FR3136675A1 - Iontophoretic process for administering an active ingredient - Google Patents

Abstract

The invention relates to a cosmetic and non-therapeutic iontophoretic process for delivering a cosmetic active ingredient through the skin, a cosmetic composition suitable for an iontophoretic process comprising a cosmetic active ingredient and an iontophoretic kit comprising said composition. No abstract figure

Description

Iontophoretic process for administering an active ingredient TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of skin care.

Iontophoresis is an active technique which improves the passage of certain molecules into or through the skin using a low electric current (<1mA). An iontophoretic device consists of a power source and at least two electrodes. One electrode is active, as the current entry point, the other is passive, as the current exit point. One electrode is then the anode, preferentially connected to the positive pole, while the other is the cathode, preferentially connected to the negative pole. The main mechanisms of iontophoresis are:

• Electro-migration or electro-repulsion: the electric current causes the ions to migrate according to their charge. A positively charged molecule in a formulation placed under the anode (+) will be repelled towards the skin and will be attracted to the electrode (-). On the contrary, a negatively charged molecule in a formulation placed under the cathode (-) will be repelled towards the skin and will be attracted by the electrode (+);
• Electro-osmosis or convective transport: allows the transport of molecules thanks to the movements of the solvent from the anode towards the skin and from the skin towards the cathode. This flow is possible thanks to the negative charges of the skin at physiological pH

Many active molecules in skin care compositions are in ionic form, therefore iontophoresis can be an effective tool for the delivery of these active molecules.

It is necessary to develop a stable and adaptable cosmetic formulation with any type of ionizable active ingredient of interest and effectiveness to facilitate their penetration into the skin.

It was surprisingly discovered that such a formulation can be based on the combination of two gums: the gum of Caesalpina spinosa (tara gum or Peruvian locust bean) and the gum of Sclerotium rolfsii .

Tara gum is naturally derived from the endosperm of the seed of the tara tree ( Caesalpinia spinosa ) which grows in the Peruvian Andes.

Sclerotium gum is a water-soluble polysaccharide obtained through the fermentation process of a filamentous fungus known as Sclerotium rolfsii .

FIGURES

: diagram of an iontophoresis device according to one embodiment

: diagram of an iontophoresis device according to another embodiment

: discontinuous current density waveform for iontophoresis

: diagram of the principle of iontophoretic transport

: photographs of the electrodes used in the examples (left: flexible electrodes, right: V2 tip)

: photography of the montage

: annotated photograph of the comparison montage of the broadcast

: comparison diagram of the cutaneous diffusion of the mandelic acid contained in gel C of example 1

comparison diagram of the cutaneous diffusion of ferulic acid contained in gel D of example 2

: comparison diagram of the cutaneous diffusion of the mandelic acid contained in the three formulas studied in Example 3

: comparison diagram of the cutaneous diffusion of the mandelic acid contained in the formulas studied in Example 4

DETAILED DESCRIPTION OF THE INVENTION Non-therapeutic cosmetic process

A first subject of the invention relates to a cosmetic and non-therapeutic iontophoretic process for delivering a cosmetic active ingredient into the skin, comprising:

• Apply to the skin a composition comprising a cosmetic active ingredient, Caesalpinia spinosa gum (tara gum or Peruvian locust bean), Sclerotium rolfssii gum and one or more cosmetically acceptable additives;
• Apply simultaneously, successively or sequentially over a certain time range a direct, pulsed current or a combination of the two from a device comprising at least one electrode applied to the skin, so as to improve the transport of the cosmetic active ingredient through skin.

The process which is the subject of the invention may use a composition comprising a cosmetic active ingredient, Caesalpinia spinosa gum (tara gum or Peruvian locust bean), Sclerotium rolfssii gum and one or more cosmetically acceptable additives as defined. below.

The method according to the invention can be applied to any biological subject, in particular mammals, preferably human beings.

Fluent

The current applied must not cause discomfort, risk of injury or side effects to the user. It is therefore necessary to ensure that the strength of the current and the shape of the electrical wave are bearable throughout the duration of the treatment. In certain cases, a discontinuous current can help avoid the risk of discomfort.

In certain embodiments of the iontophoresis process, the applied current is preferably continuous, with an average current density of 0.001 mA/cm ² to 0.5 mA/cm ² , preferably of 0.01 mA/cm ² to 0.4 mA/cm ² , and more preferably from 0.05 mA/cm ² to 0.3 mA/cm ² .

In certain embodiments of the iontophoresis process, the applied current is preferably discontinuous, with an average current density of 0.001 mA/cm ² to 0.5 mA/cm ² , preferably of 0.01 mA/cm ² to 0.4 mA/cm ² , more preferably from 0.05 mA/cm ² to 0.3 mA/cm ² and particularly preferably from 0.13 mA/cm² to 0.45 mA/cm².

In certain embodiments of the iontophoresis process, the applied current is discontinuous with an average current density of 0.001 mA/cm ² to 0.5 mA/cm ² , preferably 0.01 mA/cm ² to 0, 4 mA/cm ² , and more preferably from 0.05 mA/cm ² to 0.3 mA/cm ² .

Preferably, the average intensity of the current is between 0.001 mA and 0.5 mA and is for example of the order of 0.1 mA.

In some embodiments of the iontophoresis method, direct current and discontinuous current are applied in combination, preferably with the above current densities.

“Discontinuous current” or “pulsed current” means a current whose intensity varies over time.

By direct current we mean a current whose intensity does not vary over time, that is to say that the intensity is constant and is independent of time.

In some embodiments of the iontophoresis method, the applied discontinuous current has sinusoidal waveforms, non-sinusoidal waveforms, or combinations thereof.

In some embodiments of the iontophoresis method, the discontinuous current applied has periodic square waveforms, rectangular waveforms, sawtooth waveforms, spike waveforms, trapezoidal waveforms, triangular waveforms, or combinations thereof.

Preferably, the discontinuous current applied has rectangular waveforms, advantageously with an average intensity of 0.001 mA/cm ² to 0.5 mA/cm ² , preferably of 0.01 mA/cm ² to 0.4 mA/ cm ² , and more preferably from 0.05 mA/cm ² to 0.3 mA/cm ² .

In some embodiments of the iontophoresis method, the current is applied for 30 seconds to 120 minutes, preferably 2 minutes to 50 minutes and more preferably 3 minutes to 40 minutes.

In some embodiments, the direct current stimulus may be applied for a duration of 2, 5, 10 or 20 minutes.

There illustrates an embodiment of electrical stimuli of a representative current density waveform generated by the circuitry of the iontophoresis device.

Referring to the , a first current density waveform is shown for iontophoresis. There illustrates an embodiment of a waveform that can be generated by the circuit and the iontophoresis device of the or 2.

There illustrates a discontinuous current waveform stimulus having a rectangular wave profile. The average intensity of this current is of the order of 0.1 mA. The maximum intensity of this current is of the order of 0.2 mA. Each 0.2 mA current pulse is applied for approximately 40 ms, then no current is applied for another 40 ms period, and so on. The current frequency is around 12.5 Hz.

The current density and duration values shown in the are given as an example and are not restrictive.

Cosmetic composition suitable for iontophoresis

A second object of the invention relates to a cosmetic composition suitable for an iontophoretic process comprising a cosmetic active ingredient, Caesalpinia spinosa gum (tara gum or Peruvian locust bean), Sclerotium rolfssii gum and one or more cosmetically acceptable additives .

Assets

Due to their non-ionic property, these gums are resistant to variations in pH, to the presence of electrolytes and benefit from good skin tolerance.

Beyond the physicochemical properties specific to these gums and their compatibility with iontophoresis technology, their combination allows obtaining a unique sensoriality and is directly applicable for the development of serum-type products.

Advantageously, the active ingredient is chosen from the group consisting of ferulic acid, mandelic acid, vitamin C and its derivatives, adenosine, niacinamide, acetyl tetrapeptide-2, acetyl tetrapeptide-5, acetyl tetrapeptide-11, acetyl tetrapeptide-9, acetyl hexapeptide-8, trifluoroacetyl tripeptide-2, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, dipeptide diaminobutyroyl benzylamide diacetate, decarboxy carnosine HCL, dipotassium glycyrrhizate, L-pyrrolidone carboxylic acid, hyaluronic acid and combinations thereof.

Advantageously, the active ingredient is present in a proportion ranging from 0.001 to 25.0% by weight, preferably 0.1 to 10.0% by weight, more preferably 0.3% to 2.0%. in weight relative to the total weight of the composition.

Additives

The composition may further comprise one or more polar solvent(s), preferably present in an amount of at least 30% by weight, preferably in an amount of at least 40% by weight, and more preferably in an amount of at least 50% by weight, relative to the total weight of the composition.

The composition may further comprise one or more anionic or nonionic polymers present in quantities ranging from 0.01% to 30% by weight relative to the total weight of the composition, preferably from 0.1% to 10% by weight, relative to the total weight of the composition.

The composition may further comprise xanthan gum.

Advantageously, the composition comprises from 0.3 to 3.0% by weight relative to the total weight of the composition, preferably 0.4 to 1.0% by weight relative to the total weight of the Caesalpinia spinosa gum composition ( tara gum or carob from Peru).

Advantageously, the composition comprises from 0.2 to 1.3% by weight relative to the total weight of the composition, preferably 0.3 to 0.8% by weight relative to the total weight of the composition of Sclerotium gum. rolfssii .

Advantageously, the composition comprises a ratio of Caesalpinia spinosa gum (tara gum or Peruvian locust bean): Sclerotium rolfssii gum by weight of between 1:5 and 5:1, preferably between 1:2 and 2:1.

The composition may comprise water present in an amount of at least 30% by weight relative to the total weight of the composition, in particular in an amount of at least 60% by weight, and more preferably in an amount of at least 80% by weight relative to the total weight of the composition.

The composition is, for example, free of any ionizable preservative.

In known manner, the dosage forms dedicated to topical administration can also contain conventional adjuvants in the cosmetic and/or dermatological field.

Galenic

Such a composition may be in the form of an aqueous, hydroalcoholic solution, a solution or dispersion of lotion or serum type, an emulsion of liquid or semi-liquid consistency of milk type, obtained by dispersing a fatty phase in an aqueous phase (OAV) or vice versa (W/O), or a suspension, or emulsion, of soft, semi-solid or solid consistency, of the cream, aqueous or anhydrous gel type, a microemulsion, a microcapsule, a microparticle, or a vesicular dispersion of ionic and/or non-ionic type.

These compositions are prepared according to the usual methods.

Route of administration

A composition according to the invention is advantageously administered topically to the skin.

It can be used for cosmetic and/or dermatological treatment of the skin.

Iontophoresis kit

The invention also provides an iontophoresis kit comprising:

• Cosmetic composition suitable for an iontophoretic process comprising a cosmetic active ingredient, Caesalpinia spinosa gum (tara gum or Peruvian locust bean), Sclerotium rolfssii gum and one or more cosmetically acceptable additives, and
• An iontophoretic device for implementing the method as described above.

The iontophoresis composition may be as described above.

The selected current profile may be as described above in relation to the method.

In certain embodiments, the kit according to the invention is in the form of a tube (or container) comprising the cosmetic composition according to the invention and an electronic cap comprising said iontophoretic device to implement the method as described above.

Iontophoretic device

In reference to the , an iontophoresis device 1 and a set of electrodes 41, 42, 43 are illustrated schematically. In this embodiment, the iontophoresis device 1 comprises an electronic plug 4 advantageously connected to a tube 2, containing a cosmetic composition, in particular such as that described above. The electronic plug 4 is preferably assembled on the tube 2 in a reversible manner, in particular by screwing. This allows the user to easily change the tube 2, and therefore to change composition and cosmetic treatment, while retaining a single electronic cap 4. For example, the user could thus have in his possession a single cap electronic 4 and different tubes 2, for example a first tube with the composition comprising a cosmetic active principle, Caesalpinia spinosa gum (tara gum or Peruvian locust bean), Sclerotium rolfssii gum and one or more defined cosmetically acceptable additives previously, a second tube with another composition suitable for iontophoretic use, etc. It will then be possible and easy for the user to alternate between the different cosmetic compositions in order to benefit from different cosmetic treatments on the skin.

By electronic plug 4 is meant any electronic and/or electrical and/or electromechanical device capable of generating a current, in particular a current such as that described above and illustrated in . The electronic cap 4 is designed to be placed in contact with the user's skin during treatment, in particular via the electrodes 41, 42, 43. Preferably, the electronic cap 4 is designed to be mounted in a reversible manner, in particular by screwing, onto the tube 2 containing the cosmetic composition.

According to another embodiment of the iontophoretic device 1 illustrated in , the device further comprises a cannula 3, arranged between the electronic plug 4 and the tube 2. This cannula 3 is designed to, on the one hand, be mounted on the tube 2 preferably in a reversible manner, for example by screwing, and on the other hand, cross the electronic plug 4, as can be seen in the . The cannula 3 can be designed to cooperate with the electronic cap according to the principle of a pivot connection. This cannula 3 then makes it possible to convey the cosmetic composition from tube 2 to the user's skin without coming into contact with the electronic cap 4, thus preserving the electronic components of the latter, improving hygiene and facilitating cleaning. of the last.

According to one embodiment, the iontophoretic device 1 is produced in accordance with that described in the patent application filed by the applicant under the filing number FR2200962.

Whatever the embodiment of the iontophoretic device 1, the electronic plug 4 notably comprises a power source (not illustrated), such as a cell or a rechargeable battery, a current waveform generator (not illustrated ), a first (active) electrode 41, a second electrode (counter or return) 42. The device can also include other electrodes and other elements (such as a light-emitting diode for example) without departing from the scope of the invention .

In the illustrated embodiments, the electronic cap also includes an orifice 44 designed to deliver the cosmetic composition to the user's skin, in particular following the pressure that the user will exert on the tube 2 during the treatment.

In the embodiment where the electronic cap 2 comprises a cannula 3 ( ), the latter is connected in a sealed manner to the orifice 44, so that the cosmetic composition contained in the tube 2 is delivered directly to the skin of the user, passing through the electronic cap 2 without however coming into contact internal components (in particular electronic and/or electrical) of the latter.

The purpose of Figures 1 and 2 is to illustrate and describe some of the main functional components of an iontophoresis device used to carry out one or more of the various embodiments of the methods described herein.

The circuits used to perform the functions of the iontophoresis device are implicit, inherent and well known to those skilled in the art so that they will not be described in further detail here.

In certain embodiments, the iontophoresis device is packaged in the form of a manual device which can be carried in one hand during treatment, as is particularly the case with the embodiments illustrated in Figures 1 and 2 Treatment with a handheld device includes constantly moving the iontophoresis device over the skin such that at least the active electrode 41 is moved over the skin surface while making contact. Preferably it is the electronic cap 4 and tube 2 assembly, that is to say the entire iontophoretic device 1, which is moved by the user on his skin, as the iontophoretic treatment progresses. We could also imagine, without departing from the scope of the invention, that the iontophoretic device 1 is moved by a first user on the skin of a third party user, for example in the case of a cosmetic treatment carried out in a beauty institute. .

A suitable power source is any power source capable of generating electrical current to power the various other circuits and devices. In certain embodiments, a battery, preferably rechargeable, is used as a power source. In some embodiments, the iontophoresis device is plugged into a wall outlet. In some embodiments, the power source produces direct current.

In some embodiments, an iontophoresis device includes an iontophoresis patch model. By iontophoresis patch we mean any device intended to be applied to a specific area of the skin and to remain immobile there for at least a certain time in order to carry out localized and continuous iontophoresis treatment. In an illustrative and non-limiting manner, the patch could be produced such as that described in the applicant's patent published under the number FR 3 035 792 and/or FR 3 034 017.

In some embodiments, an iontophoresis device includes an iontophoresis face mask design. By facial mask we mean any device intended to be applied to a large area of the skin, such as the forehead and/or cheeks, around the eyes, the neck, and to remain immobile there for at least a certain time so as to to carry out a continuous iontophoresis treatment over the entire said area. By way of illustration and not limitation, the patch could be produced such as that described in the applicant's patent application published under number WO 2017/212343.

Cosmetic applications

Preferably, the active ingredient is chosen from the group consisting of ferulic acid, mandelic acid, vitamin C and its derivatives, adenosine, niacinamide, acetyl tetrapeptide-2, acetyl tetrapeptide-5, acetyl tetrapeptide-11, acetyl tetrapeptide-9, acetyl hexapeptide-8, trifluoroacetyl tripeptide-2, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, dipeptide diaminobutyroyl benzylamide diacetate, decarboxy carnosine HCL, dipotassium glycyrrhizate, L-pyrrolidone carboxylic acid, hyaluronic acid and combinations thereof.

In a preferred embodiment, the above method makes it possible to reduce spots on the hands and/or on the face and/or on the neck and/or décolleté, for example age spots and/or sun spots. and/or freckles and/or spots due to disease. Then, the above method allows depigmentation of the skin, especially in areas where the pigmentation is initially too high. After several uses or a single use of the method of the invention, the color of the skin is more uniform and the homogeneity is increased.

In another embodiment, the method is used to treat signs of aging, to improve skin smoothness, skin quality and appearance.

In another embodiment, the method is used to minimize signs of skin aging, and/or pigmentation, and/or volume, and/or sagging of wrinkles, and/or tone and/or wrinkles. spots, and/or to improve the firmness, and/or radiance, and/or smoothness of the skin. The method of the invention can be associated with the application of active agents associated with an electric current, in particular a microcurrent).

The cosmetic applications of the active ingredients listed above are summarized in the following table:

Assets Cosmetic application Ferulic acid Anti-aging (anti-oxidant) Mandelic acid Anti stain Vitamin C and its derivatives Anti-aging, Radiance, Anti-stain Adenosine Anti-aging, anti-inflammatory Niacinamide Anti-aging, Radiance, Hydration, Anti-stain acetyl tetrapeptide-2 Anti-aging Acetyl tetrapeptide-5 Anti-puffiness, Concealer Acetyl tetrapeptide–11 Anti-aging Acetyl tetrapeptide-9 Anti-aging Acetyl hexapeptide-8 Anti-aging Trifluoroacetyl tripeptide-2 Anti-aging Palmitoyl tripeptide-1 Anti-aging Palmitoyl tetrapeptide-7 Anti-aging Dipeptide diaminobutyroyl benzylamide Diacetate Anti-aging Decarboxy carnosine HCL Anti-aging Dipotassium glycyrrhizate Hydration, anti-inflammatory L-pyrrolidone carboxylic acid Hydration Hyaluronic acid Anti-aging, hydration, plumping

EXAMPLES Material and method

Depending on the studies carried out, different types of electrodes are used as presented below.

Soft electrodes

Flexible electrodes (Ag/AgCl coated with carbon) are used as part of the study in static mode (see ).

For viscous formulations, the deposits are applied directly to the electrodes using a mold.

For low viscosity formulations, the deposits are made on a non-woven support previously fixed on the electrodes using an adhesive film.

Stainless steel electrodes integrated into an applicator tip

These electrodes are used as part of the study in dynamic mode, that is to say, a circular movement of the tip is made on the skin covered with the formula studied.

The use of stainless steel electrodes in dynamic mode makes it possible to get closer to the final use of the product by the consumer. This makes it possible to validate the proof of concept of the association of the tips with the asset. The V2 tip is used (see ).

The detailed description of the different electrodes used is presented below.

Soft electrodes V2 tip Electrodes Parallel electrodes (Ag/AgCl) covered with carbon (3 cm²), covered with a non-woven 2 parallel active stainless steel electrodes (0.653 cm²)
+
a neutral electrode for a massage/stability role Food Connected to electronic bench Connected to electronic bench Fluent 600 µA continuous 330 µA tube wave V2
Current density 200 µA/cm² 443 µA/cm²

Diffusion cells

The diffusion cells include skin explants in a case.

This study is carried out on porcine ear skin explants.

Porcine ear skin has the most similarities with human skin in terms of skin thickness, follicular structure, vascular anatomy and arrangement of collagen fibers.

Example 1: study of the diffusion by iontophoresis of a composition according to the invention comprising mandelic acid (MA)

This study is carried out with flexible electrodes.

The diffusion cells are placed in a water bath at 37°C to obtain a temperature of 32°C on the surface of the skin.

They are connected to a current generator (see ).

In this study, we compare diffusion with cells connected to electrodes (AD) to diffusion with unconnected cells (passive SD diffusion) (see ).

We thus calculate an improvement factor directly linked to iontophoresis which is equal to the average of the concentrations of the active ingredient in the skin for the AD samples divided by the average of the concentrations of the active ingredient in the skin for the SD samples. .

This report indicates the degree of improvement in the skin passage of the active ingredient by iontophoresis (AD) compared to passive application (SD).

The study is carried out under the following experimental conditions.

Type of study Diffusion study on a single formula
Soft electrodes
Static mode Objective The aim of this study is to evaluate the iontophoretic compatibility of gel C in combination with mandelic acid. Mandelic acid concentration of gel C (% w/w) 0.5% Receiving liquid PBS (approximately 20 mL) Skin type Pig ear skin Duration of the treatment 30 minutes Temperature Franz cell: 37°C
Skin: 32°C Cell agitation 1000 rpm Amount of formula applied Approximately 0.700-0.800 g/cell Number of cells 3 SD cells, 4 AD cells and 1 blank (skin) Electrodes Parallel electrodes (Ag/AgCl) covered with carbon (3 cm²), covered with a non-woven Fluent 600 µA continuous Current density 200 µA/cm²

Gel C tested has the following composition.

Ingredients Supplier % in weight Water - Qs 100 Sodium hydroxide 20% - Qsp pH 5.5 Mandelic acid Spec-Chem 0.5 Chlorphenesin BASF 0.3 Pentylene glycol Symrise 0.5 1,2 hexanediol & Caprylyl glycol Symrise 0.5 Glycerin Cooper 2 Sclerotium gum Alban Muller 0.3 Caesalpinia spinosa gum JRS Rettenmaier 0.6

Results

There presents the comparison of the average areas of mandelic acid peaks measured at the cathode of cells with devices (AD -) compared to the average areas of mandelic acid peaks measured in control cells without devices (SD).

The average of the AD – areas is 16.1 times greater than the average of the SD (control) areas. Consequently, iontophoresis makes it possible to very clearly improve the diffusion of the mandelic acid contained in gel C compared to passive diffusion.

Example 2: study of the diffusion by iontophoresis of a composition according to the invention comprising ferulic acid

This study was carried out under conditions similar to example 1.

Type of study Diffusion study on a single formula
Soft electrodes
Static mode Objective The aim of this study is to evaluate the iontophoretic compatibility of gel D in combination with ferulic acid. Ferulic acid concentration of gel D (% w/w) 0.5% Receiving liquid PBS (approximately 20 mL) Skin type Pig ear skin Duration of the treatment 30 minutes Temperature Franz cell: 37°C
Skin: 32°C Cell agitation 1000 rpm Amount of formula applied Approximately 0.77 g/cell Number of cells 3 SD cells, 5 AD cells and 1 blank (skin) Electrodes Parallel electrodes (Ag/AgCl) covered with carbon (3 cm²), covered with a non-woven Fluent 600 µA continuous Current density 200 µA/cm²

Gel D tested has the following composition.

Ingredients Supplier % in weight Water - Qs 100 Sodium hydroxide 10% - Qsp pH 5.5 Ferulic acid Spec-Chem 0.5 Chlorphenesin BASF 0.3 Pentylene glycol Symrise 0.5 1,2 hexanediol & Caprylyl glycol Symrise 0.5 Glycerin Cooper 2 Propanediol Dupont Tate & Lyle organic 10 Sclerotium gum Alban Muller 0.3 Caesalpinia spinosa gum JRS Rettenmaier 0.6

Results

There presents the comparison of the average areas of ferulic acid peaks measured at the cathode of cells with devices (AD -) compared to the average areas of ferulic acid peaks measured in control cells without devices (SD).

The average of the AD – areas is 6.2 times greater than the average of the SD (control) areas. Consequently, iontophoresis makes it possible to very clearly improve the diffusion of the ferulic acid contained in gel D compared to passive diffusion.

Example 3: comparative study of the impact of the formulation on diffusion by iontophoresis

This study is carried out with flexible electrodes.

Its aim is to compare the impact of the chemical nature of the gelling agent(s) on the diffusion of mandelic acid on 3 formulations.

The conductivity of the formulas remains in a similar order of magnitude and does not have an impact at this level on the results obtained.

The study is carried out under the following experimental conditions.

Type of study Soft electrodes
Static mode Mandelic acid concentration of the compositions (% w/w) 0.5% Receiving liquid PBS (approximately 20 mL) Skin type Pig ear skin Duration of the treatment 30 minutes Temperature Franz cell: 37°C
Skin: 32°C Cell agitation 1000 rpm Amount of formula applied Approximately 0.700-0.800 g/cell Number of cells 9 AD cells and 1 white (skin) Electrodes Parallel electrodes (Ag/AgCl) covered with carbon (3 cm²), covered with a non-woven Fluent 600 µA continuous Current density 200 µA/cm²

The following compositions were studied.

Ingredients Supplier Gel A (comparison) Gel B (comparison) Gel C (invention) Water - Qs 100 Qs 100 Qs 100 Sodium hydroxide 20% - Qs pH 5.5 Qs pH 5.5 Qs pH 5.5 Mandelic acid Spec-Chem 0.5 0.5 0.5 Chlorphenesin BASF 0.3 0.3 0.3 Pentylene glycol Symrise 0.5 0.5 0.5 1,2 hexanediol & Caprylyl glycol Symrise 0.5 0.5 0.5 Glycerin Cooper 2 2 2 Sclerotium gum Alban Muller - - 0.3 Caesalpinia spinosa gum JRS Rettenmaier - - 0.6 Xanthan gum JRS Rettenmaier - 0.8 - Sodium polyacrylate starch Kobo Product Inc 0.8 - - Conductivity 3,211 mS/cm 2743mS/cm 2247mS/cm

Results

There presents the comparison of the average of the areas of the mandelic acid peaks measured at the cathode of the cells (AD -) compared to the average of the areas of the mandelic acid peaks measured at the anode of the cells (AD +).

The skin diffusion of the mandelic acid contained in the composition according to the invention is very clearly improved compared to the two other compositions. Indeed, this diffusion is approximately 1.5 times greater compared to gel B and almost 1.9 times greater compared to gel A.

These results demonstrate that the combination of the two gums of Caesalpinia spinosa and Sclerotium rolfssii makes it possible to improve skin penetration by iontophoresis of an active ingredient.

Example 4: effect of iontophoresis on the skin diffusion of mandelic acid with the V2 tip

This study is carried out with the V2 tip. In this study, a reference cream (“Glowing Pen”) is compared to gel C of example 3.

The study is carried out under the following experimental conditions.

Type of study Modes: dynamic AD, passive SD. Formula “Glowing Pen” cream with 0.5% AM
Or
Gel C at 0.5% AM Receiving liquid PBS (approximately 20 ml) Cell temperature Ambient temperature Cell agitation 0 rpm Skin type Pig ear skin Amount of formula applied Approximately 0.200 g/cell Number of cells 6 AD cells (3 AD cream, 3 AD Gel C) and 4 SD cells (2 SD cream, 2 SD Gel C) Treatment duration 30 minutes Electrodes Stainless steel parallels (0.653 cm²)
V2 tip electrodes Fluent 330 µA tube wave V2 Current density 443 µA/cm²

The reference formula tested (“Glowing Pen” cream) has the following composition.

Mixed INCI Name % in weight Lemon water (CITRUS LIMON (LEMON) FRUIT WATER) 72.176700 Citrus unshiu peel extract 5.138815 Squalane 4.000000 Olive oil decyl esters 3.658000 Heliantus annuus (sunflower) seed oil 3.150000 Glyceryl stearate 2.500000 PEG-100 stearate 2.500000 Copolymer of ammonium acryloyldimethyltaurate and vinylpyrrolidone
2.000000 Benzyl alcohol 1.059500 Water 0.641833 Mandelic acid 0.500000 Panthenol 0.500000 Propylene glycol 0.500000 Lilium candidum flower extract 0.350000 Glycerin 0.333500 Squalene 0.300000 Tocopherol 0.202000 Sodium hydroxide 0.181467 Salicylic acid 0.149500 Phenoxyethanol 0.071500 Oleic acid 0.040000 Sorbic acid 0.032500 Potassium sorbate 0.007150 Sodium citrate 0.004950 Citric acid 0.002475 Biotin 0.000110 100.000000

Results

There presents the comparison of the average of the areas of the mandelic acid peaks measured at the cathode of the cells treated with the reference formula (AD Cream) compared to the average of the areas of the mandelic acid peaks measured at the cathode of the cells treated with the gel (AD gel C).

The skin diffusion of the mandelic acid contained in the composition according to the invention is very significantly improved compared to the reference composition. In fact, this diffusion is approximately 2.5 times greater in the case of treatment with gel C.

These results demonstrate that the combination of the two gums of Caesalpinia spinosa and Sclerotium rolfssii makes it possible to improve skin penetration by iontophoresis of an active ingredient.

Claims (22)

Cosmetic and non-therapeutic iontophoretic process for delivering a cosmetic active ingredient through the skin, comprising the following steps:

• Apply to the skin a composition comprising a cosmetic active ingredient, Caesalpinia spinosa gum (tara or Peruvian locust bean gum), Sclerotium rolfssii gum and one or more cosmetically acceptable additives,
• Apply simultaneously, successively or sequentially over a certain time range a direct current, pulsed current or a combination of the two from a device comprising at least one electrode applied to the skin, so as to improve the transport of the cosmetic active ingredient through skin.

A method according to claim 1, wherein a direct current is applied having an average current density of 0.001 mA/cm ² to 0.5 mA/cm ² , preferably 0.01 mA/cm ² to 0.4 mA/ cm ² , and more preferably from 0.05 mA/cm ² to 0.3 mA/cm ² . A method according to claim 1, wherein a discontinuous current is applied having an average current density of 0.001 mA/cm ² to 0.5 mA/cm ² , preferably 0.01 mA/cm ² to 0.4 mA/ cm ² , and more preferably from 0.05 mA/cm ² to 0.3 mA/cm ² . A method according to claim 3, wherein a discontinuous current is applied having an average current density of 0.13 mA/cm² to 0.45 mA/cm². Method according to any one of the preceding claims, in which a direct current is applied for from 30 seconds to 120 minutes, preferably from 2 minutes to 50 minutes and more preferably from 3 minutes to 40 minutes. Process according to any one of the preceding claims, characterized in that the active principle is chosen from the group consisting of ferulic acid, mandelic acid, vitamin C and its derivatives, adenosine, niacinamide, acetyl tetrapeptide-2, acetyl tetrapeptide-5, acetyl tetrapeptide–11, acetyl tetrapeptide-9, acetyl hexapeptide-8, trifluoroacetyl tripeptide-2, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7 , dipeptide diaminobutyroyl benzylamide diacetate, decarboxy carnosine HCL, dipotassium glycyrrhizate, L-pyrrolidone carboxylic acid, hyaluronic acid and combinations thereof. Process according to any one of the preceding claims, said composition comprising 0.001 to 25.0% by weight, preferably 0.1 to 10.0% by weight, more preferably 0.3% to 2.0% by weight. weight of cosmetic active ingredient relative to the total weight of the composition. Process according to any one of the preceding claims, said composition comprising one or more polar solvents. Process according to any one of the preceding claims, said composition comprising from 0.3 to 3.0% by weight, preferably 0.4 to 1.0% by weight of Caesalpinia spinosa gum (tara gum or Peruvian locust bean) by relative to the total weight of the composition. Process according to any one of the preceding claims, said composition comprising from 0.2 to 1.3% by weight, preferably 0.3 to 0.8% by weight of the gum of Sclerotium rolfssii relative to the total weight of the composition. Process according to any one of the preceding claims, said composition comprising a ratio of Caesalpinia spinosa gum (tara gum or Peruvian locust bean): Sclerotium rolfssii gum by weight of between 1:5 and 5:1, preferably between 1: 2 and 2:1. Process according to any one of the preceding claims, said composition comprising at least 30% by weight, preferably at least 60% by weight of water, and more preferably at least 80% by weight of water relative to the weight. total composition. Cosmetic composition suitable for an iontophoretic process comprising a cosmetic active ingredient, Caesalpinia spinosa gum (tara gum or Peruvian locust bean), Sclerotium rolfssii gum and one or more cosmetically acceptable additives. Cosmetic composition according to claim 13, characterized in that the active principle is chosen from the group consisting of ferulic acid, mandelic acid, vitamin C and its derivatives, adenosine, niacinamide, acetyl tetrapeptide- 2, acetyl tetrapeptide-5, acetyl tetrapeptide–11, acetyl tetrapeptide-9, acetyl hexapeptide-8, trifluoroacetyl tripeptide-2, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, dipeptide diaminobutyroyl benzylamide diacetate, decarboxy carnosine HCL, dipotassium glycyrrhizate, L-pyrrolidone carboxylic acid, hyaluronic acid and combinations thereof. Cosmetic composition according to claim 13 or 14, comprising 0.001 to 25.0% by weight, preferably 0.1 to 10.0% by weight, more preferably 0.3% to 2.0% by weight of principle cosmetic active relative to the total weight of the composition. Cosmetic composition according to any one of claims 13 to 15 comprising one or more polar solvents. Cosmetic composition according to any one of claims 13 to 16, said composition comprising from 0.3 to 3.0% by weight, preferably 0.4 to 1.0% by weight of Caesalpinia spinosa gum (tara or carob gum from Peru) relative to the total weight of the composition. Cosmetic composition according to any one of claims 13 to 17, said composition comprising from 0.2 to 1.3% by weight, preferably 0.3 to 0.8% by weight of Sclerotium rolfssii gum relative to the weight total composition. Cosmetic composition according to any one of claims 13 to 18, said composition comprising a ratio of Caesalpinia spinosa gum (tara gum or Peruvian locust bean): Sclerotium rolfssii gum by weight of between 1:5 and 5:1, preferably between 1:2 and 2:1. Cosmetic composition according to any one of claims 13 to 19, said composition comprising at least 30% by weight, preferably at least 60% by weight of water, and more preferably at least 80% by weight of water per relative to the total weight of the composition. Iontophoretic kit including:

• Cosmetic composition suitable for an iontophoretic process comprising a cosmetic active ingredient, Caesalpinia spinosa gum (tara or Peruvian locust bean gum), Sclerotium rolfssii gum and one or more cosmetically acceptable additives, and
• An iontophoretic device for implementing the method according to any one of claims 1 to 12.

Kit according to claim 21, in the form of a tube comprising a container comprising said cosmetic composition and a cap comprising said iontophoretic device for implementing the method according to any one of claims 1 to 12.