FR3072288A1 - OIL-IN-WATER EMULSION BASED ON VEGETABLE OILS AND FORMULATED WITHOUT SURFACTANTS - Google Patents

Abstract

The present invention relates to the field of oil-in-water emulsions and more particularly proposes oil-in-water emulsions containing vegetable oils formulated without surfactant or any other substitute substance. .

Description

OIL-IN-WATER EMULSION BASED ON VEGETABLE OILS AND FORMULATED WITHOUT SURFACTANT

The present invention relates to the field of oil-in-water emulsions and more particularly provides oil-in-water emulsions based on vegetable oils formulated without surfactant or any other substitute substance.

PRIOR ART

The preparation of emulsions without surfactant has been a subject of interest in the fields of cosmetics and pharmacopoeia for many years. Most of the solutions proposed to date relate to the use of particular substances, not classified as surfactants, but whose role in formulation is to compensate for the absence thereof. US patent 6,416,748 proposes for example the use of a crosslinked polymer of at least one ethylenically unsaturated monomer, while patent FR2750327 proposes to use a crosslinked and neutralized poly (2-acrylamido 2-methylpropane sulfonic acid). These solutions are thus based on the use of large molecules, which stabilize the emulsion by the structuring they impose on their environment. The patents FR2722116 and FR2720644, for their part, provide examples of the use of solid particles which ensure the dispersion of one of the two phases in the other. These particles also have the advantage of offering more advantageous product textures for the consumer. Other solutions are proposed by patents CA2295533 and FR2771293, which respectively describe the use of a cationic gel and a lipophilic agent whose hydrophilic / lipophilic balance (HLB) is less than 3. The stability of the preparations produced is then provided by the structuring that these compounds allow at the hydrophilic / lipophilic interface.

The direct dispersion of vegetable oil in water or any other aqueous solution is not possible without special technologies.

ADVANTAGES OF THE INVENTION

It appears from the state of the prior art that there are currently no proposals allowing the preparation of emulsified products of the “oil-in-water” type not containing any substance, of any kind, to ensure stability. It would be interesting to propose a new galenic, without surfactant molecule, allowing to have products with a more pleasant texture, without fatty sticky effect on application, with a soft touch and which dry quickly on the skin.

Thus, the invention relates to very simple compositions, consisting of an emulsion of a vegetable oil in an aqueous solution, this aqueous solution preferably being a hydrosol. Remarkably, these compositions are stable in the absence of any surfactant molecule and pleasant to use. These compositions containing only vegetable oils and an aqueous phase constitute a new and innovative dosage form.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to novel short and simple dosage formulations of vegetable oils (HV) for use in natural cosmetics. These formulations are stable emulsions of HV in an aqueous solution without the addition of surfactant. Such emulsions can be obtained for example using the process using high frequency ultrasound, as described in patent application WO2010 / 149668.

A first object of the invention therefore relates to a composition of the oil-in-water emulsion type comprising an aqueous solution and at least one HV, this composition containing no surfactant.

Within the meaning of the invention, the compositions do not contain a surfactant, an emulsifier, or any other substance or particle intended to stabilize the preparation with respect to phase separation.

The nature of the aqueous solution used to prepare the emulsion can be diverse. It is preferably an aqueous solution containing plant extracts, in particular a hydrosol, an infusion or a maceration of plants, or a fruit water. In a preferred embodiment, the aqueous solution is a hydrosol, pure or diluted, or a mixture of hydrosols.

The amount of HV contained in the compositions must be adapted according to the nature of the HV and the use which it is desired to make of it. Indeed, certain vegetable oils such as avocado oil or argan oil are suitable for dry skin, while others will be recommended for combination or oily skin such as black cumin or hazelnut oil. The products obtained after emulsification can be used directly, for example in topical application. Thus, the proportion of HV contained in the compositions is generally between 2% and 50%, preferably between 15% and 30%. In a particular embodiment, the amount of HV is between 3 and 5%.

In another particular embodiment, the invention relates to compositions consisting of an emulsion of one or more HV in one or more aqueous solutions, in particular in one or more hydrosols.

In another particular embodiment, the vegetable oil and the hydrosol come from the same plant, for example a rose hydrosol and a rose vegetable oil.

In other embodiments, emulsions can be obtained from a mixture of aqueous solutions and / or a mixture of HV or from emulsions mixed together.

Emulsions containing an aqueous solution and HV, excluding any texturing agent, are liquid. In order to facilitate handling and use, gelling agents can be added without this altering the emulsion, in particular its properties. Thus, the compositions according to the invention can contain gelling agents, preferably of natural origin, such as xanthan gum or alginates.

The addition of gelling agents respects the naturalness and purity of the product and makes it possible to obtain a creamier and more pleasant texture when applied to the skin. The texture of the composition will depend on the amount of gelling agent added.

To obtain a lotion-type composition with a liquid appearance, the proportion of gelling agent will generally be less than 0.1%, preferably equal to 0% of the composition.

To obtain a milk-type composition, of flowing appearance but not sprayable, the proportion of gelling agent will generally be between 0.1% and 0.8% of the composition.

To obtain a gel-type composition, of non-flowing appearance, the proportion of gelling agent will generally be between 0.8% and 2% of the composition.

To obtain a composition of poultice or mask type, with a thick and creamy appearance, the proportion of gelling agent will generally be between 2% and 5% of the composition.

The texture being dependent on the temperature, these indications correspond to the appearance of the compositions at room temperature, that is to say at a temperature of approximately 20 ° C., and generally between 15 ° C. and 27 ° C.

The gelling agents are added after emulsification according to the desired texture.

On the other hand, moisturizers, preferably of natural origin, can be added to the composition, for example glycerin.

When moisturizers are added, their proportion is generally between 2% and 10% of the composition.

In general, the hydrating agents can be added before or after emulsification; however, if the agents are hydrophobic, they will be added before emulsification.

It is also possible to add, if necessary, an acidity corrector to adjust the pH of the composition as close as possible to that of the skin. This acidity corrector can be added either during the process or at the end of the process.

For better preservation of the compositions over time, it may be necessary to add antimicrobial products and / or antioxidants. It is particularly important to avoid the rancidity of HV, which can become comedogenic. The percentage of antimicrobial product and / or antioxidants required varies depending on the product's own activity and the composition itself.

Some organic natural preservatives can be cited as an example:

- Naticide 0.6% for pH: 4 <pH <9,

- INCI "Fragrance" (not considered to be preservative on INCI although its conservation properties have been demonstrated)

- Cosgard 0.6% for pH <7

- Leucidal 2.25% for pH <9

- 0.75% benzoate sorbate complex for pH <5.5

- Grapefruit seeds 0.55%

Examples of antioxidants are Tocopherol (0.2%) and CO2 extract of rosemary (0.075%).

The advantages of the compositions of the invention are numerous.

Due to their simple formulation, these compositions are natural and healthy and they present less allergen risk. The compositions can be 100% organic. They have a soft feel after application, in comparison with equivalent compositions in terms of ingredients but comprising surfactants, the latter having a tacky or rough feel.

They also have other very interesting properties. The inventor has in fact shown that the activity of the active principles is preserved in the emulsified compositions without surfactant and that the effectiveness of the compositions (without surfactant) is higher than that of the products with surfactants, in equivalent proportion of active ingredients. .

Finally, these compositions are stable. Their stability is ensured by method, in particular and preferably by means of an ultrasonic treatment whose vibration frequency is greater than or equal to 1 MHz, as described in patent WO2010 / 149668. Their stability at room temperature is observed for at least 3 months and up to more than 12 months.

The compositions according to the invention are compositions for topical use usable in humans or animals.

In a particular embodiment, the aqueous solution of the composition is an orange blossom hydrosol and the HV is an apricot kernel oil. An example of such a composition is described in Example 1; this composition can be used as a make-up removing lotion.

Thus, a second subject of the invention relates to the use of a composition according to the invention containing an oil-in-water emulsion based on HV formulated without surfactant as a make-up removing lotion.

FIGURES

Figure 1: Effectiveness of make-up removal of a lotion type oil-in-water emulsion based on HV formulated without surfactant. The photos show the makeup residue on the wiping cotton. Left column: after using an A-TS lotion with surfactant; right column: after using a lotion A without surfactant.

EXAMPLES

Example 1: Characteristics of an oil-in-water emulsion type product comprising vegetable oils and free of surfactant

at. Composition of make-up remover A

Composition A is prepared using the process described in the application

WO2010 / 149668 and defined below:

ingredients Percentage in composition Orange blossom hydrosol 85 Apricot kernel oil 15

An A-TS composition was prepared using the same process and using the same ingredients as for composition A and in the same proportions, with the difference that 1% of Twin 80 is added, as a surfactant .

b. Protocol for measuring the makeup-removing effect of lotions A and A-TS by colorimetry

In order to assess the makeup-removing effect of the proposed lotions, they were applied to the forearms of healthy subjects. The test was carried out as follows:

1) Cleaning the skin and drying (inside of the forearm)

2) Delimitation of 2 measurement zones; one for applying lotion A and the other for applying lotion A-TS.

3) Measurement of the skin color using a Lab colorimeter on the 2 measurement zones (3 repetitions) to calibrate the device.

4) Application of 100 pL of foundation on each of the zones.

5) Wait 5 min then perform a series of measurements (3 repetitions)

6) Application of 1 g of make-up remover on each of the zones (1 g per zone) with a cotton pad (by making 5 passes over the zone with the cotton pad); this cotton is called "cleansing cotton".

7) Light wiping in a single pass with another dry cotton (no product), this one is called "wiping cotton".

8) Realization of a series of measurements (3 repetitions).

The first series of measurements is noted 0, FT the second and DE the third.

For each makeup remover, the percentage P of foundation removed is given by:

p _ s / (Go - I'Ft) ² + ( ^α ο - ^α Γτ) ² + (Go - ^ ft) ² _x iqq (GdF ^- ^ Ft) ² + ( ^a DE ~ ^a F?) ² + GdE ^- ^ Ft) ²

vs. Protocol for measuring the makeup-removing effect of lotions A and A-TS by filtering on cotton photos.

1) A photo of the cotton used for wiping is taken, with a resolution of at least 3-10 ⁹ pixels.

2) The photo is reduced to the exact size of the cotton, which is itself a square (no use of round cottons for example).

3) The image is loaded into a processing software in the form of a three-dimensional matrix so that it is described in the RGB (Red Green Blue) space.

4) A high-pass filter is applied to each of the dimensions, that is to say on each of the three colors of the definition space, so that the “colored spots” of makeup are clearly identified (threshold cut at 35% intensity against the white of the cotton).

5) The percentage P _s of area of stained cotton is then given by:

number of colored pixels

P _s = ----- Z --- 3 ---, ------ X 100 number of pixels in the image

d. Comparison of the effectiveness of lotions A and A-TS

By applying the colorimetric measurement protocol described above, it can be seen that the lotion with surfactant (A-TS) makes it possible to remove 9% of the foundation, while the lotion without surfactant (A) makes it possible to remove 39% of the foundation. face powder.

These results are also visible in Figure 1 which shows a brown coloration of the foundation on the wiping cottons. The coloring is clearly visible on the three left cottons used after removing makeup with the A-TS lotion. On the contrary, the traces are very light or even invisible on the right wiping cottons used after removing makeup with lotion A.

These observations with the naked eye were confirmed by an analytical method consisting in applying filters to determine the intensity of the spots of makeup on the cottons as described previously; this determines a "percentage of fouling" of the wiping cottons. This method makes it possible to describe a fouling percentage of 13.6% for the series of cottons on the left (after A-TS lotion) against 4.2% for the series of cottons on the right (after Lotion A) (with a margin +/- 1% error for each measurement).

These results clearly show that composition A formulated without surfactant makes it possible to remove makeup much more effectively than composition A-TS comprising a surfactant, while these two compositions have the same proportion of active ingredients (HV and hydrosol). A better activity of the active ingredients is therefore observed in a formulation without surfactant compared to the same dose of active ingredients in the presence of surfactant. This observation highlights the fact that a formulation without surfactant allows better bioavailability of the active ingredients.

Claims (10)

1. Composition of oil-in-water emulsion type comprising an aqueous solution and at least one vegetable oil, this composition containing no surfactant. 2. Composition according to claim 1, in which the aqueous solution contains plant extracts. 3. Composition according to claim 2, in which said aqueous solution is a hydrosol, a plant infusion or a fruit water. 4. Composition according to claim 3, in which the aqueous solution is a hydrosol. 5. Composition according to claim 4, in which the hydrosol and the vegetable oil come from the same plant. 6. Composition according to one of the preceding claims, further comprising a gelling agent. 7. Composition according to one of the preceding claims, further comprising a moisturizing agent. 8. Composition according to one of the preceding claims, in which the aqueous solution is an orange blossom hydrosol and the vegetable oil is an apricot kernel oil. 9. Composition according to claim 9 comprising: - 85% orange blossom hydrosol - 15% apricot kernel oil 10. Use of a composition according to one of claims 8 or 9 as a make-up removing lotion.