EMOLLIENT COSMETIC OR DERMATOLOGICAL COMPOSITION IN THE FORM OF A SPRAY FOR THE TREATMENT OF SUPERFICIAL BURNS, IRRITATIONS OR SEVERE CONDITIONS OF DRYNESS

Abstract

The present invention relates to a composition for topical use in the form of a spray, which advantageously takes the form of a cosmetic or dermatological composition and which comprises at least lanolin or one of its derivatives and at least one antioxidant; which composition can be used for the prevention and / or treatment of conditions of skin dryness, small burns in a subject (superficial burns) or in the treatment and / or reduction of the frequency of eczematous outbreaks observed in a subject suffering from atopic dermatitis.

Description

Title of the invention: EMOLLIENT COSMETIC OR DERMATOLOGICAL COMPOSITION IN THE FORM OF A SPRAY FOR THE TREATMENT OF SUPERFICIAL BURNS, IRRITATIONS OR SEVERE CONDITIONS OF DRYNESS Field of invention

[0001] The present invention relates to the field of treatment of pathologies and conditions associated with an altered skin barrier function. State of the prior art

[0002] The epidermis corresponds to a multi-stratified epithelium, of ectodermal origin, which is in perpetual renewal. Its primary function is to protect the body from dehydration, mechanical stress and also from certain pathogenic attacks.

[0003] As for the cellular composition of this epithelium, it integrates different cell types with mainly keratinocytes (more than 90%), but also includes Langerhans cells, Merkel cells and melanocytes.

[0004] As for the structure of the latter, several layers of different morphological nature and cellular composition can be distinguished. Thus, from the inside to the outside, we find:

[0005] * the basal layer, cellular base of which keratinocytes are the major element with a very strong proliferation capacity which allows them to ensure self-renewal of the epidermis,

[0006] * the suprabasal layers (granular, spinous layers) and, finally,

[0007] * the horny layer (Stratum Comeum, SC).

[0008] One of the fundamental functions of the epidermis and, more generally, of the skin is to provide a barrier between the body and the external environment, which barrier opposes, in one direction, the penetration into the epidermis of fungi, bacteria, viruses or even allergens from the environment and, in the other direction, the loss of water from the body.

[0009] The quality of the barrier function is therefore crucial and is evaluated, in vivo and in humans, by measuring the insensible water loss and the hydration rate and, in mice, by death by dehydration of embryos, skin permeability to a dye or even by the reduction in body weight.

[0010] Now, and as regards the maintenance of a functional epidermal barrier function, the key parameters are multiple and include:

[0011] *the integrity of the extracellular lipid cement

[0012] * The integrity of all cellular components of the stratum corneum

[0013] * the balance between keratinocyte proliferation and differentiation

[0014] * the pH gradient which, by regulating the activities of the different enzymes, will contribute at the equilibrium of the barrier

[0015] * the concentration of calcium ions which, by regulating the secretion of lamellar bodies in the granular layer, will influence the composition of the extracellular cement of the horny layer and thus the balance of the epidermal barrier.

[0016] However, among all these parameters, hydration is clearly the most critical. Within the epidermis, we find a water gradient that ranges from a concentration of 70% in the visible layers of the epidermis to 30% in the lower layers of the Stratum Corneum, or even 15% at the level of the most external cellular layers of the epidermis. It is also very likely that some of the water within the epidermis is retained from the junction between the granular layer and the horny layer.

[0017] As for the stratum corneum, one of the functions of water within it is to enable the enzymatic hydrolysis reactions necessary for the flexibility of the skin and normal desquamation. Thus, if the amount of water present in the Stratum Corneum falls below a critical threshold, these enzymatic reactions will be disrupted, leading to the adhesion of corneocytes and the accumulation of cells on the surface of the skin.

[0018] This hydration of the skin is based on two phenomena. First, the supply of water by the trans-epidermal flow from the blood circulation and then the retention of epidermal water which involves the skin barrier function. Now, and this can be easily understood, the effectiveness of the skin barrier against water loss is not absolute, only due to the necessary circulation between its cells.

[0019] Beyond this normal circulation, the skin barrier function may be altered in the majority of skin pathologies. These irritations or uncomfortable skin reactions can be induced by exogenous stress, of chemical origin (xenobiotics, antigens, allergens, cosmetic products, and more generally any compound likely to cause skin irritation), of environmental origin (radiotherapy, temperature, climate, UV radiation, atmospheric pollution, in particular heavy metals, ozone, cigarette smoke, etc.) or even of mechanical origin (friction, shaving, cleaning, peeling, etc.) and by any stress of endogenous origin and then most often associated with an inflammatory component (psoriasis, atopic dermatitis, ichthyosis, dry skin, etc.).

[0020] Once a disruption of the skin barrier function has begun, whether chronic or acute, it leads to increased sensitivity of the body to attacks. external and dehydration. Therefore, the use of cosmetic compositions for the treatment of such skin pathologies will prove delicate knowing that it often results in the appearance of additional skin irritations.

[0021] Finally, this disruption of the skin barrier will lead to a visible appearance of dryness, itching, and even cause the skin to peel and flake, with, in some cases, also a disruption of desquamation and hyperproliferation.

[0022] There is a need for effective treatments for pathologies and conditions associated with impaired skin barrier function. Description of the embodiments

[0023] The inventors have now demonstrated that a composition comprising lanolin oil applied in the form of a spray makes it possible to moisturize skin suffering from dry skin, but also to soothe skin suffering from burns.

[0024] Consequently, a first subject of the invention relates to a composition for topical use in the form of a spray, which advantageously takes the form of a cosmetic or dermatological composition, and which comprises at least lanolin or one of its derivatives and at least one antioxidant.

[0025] Lanolin, otherwise known as "wool grease" or "wool wax", is a fat obtained by purification (removal of dirt such as sand, earth or various plants) and refining of suintine, which is the fatty part absorbed onto the wool and which is itself extracted from the wool washing water. In sheep, this suintine can constitute up to 10% of the weight of the wool, but its extraction processes generally only allow 40 to 50% to be collected. Compacted with most fatty substances, suintine is distinguished by a relatively low saponification index (around 100), by a very high proportion of unsaponifiables, nearly 50% and a very low iodine index (17 to 32). Suintine, from which lanolin is derived, is therefore in fact a wax composed essentially of a mixture of esters and fatty alcohols, accompanied by a small percentage of these alcohols in the free state and combined with a mixture of fatty acids.

[0026] The well-known process for obtaining lanolin aims to deacidify the suintine, to rid it of its impurities, to decolorize it, to deodorize it and, possibly, to dehydrate it.

[0027] After purification and refining, the lanolin obtained comprises olein (oil) and stearin (wax), namely a liquid fraction and a solid fraction. The latter consists of a mixture of esters and fatty acids (more than 180) with high molecular weight alcohols (more than 80). It is amphiphilic and forms very stable emulsions with water, moreover it is a very hygroscopic species. In addition, the composition of this lanolin presents a very strong similarity with the lipids of the Stratum Corneum.

[0028] Preferably, the lanolin derivative used is lanolin oil.

[0029] Liquid lanolin oil is produced from lanolin subjected to fractional crystallization at low temperature, in order to isolate the liquid esters from ordinary anhydrous lanolin. Such lanolin oil is much easier to work with than anhydrous lanolin due to its low viscosity.

[0030] As an example, we can cite the lanolin oils available from STELLA which are obtained by low temperature fractionation (crystallization) of a pharmaceutical lanolin.

[0031] The content of the composition in lanolin or one of its derivatives is advantageously greater than or equal to 50%, preferably greater than or equal to 75%, or even 95%, and particularly preferably the content of the composition is greater than or equal to 99%.

[0032] According to a particular embodiment, the content of the composition according to the invention is greater than or equal to 99.8%.

[0033] Advantageously, the composition according to the invention also comprises vitamin E as an antioxidant.

[0034] The name vitamin E actually covers a set of eight organic molecules with four tocopherols and four tocotrienols. Among them, the most biologically active form is α-tocopherol, the most abundant in food being γ-tocopherol. These molecules are present in large quantities in vegetable oils. They act, alongside vitamin C and glutathione, essentially as antioxidants against reactive oxygen species produced in particular by the oxidation of fatty acids.

[0035] Preferably, the vitamin E within the composition according to the invention is γ-tocopherol.

[0036] More preferably, the vitamin E within the composition has a natural origin.

[0037] Advantageously, the vitamin E content in the composition according to the invention is less than or equal to 0.2%, preferably this content is greater than or equal to 0.02%.

[0038] The composition according to the invention in spray form is in the form of droplets whose size is between 5 and 20 pm, preferably between 10 and 15 pm, ideally of the order of 12.5 pm.

[0039] The composition according to the invention advantageously comprises at least one propellant gas such as butane, isobutane or propane.

[0040] Advantageously also, the composition according to the invention does not comprise perfumes and, preferably, it also does not comprise colorants.

[0041] Advantageously still, the composition according to the invention does not comprise emulsifiers and, preferably, it also does not comprise solubilizers.

[0042] Advantageously, the composition according to the invention also does not comprise preservatives and, preferably, it does not comprise water.

[0043] A second subject of the invention relates to such a composition as a medicament.

[0044] Advantageously, the invention relates to such a pharmaceutical composition for its use in the treatment and / or prevention of dry skin conditions in a subject. Examples of such dry skin conditions include dermatoses such as atopic dermatitis, psoriasis, and ichthyosis conditions.

[0045] Advantageously still, the invention relates to such a pharmaceutical composition for its use in the treatment and / or prevention of small burns in a subject. Examples of such small burns include burns resulting from radiotherapy treatments. Preferably, such small burns correspond to superficial burns

[0046] Advantageously finally, the invention relates to such a pharmaceutical composition for its use in the treatment and / or reduction of the frequency of eczematous outbreaks observed in a subject suffering from atopic dermatitis.

[0047] As used herein, the term "treating" means curing a diseased state or condition already present in a patient or subject. Treating may also include arresting the development of the disease state or condition, and alleviating or ameliorating it, i.e., causing regression of the disease state or condition.

[0048] The term "prevent," as used herein, means to completely or nearly completely arrest the disease state or condition from its onset in a patient or subject, particularly when the patient or subject is predisposed to, or at risk of, contracting the disease state or condition. Preventing may also include arresting the development of the disease state or condition.

[0049] The term subject refers to a human, which can be a man or a woman.

[0050] Preferably, said subject has light skin.

[0051] According to another preference, said subject has dark skin.

[0052] More preferably, the subject has dry skin.

[0053] The inventors have demonstrated that the administration of the composition in the form of a spray at a dose of 2pl / cm2 makes it possible to obtain both a moisturizing effect and also a soothing effect in response to a burn, irritation or even a severe state of dryness, which state of dryness is then associated with itching.

[0054] Accordingly, the uses in a subject mentioned above use doses of between 0.1 and 100 pl / cm2, preferably between 0.5 and 10 pl / cm2 and particularly preferably between 1 and 5 pl / cm2.

[0055] Finally, the subject of the invention is a non-therapeutic cosmetic method for soothing and / or moisturizing the skin comprising at least one step of applying to the skin of a subject a cosmetic or dermatological composition as described above.

[0056] Naturally, by cosmetic method we mean a non-therapeutic method.

[0057] The following experiments are provided to illustrate embodiments of the invention and should not be construed as limiting the scope of the invention. EXAMPLES

[0058] 1. Detail of an emollient composition#

[0059] Body spray for the treatment of dryness and / or low-intensity burns

[0060] [Tables 1] Ingredients % (by weight) Vitamin E <0.2 Liquid lanolin (lanolin oil - STELLA - 70321-63-0) Qsp 100% 1. Evaluation of the soothing effect, skin tolerance and effectiveness of the emollient composition in relation to dry skin

[0061] An evaluation of the emollient composition is carried out on a first group of 22 adult volunteers with phototype II or III according to the Fitzpatrick classification, not exposed to the sun for at least two weeks before the study and presenting dry skin on the forearms (hydration level < 50 AU verified with the CM 825 COURAGE & KHAZAKA corneometer®).

[0062] At the start of the study, the inclusion criteria are checked on D0 for each of the volunteers. For eleven volunteers, two areas are defined on the forearms, one as the control area (untreated), the other as the area to be treated. The hydration rate is determined in particular with the corneometer ® for both areas.

[0063] The volunteers then apply the product twice a day (morning and evening), for 28 days.

[0064] The results showed very good tolerance of the composition according to the invention. At the same time, the composition according to the invention showed good preservation of the skin barrier and an anti-drying effect. This clear improvement in the condition of the skin was characterized by a significant reduction in skin dryness (38% on average), a reduction significant reduction in keratosis (47% on average), a significant reduction in erythema (75% on average), a significant reduction in roughness (60% on average) and a significant reduction in desquamation (91% on average).

[0065] At the same time, the volunteers reported a soothing effect with a significant reduction in the score of itching, sensations of dryness, sensations of roughness, tightness and discomfort (greater than 80%).

[0066] These properties contributed to a clear improvement in the quality of life of the volunteers, who appreciated the effectiveness from the start of the study and after 28 days of use.

[0067] 3) Evaluation of the soothing effect, skin tolerance and effectiveness of the emollient composition in connection with superficial burns

[0068] An evaluation of the soothing effect is carried out on a second group of 20 adult volunteers with phototype II or III according to the Fitzpatrick classification, not exposed to the sun for at least two weeks before the study and presenting dry skin on the forearms (hydration level < 50 AU verified with the comeometer®).

[0069] At the beginning of the study, the inclusion criteria are verified with, at D1, the determination of 4 distinct zones at the level of the back: a zone for the determination of the Minimum Erythemal Dose (MED), an irradiated zone treated with the product under study (IRT), an irradiated and untreated zone (IRNT) and a non-irradiated and untreated zone (NIRNT). The DEM is the smallest dose of Ultra Violet which, after 24 hours, produces the first perceptible erythema 16 to 24 hours after exposure to UV.

[0070] At D0, reading of the DEM determined at D1 for each of the volunteers, and reading of the skin color using the CM-700d type spectrocolorimeter ® for the 3 IRT, IRNT and NIRNT zones. Then, irradiation at 1.5 DEM is started for the IRT and IRNT zones. A standardized application of the 2pl / cm2 composition is then carried out by a technician on the IRT zone.

[0071] At 24h and 32h, reading of the skin color using the CM-700d type spectrocolorimeter ® for the 3 IRT, IRNT and NIRNT zones and standardized application of the 2pl / cm2 composition by a technician on the IRT zone.

[0072] At 48 hours, a final reading of the skin color is taken using the CM-700d type spectrocolorimeter ® for the 3 IRT, IRNT and NIRNT zones.

Claims

Claims

1. A composition for topical use in the form of a spray, which advantageously takes the form of a cosmetic or dermatological composition and which comprises at least lanolin or one of its derivatives and at least one antioxidant and the content of lanolin or one of its derivatives is greater than or equal to 75%.

2. The composition according to claim 1, characterized in that it comprises at least one lanolin derivative, which derivative is lanolin oil.

3. The composition according to any one of claims 1 or 2, characterized in that the content of the composition in lanolin or one of its derivatives is advantageously greater than or equal to 95%, and particularly preferably the content of the composition is greater than or equal to 99%.

4. The composition according to any one of the preceding claims, characterized in that it further comprises vitamin E.

5. The composition according to any one of the preceding claims, characterized in that it is in the form of droplets whose size is between 5 and 20 pm, preferably between 10 and 15 pm, ideally of the order of 12.5 pm.

6. The composition according to any one of the preceding claims, characterized in that: * It does not comprise perfumes and, preferably, it also does not comprise colorants; and / or * It does not comprise emulsifiers and, preferably, it also does not comprise solubilizers; and / or * It also does not comprise preservatives and, preferably, it also does not comprise water.

7. A composition according to any one of claims 1 to 6 as a medicament.

8. The pharmaceutical composition according to claim 7 for its use in: * the treatment and / or prevention of conditions of dry skin in a subject, such as dermatoses like atopic dermatitis, psoriasis, and ichthyosis conditions; * the treatment and / or prevention of minor burns in a subject, preferably superficial burns; and / or * the treatment and / or reduction of the frequency of eczematous outbreaks observed in a subject suffering from atopic dermatitis.