dispersion does not comprise: dextrin ester and fatty acid(s), and/or optionally hydrophobically treated silica, and/or Acrylates/C10-30 Alkyl Acrylate Crosspolymer, and/or Cetyl Ethylhexanoate.

12. A method of preparation a dispersion according to claim 1, comprising at least the following steps: a) heating an oily fluid Fl to a temperature from 50° C. to 150° C.; b) optionally heating an aqueous fluid FE to a temperature from 50° C. to 150° C.; c) bringing the aqueous fluid FE and the oily fluid Fl into contact; and d) forming drops of fatty phase, consisting of the oily fluid Fl, dispersed in a continuous aqueous phase, consisting of aqueous fluid FE, wherein: the oily fluid Fl comprises at least one lipophilic gelling agent and optionally at least one oil and has a melting point between 50° C. and 100° C., and, at room temperature and atmospheric pressure, meets the following physicochemical criteria: a hardness (x) of between 2 and 14 N; and an adhesiveness (y) greater than or equal to −2 N; the oil fluid Fl further being free of amodimethicone; and the aqueous fluid FE comprises at least water and, optionally, at least one hydrophilic gelling agent.

13. The method according to claim 12, wherein the drop formation step comprises forming drops of oily fluid Fl at the outlet of a first conduit opening into the aqueous fluid FE.

14. The method according to claim 13, wherein the aqueous fluid FE is circulated in a second conduit, the outlet of the first conduit opening into the second conduit.

15. A dispersion obtained by a method according to claim 12.

16. A composition comprising at least one dispersion of claim 1, optionally in combination with at least one physiologically acceptable medium.

17. A non-therapeutic method for the cosmetic treatment of a keratinous material, comprising a step of applying to said keratinous material at least one dispersion according to claim 1.

18. A non-therapeutic method for the cosmetic treatment of a keratinous material, comprising a step of applying to said keratinous material a composition according to claim 16.

Description

[0263] The corresponding measurements are shown in FIGS. 1 to 7.

[0264] FIG. 1 is a graph representing the hardness criterion (x) of the anhydrous gels in Table 1.

[0265] FIG. 2 is a graph representing the adhesiveness criterion (y) of the anhydrous gels in Table 1.

[0266] FIG. 3 is an enlargement of FIG. 2 of the adhesiveness values (y) of the anhydrous gels 2A, 2B, 2C, 3A, 3B, 3C, 5 and 6.

[0267] FIG. 4 is a graph showing the cohesiveness criterion (z) of the anhydrous gels 1B, 1D, 2B, 3B, 5 and 6 from Table 1.

[0268] Finally, FIGS. 5 to 7 are graphs representing the texturometry curves of the anhydrous gels in Table 1. These FIGS. 5 to 7 show the force (in N) of the gels in Table 1 as a function of the time (in seconds) during which the gels are subjected to (1) a first compression step (0 to 5 s) and then (2) a second relaxation step where the mobile rises (5 to 10 s). The previous steps (1) and (2) are repeated. These FIGS. 5 to 7 therefore provide information on the physicochemical properties of the gels in Table 1, particularly in terms of hardness, adhesiveness and cohesiveness.

RESULTS

[0269] Hardness (x): as shown in FIG. 1, with the same percentage of lipophilic gelling agent and oil solvent (e.g. 1B vs 2B vs 3B), the differences in the hardness profiles of the different anhydrous gels tested are not significant. Furthermore, from tests 10 and 1 D, it can be seen that the hardness is impacted by the nature of the solvent. Adhesiveness (y): As shown in FIGS. 2 and 3, with the same percentage of lipophilic gelling agent and oil solvent: [0270] gels 2 (A, B, C), 3 (A, B, C), 5 and 6 have similar adhesiveness profiles, and [0271] gels 1 (B, C) and 4 show significantly better adhesiveness than gels 2 (A, B, C) and 3 (A, B, C).

[0272] Furthermore, from tests 1C and 1 D, it is observed that the nature of the solvent has an impact on the tackiness. [0273] Cohesiveness (z): As shown in FIG. 4, gels 2B, 3B, 5 and 6 show similar physicochemical properties in terms of cohesiveness, which are significantly lower than those of gels 1B and 1 D.

Example 2: Preparation of Macroscopic Dispersions

[0274] In this example 2, ten dispersions are prepared comprising a continuous aqueous phase and a dispersed phase in the form of drops, each represented by one of the anhydrous gels of example 1. These dispersions are obtained using a microfluidic manufacturing method as described in WO2015/055748. The microfluidic system used is divided into two parts, a first part in which the fatty phase (also designated IF or FI) and the aqueous phase (also designated OF or FE) are brought into contact at high temperature (between 70 and 90° C.) in order to form the dispersion, and a second part which ensures rapid cooling of the dispersion formed in order to accelerate the kinetics of gelling of the drops and thus prevent the risks of coalescence and fragmentation of the drops after formation (between 10 and 30° C.).

[0275] The compositions of the phases (fluids) for the preparation of the dispersions are described in Table 3 below.

TABLE-US-00003 TABLE 3 % w/w % w/w Fluid Name INCI Phases final IF Anhydrous gel according to example 1 — 10 (gelled fatty phase) OF Osmosis water Aqua Qsf* Qsf* (continuous Microcare PE Phenoxyethanol, 0.99 0.80 aqueous aqua phase) Microcare Pentylene glycol, 2.47 2.00 emollient PTG aqua Glycerine codex Glycerin, aqua 9.88 8.00 Zemea Propanediol Propanediol, aqua 8.64 7.00 Butylene Glycol 1.3 Butylene glycol, 6.17 5.00 aqua Edeta BD Disodium EDTA 0.05 0.04 Carbopol ETD 2050 Carbomer 0.33 0.27 polymer Carbopol Ultrez 10 Carbomer 0.10 0.08 polymer Blanose CMC 7HF Cellulose, aqua 0.04 0.03 Sodium hydroxide Sodium hydroxide 0.01 0.01 pellets PRS codex Total 100 81 BF Osmosis water Aqua Qsf Qsf (base) Sodium hydroxide Sodium hydroxide 0.64 0.06 pellets PRS codex Total 100 9 *QSF: quantity sufficient for

[0276] Preparation Protocol:

[0277] For the OF: [0278] Mixture A: while stirring in a deflocculator, Phenoxyethanol, Pentylene glycol and EDTA are incorporated into water and the resulting mixture is stirred for 5 min. [0279] Mixture B: Carbopol Ultrez 10 polymer carbomer is then sprinkled onto mixture A until hydrated, then stirred for 30 minutes with a paddle. [0280] Mixture C: Carbopol ETD 2050 polymer is then dispersed in mixture B while stirring for 30 minutes using a paddle. [0281] Mixture D: while stirring in a deflocculator, humectants (i.e. glycerine, zemea propanediol and butylene glycol 1.3) are added to mixture C. The resulting mixture D is kept stirring for 10 min. [0282] Mixture E: the blanose, previously predispersed at 1% in water under magnetic stirring at 80° C., after returning to room temperature, is added to mixture D while stirring in a deflocculator. [0283] Mixture F: soda is added to mixture E which is stirred for 10 minutes to obtain the OF solution.

[0284] The OF solution is then introduced into an sOF syringe connected to a heater to keep the OF hot (80° C.).

[0285] For IFs: see protocol described in example 1.

[0286] Each of the ten heated IF solutions is then introduced into an sIF syringe connected to a heater to keep the IF hot (80° C.). To reduce heat loss, the microfluidic system was installed directly at the outlet of the sIF and sOF syringes and is itself maintained at 80° C.

[0287] For BF: soda and water are mixed with the aid of a magnetic bar for 5 min. The BF solution is then introduced into an sBF syringe.

[0288] Using the sIF, sOF and SBF syringes and associated syringe plungers, the IF and OF are injected into the microfluidic system and the BF is injected into the dispersion at the outlet of the microfluidic system, at the flow rates described in Table 4 below.

TABLE-US-00004 TABLE 4 Flow rate per nozzle Phase (in mL/hr) OF 100 IF 13.56 BF 11.11

[0289] Depending on the configuration of the microfluidic system and the flow rates, the dispersions obtained may comprise drops with a satisfactory monodispersity and with an average diameter between 100 μm and 1500 μm, in particular between 700 and 1300 μm.

[0290] Results on the Manufacture of Dispersions:

[0291] It was possible to make dispersions from the ten anhydrous gels according to example

[0292] Stability Test

[0293] Each of the ten dispersions is then packed into three 30 mL polypropylene (PP) containers, each half filled. After 1 day at room temperature, each test undergoes one of the following three transport tests (one receptacle per test): [0294] roller test (i.e. horizontal circular motion): Wheaton reference, for 1 hour [0295] vibration table (i.e. vertical circular motion): reference Heidolph Unimax 1010, for 1 hour; and [0296] 3D mixer (i.e. random movements): for 6 minutes.

[0297] At the end of these stability tests, the following are evaluated: (i) the integrity of the drops, in particular their fragmentation and (ii) the turbidity of the gel, generally linked to a transfer of the fatty phase into the continuous aqueous phase.

[0298] Scoring Criteria:

TABLE-US-00005 TABLE 5 SCORING CRITERIA 0 1 2 3 BUBBLE No Slight Average High FRAG- frag- frag- frag- frag- MENTATION mentation mentation mentation mentation GEL TURBIDITY Clear gel Slightly Medium Cloudy gel cloudy cloudy gel gel

[0299] Results:

TABLE-US-00006 TABLE 6 Dispersion* D1A D1B D1C D1D D2A D2B D2C D3A D3B D3C 4 5 6 bubble 3 1 0 1 3 1 0 2 1 0 0 2 2 fragmentation Gel turbidity 3 1 0 1 3 1 0 2 1 0 0 2 2 Conclusion KO OK KO OK KO OK OK OK OK OK OK OK OK *D1A = dispersion according to example 2 using the anhydrous gel 1A of example 1 as the dispersed fatty phase.

[0300] The dispersions D1A and D2A show unsatisfactory stability results. The corresponding fatty phases are therefore excluded from the rest of the study. The D3A dispersion shows average stability results but is considered satisfactory enough to be retained for further study. The other dispersions tested showed satisfactory stability results. These results show that a fatty phase must have properties in terms of hardness greater than 2 N, preferably greater than or equal to 2.5 N, in particular greater than or equal to 3 N, and better still, greater than or equal to 4 N.

[0301] Sensory Testing

[0302] Then, based on the above eight dispersions with satisfactory stability, visual and sensory tests were carried out on a cohort of 24 women aged between 22 and 45. Each woman blindly tested the eight dispersions that were satisfactory in terms of kinetic stability. The criteria evaluated are (i) the adhesion of the dispersed fatty phase drops onto the packaging wall, (ii) the aggregation of the dispersed phase drops with each other and the ease (or comfort) of application, and in particular the ease of crushing and spreading the dispersed phase drops.

[0303] Scoring Criteria:

TABLE-US-00007 TABLE 7 SCORING CRITERIA 0 1 2 3 ADHESION = Lack of Slight Average Strong adhesiveness adhesion adhesion adhesion adhesion (y) AGGRE- Lack of Slight Average Strong GATION = aggregation aggregation aggregation aggregation cohesiveness (z) EASE OF Very Satisfactory Moderately Unsatisfactory APPLICATION satisfactory application. satisfactory application. application. The drops application. The drops The drops are not The drops are felt and are not or only are felt their crushing (or only slightly and their on the slightly) felt and crushing skin generates felt the mixing on the lumps and the between skin that are mixing the generates difficult between aqueous lumps. The to remove by the and fatty application spreading aqueous phases of on the and fatty is easy. dispersion skin. The phases is remains hardness of easy. possible. the drops is too high.

[0304] Results:

TABLE-US-00008 TABLE 8 Dispersion* D1B D1C D1D D2B D2C D3A D3B D3C 4 5 6 Adhesion = 3 3 3 0 1 0 1 1 3 0 0 adhesiveness (y) Aggregation = 2 NR** 2 1 NR** NR** 1 NR** 2 & & cohesiveness (z) Ease of 1 2 1 1 2 0 1 2 3 1 1 application *D1A = dispersion according to example 2 implementing the anhydrous gel 1A of example 1 as the dispersed fatty phase. **NR: No information.

[0305] A fatty phase is observed: [0306] in view of the above results in terms of “ease of application” and FIG. 1, must have a hardness (x) of 14 N or less, preferably 12 N or less, and preferably 9 N or less, [0307] in view of the above results in terms of “adhesion” and of FIGS. 2 and 3, that the fatty phase must have a adhesiveness (y) greater than or equal to −2 N, and better still, greater than or equal to −1 N, or even greater than or equal to −0.6 N, and [0308] in view of the above results in terms of “aggregation” and FIG. 4, that the fatty phase must have a cohesiveness (z) of less than or equal to 40, preferably less than or equal to 35, and better still, less than or equal to 30.

CONCLUSION

[0309] In view of the above results,

[0310] it is observed that a dispersion comprising a dispersed phase comprising drops and a continuous aqueous phase, when the stability of this dispersion is not ensured by the presence of a shell at the “continuous aqueous phase/dispersed fatty phase” interface or of surfactant, can nevertheless and unexpectedly present satisfactory properties in terms of kinetic stability and sensoriality, in particular in terms of comfort and ease of application, on the condition that the gelled fatty phase has:

[0311] (i) a melting point between 50° C. and 100° C., preferably between 60° C. and 90° C., and,

[0312] (ii) at room temperature and atmospheric pressure: [0313] a hardness (x) of between 2 and 14 N, in particular between 2.5 and 12 N, preferably between 3 and 9 N, and more preferably between 4 and 6 N; [0314] an adhesiveness (y) greater than or equal to −2 N, and better still, greater than or equal to −1 N, and in particular greater than or equal to −0.6 N; and [0315] optionally, a cohesiveness (z) of less than or equal to 40, preferably less than or equal to 35, and better still, less than or equal to 30.

[0316] Even more unexpectedly, these results are observed and applicable with a dispersion with dispersed fatty phase drops of macroscopic size.