DE19838030C1 - Urea-containing dermatological compositions containing diglycerine and lactic acid-sodium lactate buffer - Google Patents

Abstract

A dermatological composition comprises 3-10 wt. % urea, 2-4 wt. % diglycerine, 0.5-1.5 wt. % lactic acid, 0.5-3 wt. % sodium lactate and the balance water and other additives.

Description

The invention relates to a dermatological composition as a component Has urea. Urea is used in many cosmetic and therapeutic der matika because of the hydrating, keratolytic and in high concentrations bactericidal effect. The indication for more concentrated applications are dry, cracked or chapped skin, in low doses improves urea the moisturizing effect of emulsions. A generic dermato logical composition has become known from US 5,525,635 A.

The disadvantage of the known dermatological compositions with urea lies in the fact that it contains potentially negative active ingredients or auxiliaries. Example known compositions contain mineral oils such as petroleum jelly and paraffin, to which comedogenic effects are attributed, or potentially allergenic substances such as parabens as a preservative, cetyl or stearyl alcohol as a consistency gene About, gallates as antioxidants or propylene glycol as a humectant.

The invention is therefore based on the object of a dermatological composition to create the one with the greatest possible freedom from irritation and wide usability has good moisture retention.

According to the invention, this object is achieved by a dermatological composition solved with the features of claim 1.  

The advantage of the invention is that despite the greatest possible freedom from irritation Components have good hydration ability of the overall preparation. The In their combination, lactic acid and sodium lactate have a high content Moisturizing effect, plus a slight keratolysis with high penetration into the Epidernis. Lactic acid is buffered by sodium lactate, the overall preparation a slightly acidic, i.e. physiological pH value. Although diglycerin represents a stabilizer for emulsifiers, one achieves a synergy effect with respect the moisturizing effect together with the components lactic acid and sodium acetic acid did. Due to the good hydration and penetration ability, the lengthens Duration of action and the intensity of action of urea by the inclusion of Water favors, but its evaporation or loss from the epidermis is effective is encountered.

According to one embodiment of the invention, polyglyceryl 3Dimerate is used as an emulsifier tor use. With this emulsifier you get a water-in-oil emulsion in which the water content can be unusually high at around 60%. Basically water-in-oil emulsions have a lower effect due to their occlusive effect Loss of water evaporation as well as better water and active substance penetration. The The maintenance effect is considerably lower than that of an oil-in-water emulsion perceived cooling effect as subjectively large and pronounced. However, act Water-in-oil emulsions are often heavy and greasy. With the emulsifier polyglyceryl 3Dimerate can consequently be the objectively better curative effect of a water-in-oil Emulsion with the subjective feeling of application and the sensor technology comparable to one Oil-in-water emulsion are created. You get a pleasantly light one, but still sufficiently nourishing preparation.  

With regard to the fats used, skin-affine, partly nature-identical lipids selected, which have particularly high quality and nourishing properties. With the specified oils include oleyl erucate, octyldodecanol and dicaprylyl ether Fat phase slow, medium and fast spreading components. This Wed The good application properties and sensor technology are responsible for this. With the ingredients oleyl erucate, octyldodecanol and dicaprylyl ether are produced consequently a long-lasting feeling of smoothness and care felt from the start without greasy or sticky impression.

The additive allantoin serves on the one hand as a stabilizer for the urea and others on the other hand, a therapeutic effect is achieved.

The addition of magnesium sulfate also has a stabilizing effect, with further ver improvement of the therapeutic effect. Furthermore, the skin feeling improves because no sticking is generated.

Phenoxyethanol is used as a preservative.

Embodiments of the invention are described below, the % Figures relate to percentages by weight.

Example of a water-in-oil lotion with a low urea content:

3.0% urea, 2.5% diglycerin, 1.0% lactic acid, 2.0% sodium lactate, 3.0% polygly ceryl-3Dimerate, 9.0% oleyl erucate, 9.0% octyldodecanol, 5.0% dicaprylyl ether, 0.25% allantoin, 1.0% magnesium sulfate, 0.5% phenoxyethanol, remainder: distilled Water.

Example of a water-in-oil lotion with a high urea content:

10.0% urea, 2.5% diglycerin, 1.0% lactic acid, 2.0% sodium lactate, 3.0% polygly ceryl-3Dimerate, 8.0% oleyl erucate, 10.0% octyldodecanol, 5.0% dicaprylyl ether, 0.5% phenoxyethanol, 0.25% allantoin, 1.0% magnesium sulfate, remainder: distilled Water.

Example of a water-in-oil cream:

5.0% urea, 2.5% diglycerin, 1.0% lactic acid, 2.0% sodium lactate, 3.0% polygly ceryl-3Dimerate, 8.0% oleyl erucate, 7.0% octyldodecanol, 5.0% dicaprylyl ether, 0.2% allantoin, 1.0% magnesium sulfate, 0.5% phenoxyethanol, 0.6% cetyl palmitate, 0.4% hardened castor oil, rest: distilled water.

The above-mentioned dermatological compositions can be produced as follows, for example, using a mixing bowl / pestle, an Unguator® jar or a Stephan's ointment machine:

• - Oleyl erucate, octyldodecanol, dicaprylyl ether, polyglyceryl 3Dimerate are on heated to about 80 ° C in the water bath, during the preparation of the cream until clear melt of cetyl palmitate and hardened castor oil.
• - In parallel, the water phase with urea, allantoin, diglycerin and magnesium sulfate also heated on the water bath to approx. 80 ° C until all components are clear solves; Lactic acid and sodium lactate solution are added.
• - The hot water phase is at about 75 ° C in the equally hot fat phase in small Portions stirred in; a homogenization step follows. Regarding the recipe a gap homogenizer (approx. 1 min), an Unguator® system or a laboratory stirring system with high-speed stirrer and scraper (2 min) was used become. Overemulsification creates a strong consistency, the cons creative to break the emulsion with total loss of consistency (within Ta up to weeks) and should therefore be avoided.
• - The preservative phenoxylethanol is added at approx. 40 ° C; it will again homogenized vigorously as described above.
• - The emulsion should be stirred all the time up to room temperature (25 ° C) (Low speed agitator and scraper).
• - Care should be taken not to over-homogenize (Particle size: approx. ≦ 1 µm).

With regard to the feasibility of the invention, particularly good results are achieved with the following products available on the market in order to produce the abovementioned dermatological compositions:

• - Isolan PDI® is suitable as a polyglyceryl 3Dimerate;
• - Cetiol J 600® is suitable as oleyl erucate;
• - Eutanol G® is suitable as octyldodecanol;
• - Cetiol OE® is suitable as dicaprylyl ether.

Claims (4)

1. Dermatological composition based on urea, lactic acid and optionally pharmaceutically acceptable excipients, characterized in that it consists of
3 to 10% by weight of urea,
2 to 4% by weight diglycerin,
0.5 to 1.5% by weight of lactic acid,
0.5 to 3% by weight sodium lactate,
Rest of additives and water
consists. 2. Composition according to claim 1 characterized in that they additionally 2.5 to 5 wt .-% polyglyceryl 3Dimerate as an emulsifier having. 3. Composition according to claim 1 or 2, characterized in that it
6 to 11% by weight of oleylerucate,
5 to 12 wt .-% octyldodecanol and
3 to 7% by weight of dicaprylyl ether
contains as an additive. 4. Composition according to one of claims 1 to 3, characterized in that it has the following additives individually or in a mixture:
0.2 to 0.5% by weight of allantoin,
0.5 to 2% by weight of magnesium sulfate,
0.2 to 1% by weight phenoxyethanol.