WO2007012647A1

WO2007012647A1 - Cosmetic composition for dermabrasion

Info

Publication number: WO2007012647A1
Application number: PCT/EP2006/064647
Authority: WO
Inventors: Alexandre-Michel Robert; Ladislas Robert; Gilles Renard
Original assignee: Institut D'evaluation Dermatophysique
Priority date: 2005-07-26
Filing date: 2006-07-25
Publication date: 2007-02-01
Also published as: FR2889058A1; EP1907069A1

Abstract

The invention concerns a cosmetic treatment method for slowing down or treating skin aging and remedy alteration of the skin including a step of dermabrasion of the epidermis using a composition comprising glycerol formal, isopropanol or palmitoleic acid in sufficient amount to eliminate at last 80 % of the epidermis in the treated zone.

Description

COSMETIC COMPOSITION FOR DERMABRASION

The present invention relates to a cosmetic treatment method for slowing down or treating cutaneous aging and for correcting skin alterations comprising a step of epidermal dermabrasion by means of a composition comprising glycerol formal, isopropanol or acid. palmitoleic in sufficient quantity to eliminate at least 80% of the epidemic in the treated area.

The skin may have aesthetic defects or other alterations such as wrinkles, age spots, acne etc. whose correction can be done by dermabrasion. This last therapeutic method can be practiced in two ways: using instruments exerting a mechanical wear, or with the help of chemicals allowing to eliminate the superficial layers of the epidemic.

Chemical dermabrasion can be practiced with products whose effectiveness is at three levels:

Alphahydroxyacids (lactic acid, glycolic etc.) are the least aggressive, their effect is more superficial. They are effective against fine wrinkles and can give a smoother skin. Nevertheless, for deep alterations such as wrinkles, this treatment does not give a significant aesthetic improvement that meets expectations.

Trichloroacetic acid is much more aggressive. It can be used at different concentrations, and its effect is at an average depth. It is likely to act on superficial defects, wrinkles and pigment problems. For this treatment, several applications are necessary in order to obtain visible results. However, for several months after treatment with trichloroacetic acid it is recommended to avoid exposure to the sun. The most energetic agent is phenol, its action is the deepest. Phenol can be effective against deep wrinkles, defects from excessive sun exposure, pre-cancerous changes, acne scars etc. Healing after treatment can take several months. However, this product has harmful effects on the skin. Indeed, after a phenol dermabrasion, the skin can no longer produce pigments, so after its application you must avoid the sun permanently. In addition, after abrasion facilitated by phenol, it takes about a month to find the epidermis, and some of its functions are lost.

These currently available cosmetic treatments can have undesirable side effects, ranging from infection to scar formation or uneven skin color changes.

It was therefore interesting to develop a chemical dermabrasion process with maximum effect with minimal harmfulness.

We have discovered in the context of the present invention a selective effect of the glycerol formal (GF), isopropanol and palmitoleic acid solvents on the dermal-epidermal junction. The application of these molecules and in particular glycerol formai tested at several concentrations allows to selectively cleave the hemidesmosome type junctions that connect the basal layer of keratinocytes to the basal dermoepidermal lamina. This property makes it possible to eliminate at least 80 to 90% of the epidermis and has not shown any harmful side effects.

We also observed a complete regeneration of the epidermis in just a few days.

Description

Thus, in a first aspect, the invention relates to a cosmetic treatment method for slowing down or treating cutaneous aging, in particular for reducing the depth of wrinkles and / or pigment spots or for correcting skin alterations comprising a step of dermabrasion of the epidermis by means of of a composition or solution characterized in that it comprises at least one compound selected from glycerol formal, isopropanol, palmitoleic acid in an amount sufficient to remove at least 80% of the epidermis in the treated area.

Preferably, the amounts of formal glycerol, isopropanol, and palmitoleic acid are adjusted according to the desired result. Indeed, depending on the depth of wrinkles to be removed, the composition or the solution of the invention is applied so as to obtain an elimination ranging from 80% to 90%, or even 95% of the epidemic.

For example, a composition comprising 2 parts by weight of a cosmetic base and 1 part by weight of formal glycerol, isopropanol, or palmitoleic acid can be applied. The concentration of abrasive compound can be increased as required up to 25%, 50%, 60%, 70% or 75% by weight of the composition, for example from 25% to 50%, or from 50% to 50% by weight. 75% by weight.

Another alternative is the use of a solution comprising at least 25%, 50%, 60%, 70% or 75% by weight of formal glycerol, isopropanol, or palmitoleic acid.

Preferably, formal glycerol can be used. Formal glycerol means two structures in equilibrium with 5-hydroxy-1,3-dioxone and 4-hydroxymethyl-1,3-dioxone, in a ratio of about 60/40.

In the process described above, the composition or the solution is applied to the zone to be treated for a duration ranging from a few minutes, for example from 3 to 5 minutes to a few hours, for example from 1 to 5 hours, or even the entire night, depending on the problems to be treated.

The cosmetic treatment method mentioned above may also comprise a mechanical action on the epidermis, in particular by peeling the skin with an abrasive surface such as a blade. Various examples of mechanical means are described in WO 03/084413, WO 02/053046, EP 1219254. The mechanical microdermabrasion is also illustrated in the documents WO 01/95816, WO 00/67692, in particular by the projection of a liquid (US 5562643). Among the so-called mechanical means, one can also consider the use of ultrasound-based devices (WO 00/15300) or a laser.

The cosmetic treatment method mentioned above may further comprise a step of applying to the skin before and / or after the abrasion step, a solution or composition comprising a locally acting compound decreasing the sensation of pain in the skin. treated area.

The cosmetic treatment method mentioned above may further comprise a step of applying to the skin after the abrasion step a solution or composition stimulating the production of a new dermis dermis from the dermis. This composition may be in the form of a cream or lotion comprising active ingredients for the regeneration of the superficial layer of the skin, especially amino acids, proteins, vitamins, lipids and / or trace elements. It is also possible to apply a composition to protect the skin from the harmful effects of the sun such as sunscreens alone or in combination, especially UV filters, in particular titanium oxides and zinc oxides.

This composition can be applied by means of a gauze or a dressing or a patch maintained on the treated area.

In a second aspect, the invention relates to a dermoabrasive cosmetic composition characterized in that it comprises at least one compound selected from glycerol formal, isopropanol, palmitoleic acid in an amount sufficient to remove at least 80% of the epidemic in the treated area.

The amounts of formal glycerol, isopropanol, and palmitoleic acid are adjusted according to the desired result. By way of example, the composition of the invention comprises at least 25%, 50% or 75% by weight of the compound or compounds Formal glycerol, isopropanol, palmitoleic acid or a mixture thereof allowing for an elimination ranging from 80% to 95% of the epidemic.

For example, a composition comprising 2 parts by weight of a cosmetic base and 1 part by weight of formal glycerol, isopropanol, or palmitoleic acid can be applied. The concentration of abrasive compound may be increased as required up to 50%, 60% or even 70% by weight of the composition.

The composition mentioned above may be in the form of a solution comprising at least 25%, 50%, 60%, 70% or 75% by weight of formal glycerol, isopropanol or palmitoleic acid.

Preferably, formal glycerol can be used.

The invention also relates to a two-in-one product comprising a composition defined above and a cosmetic composition, which may be in the form of a cream or lotion, comprising active ingredients that make it possible to accelerate the regeneration of the surface layer of the skin. skin, especially amino acids, proteins, vitamins, lipids and / or trace elements and / or anti-UV agents.

In a third aspect, the invention relates to the cosmetic use of an abrasive compound selected from glycerol formal, isopropanol, palmitoleic acid to remove at least 80% of the epideπne in a treated area. The invention thus aims at the cosmetic use of said compounds for slowing down or treating cutaneous aging, in particular for reducing the depth of wrinkles and / or pigment spots or for correcting alterations of the skin.

The compositions of the invention can be used directly in the person to be treated or in beauty institutes.

We will refer to the legends below for the rest of the description. legends

Figure 1: Control skin, hematoxylin-eosin staining, G = 360x

The cut passes at the level of a fold, and shows the epidemic and the stratum corneum. Figure 2: Control skin. Hematoxylin-eosin staining, G = I 6Ox

We see the stratum corneum partially abraded.

Figure 3: Skin treated by GF. Hematoxylin-eosin staining, G = 80x.

This section shows the transition zone between the part of the unscratched skin (left of the cup) where the epidemic persists, and then the scraped part, where the epidemic is abraded.

Figure 4: Skin treated by GF. Hematoxylin-eosin staining, G = 80x.

The cut shows the part of the treated skin scraped off by the scalpel. We note the total absence of the epidemic.

Figure 5: Skin treated by GF. Hematoxylin-eosin staining, G = 80x. In places, in the part scraped by the scalpel there are some cell layers of the epidermis (possible nuclei regeneration).

Figure 6: Histological section of an abraded skin after action of glycerol formai, one week after the intervention. Hematoxylin staining - eosie, G = 320x

Figure 7: Histological section of an abraded skin after action of formal glycerol, two weeks after the procedure. Hematoxylin staining - eosie, G = 320x

Example 1 Efficacy Tests of the Compositions of the Invention Described Above

To test the effect of GF and other solvents, we used human skin, obtained from the Aesthetic and Restorative Surgery Service. For the first two experiments we used a mammary skin of a 62-year-old woman, resected during a mammoplasty procedure.

The GF we tried was used at three different concentrations: - Incorporated into a cream base (Biobase of Bioderma) in the proportion of one part of GF for two parts of cream base;

- Incorporated into cream base with equal parts (1: 1)

- In its pure state (in the form of a viscous liquid)

Operating mode

The skin was freed from its subcutaneous fat layer and 8 samples of about 4-5 cm2 were fixed with the epidermis upwards on a plastic mat with pins to reproduce the natural tension of the skin.

treatments

Two samples were used as controls: the first was covered with the base of cream alone (no active ingredient), the second was covered with saline.

Two samples were coated with Preparation No. 1 (base / GF 2: 1)

Two samples were coated with Preparation 2 (base / GF 1: 1)

Two samples were coated with pure GF (Preparation 3)

The duration of action was 30 minutes in the first and one hour in the second experiment. At the end the products were wiped skin samples.

Efficiency test

Each sample was scalpel scraped at a rate and intensity equal for all samples, for a uniform duration for each sample: three minutes in the first and two minutes in the second experiment. At the end of the scratching each sample was photographed. Results

Inspection of skin samples

The inspection of the samples at the end of the scratching showed that the control samples kept almost the entire dermis, despite the scraping. We only see a few incisions due to the scalpel and the intensity of scratching. These incisions remained more visible on the control skin treated with the cream base than on the one having received the saline solution. Indeed, the cream base had to soften the skin a little.

There is a clear difference between the control skin and that treated with the preparation No. 1 (base / GF 2: 1): in all skin samples treated with this preparation the vast majority of the epidemic is eliminated by scraping . With regard to the four samples treated with Preparation No. 2 (base / GF 1: 1), the elimination of the epidermis is almost complete.

The same goes for samples treated with pure GF: there is practically no skin left after scraping.

Example 2: Observation of the results with an optical microscope

An experiment was performed on white skin with a control sample coated with cream base and a treated sample coated with 1: 1 base / GF preparation (preparation # 2). The duration of action was one hour. At the end of this period the two samples were subjected to intense scratching with a scalpel for a period of 2 minutes.

Both samples were stretched on cork supports and pinned to prevent strong retraction during histological treatment. Then the samples were fixed with Bouin's liquid, included in paraplast and cut at 5 μ. The sections were mounted 2 by 2 on slides, dewaxed and stained with haematoxylin and eosin. The skin sections thus prepared were then observed under an optical microscope (Zeiss) and photographed. Three enlargement ratios were used: 8Ox, 16Ox and 32Ox. With the lowest ratio, the entire section can be easily traversed, with the strongest details, such as the successive layers of the epidermis, or the nature of the contact between the epidermis and the underlying dermis. The results of these observations are as follows:

Sample skin cuts

The cuts fold at both ends, only about half the length is approximately straight. The epidermis is clearly visible over most of the length of the section, including the stratum corneum (Fig.l.). Around the middle of the cut, about a quarter of the length, a partial abrasion of the epidemic is visible (Fig.2.). On some parts the stratum corneum alone is absent, in other places almost the entire epidemic is removed. These phenomena are observed towards the middle of the skin samples where the scratching was the most intense. On the other hand, a good adhesion of the epidermis to the dermis, with the exception of the middle of the cut, is found practically throughout the entire length of the section, where scraping with the scalpel resulted in incisions and a disruption of the structure of the cut. dermis.

Treated skin sections

On the sections of the skin treated with the preparation containing GF, the epidemic is preserved only on the edges of the sample which have not been touched by the scalpel (Fig.3). Everywhere else the epidermis is almost completely abraded (Fig.4). However, especially with high magnification, a small amount of epidermis is observed in places, which has not been removed (Fig. 5.). These "islands of resistance" with a thickness of only a few cell layers, are at the origin of a regeneration of a new epidemic. In addition, at high magnification, there is a space between the epidemic and the underlying half. It is clear from the observation of these sections, that on the skin sample treated with the preparation containing the GF, scraping with the scalpel removed almost the entire epidermis over the entire treated skin surface. These results are summarized in Table I below. Table I. Thickness of the epidermis before and after dermabrasion

We measured on the histological sections the thickness of the epidemic. The results obtained, expressed in mm, appear in the following table.

The same day of dermabrasion with use of the product the epidemic is completely absent. One week after the epidermis is reconstituted with a thickness slightly higher than controls, then gradually the thickness of the epidermis returns to normal.

Conclusion

From these two experiences we can draw the following conclusions:

Neither in control nor treated skin did the differences in contact time (30 minutes or 1 hour) nor the duration of scraping (3 minutes or 2 minutes) lead to perceptible changes in the inspection of the skin. skin samples.

The epidermis of the control skin is resistant to scratching on almost the entire surface of the sample. It is only under the microscope that regions appear in the middle of the sample, from which the epidermis is partially or almost completely removed.

The application of pure GF (preparation No. 3) or in the cream base with equal parts (preparation No. 2) has eliminated almost the entire epidermis. At the inspection macroscopically these two products give equivalent results. The application of product No. 1 (base / GF 2: 1) is slightly less effective than the other two, but nevertheless allows at least 80 - 90% of the epidermis to be removed.

Microscopic observation of treated skin sections shows the presence of a few places where part of the epidermis remains. These incompletely abraded parts of the epidermis may be responsible for the regeneration of the epidermis.

Microscopic observation of the control sections showed that the epidermis is almost completely preserved. It is only towards the middle of the skin samples, where the scratching with the scalpel is the most intense, that the epidemic is partially or almost completely removed.

Example 3 Study of the Regeneration of the Abraded Epidermis

The objective of this study was to determine whether normal skin regrowth after the application of the composition according to the invention. The experiments were carried out on hairless rats according to the following protocol: 5 female hairless rats of 170 g initial weight, maintained at constant temperature, with food and drink at will, were treated after general anesthesia with a cream containing 50% glycerolformal in a Bioderma cream base. This cream was applied to the right side of the rats and allowed to act for 30 minutes. Dermabrasion was then performed by scraping with a scalpel for one minute from both flanks of the rats, the left having not received the product and serving as a control.

The two flanks of the rats were photographed, then a rat was sacrificed and skin samples were taken, including:

- intact normal skin, - abraded skin without product,

- abraded skin after action of the cream containing the active ingredient. We let the other rats wake up and we put them back in the pet shop.

One week after the operation, a second rat is sacrificed, then two weeks after a third. The flanks are photographed and skin samples are taken from both flanks, controls and treated.

Skin samples were fixed in Bouin's solution, then included in paraplast and cut at 5 μ. The sections were stained with hematoxylin eosin, then observed and photographed on a Zeiss laboratory photomicroscope.

Results

The results obtained, which will be presented in the figures below, show that from the first week after dermabrasion normal skin has grown back. This was verified two weeks and four weeks after the procedure, and as the photographs show (Figures 6 and 7), the skin that has regrown has all the characteristics of normal skin, both histologically and the macroscopic plane (Table II).

Table II: Basis of comparison - intact skin of a hairless rat

Conclusion

We followed up the regrowth of the epidermis after abrasion facilitated by the products of the invention. Indeed, depending on the toxicity of the product used, the recovery time and the functional value of the regenerated epidemic may vary.

Our observations have shown that in a week's time after the dermabrasion facilitated by the composition of the invention, there is a complete and lasting regeneration of the epidemic, giving the skin a perfectly normal appearance. This shows the non-toxicity or at least the very low toxicity of the product used.

Dermabrasion with glycerolformal completely eliminates the epidemic while preserving the integrity of the basal lamina and the half. Regeneration of the epidemic is rapid. Already one week after surgery, an almost normal epidermis is recovered with its stratum corneum, and at two weeks the quality of the regenerated epidermis after dermabrasion can no longer be distinguished from an unabsorbed skin.

Claims

1. A cosmetic treatment method for slowing down or treating cutaneous aging, in particular for reducing the depth of wrinkles and / or pigment spots or for correcting skin alterations, comprising a step of dermabrasion of the epidermis by means of a composition or solution characterized in that it comprises at least one compound selected from glycerol formal, isopropanol, palmitoleic acid in an amount sufficient to remove at least 80% of the epidermis in the treated area.

2. Method according to claim 1, characterized in that the composition or the solution comprises at least 25%, 50%, or 75% by weight of glycerol formal, isopropanol, palmitoleic acid or their mixture allowing a removal of up to 80% 95% of the epidemic.

3. Method according to claim 1 or 2, characterized in that the composition or the solution comprises formal glycerol.

4. Method according to one of claims 1 to 3, characterized in that the composition or the solution is applied to the area to be treated for a period ranging from a few minutes to a few hours.

5. Method according to one of claims 1 to 4, characterized in that it further comprises a mechanical action on the epidemic, in particular by effleurage of the skin with an abrasive surface, for example a blade, by the projection of a liquid, or by means of an ultrasound or laser device.

6. Method according to one of claims 1 to 5, characterized in that it further comprises a step of applying to the skin before and / or after the abrasion step, a solution or composition comprising an active compound decreasing the sensation of pain in the treated area.

7. Method according to one of claims 1 to 6, characterized in that it further comprises a step of applying to the skin after the abrasion step a solution or composition stimulating the production of a new epidermis from of the denue, said composition being in the form of a cream or lotion comprising active principles for the regeneration of the superficial layer of the skin, especially amino acids, proteins, vitamins, lipids and / or trace elements and / or UV filters.

8. Dermoabrasive cosmetic composition characterized in that it comprises at least one compound selected from glycerol formal, isopropanol, palmitoleic acid in an amount sufficient to remove at least 80% of the epidermis in the treated area.

9. Composition according to claim 8 comprising at least 25%, 50%, or 75% by weight of the abrasive compound allowing an elimination ranging from 80% to 95% of the epidemic.

10. Composition according to claim 8 comprising 2 parts by weight of a cosmetic base and 1 part by weight of formal glycerol, isopropanol, or palmitoleic acid.

11. A composition according to claim 8 being in the form of a solution comprising at least 25%, 50% or 75% by weight of formal glycerol, isopropanol, or palmitoleic acid.

12. Composition according to one of claims 8 to 11 comprising glycerol foπnal.

13. Product two in one comprising a composition defined according to one of claims 8 to 12 and a cosmetic composition, which may be in the form of a cream or lotion, comprising active ingredients for the regeneration of the surface layer of the skin, including amino acids, proteins, vitamins, lipids, trace elements and / or anti-UV agents.

14. Cosmetic use of a compound selected from glycerol formal, isopropanol, palmitoleic acid to remove at least 80% of the epidemic in a treated area.

15. Use according to claim 14 for slowing down or treating skin aging, in particular for reducing the depth of wrinkles and / or pigment spots or for correcting skin changes.