DE212009000107U1 - Dermatologically effective topical composition, in particular for the prevention and treatment of skin diseases - Google Patents

Abstract

Dermatologically effective topical composition, in particular for the prevention and treatment of skin diseases, characterized in that it comprises a textile carrier made of cellulose-containing fibers, the fibers being provided with an acidic surface layer which can be produced by esterification with a polycarboxylic acid, and that after up to 20 washes with a pH-neutral detergent, it has a pH value of at most 6.5 measured on its surface.

Description

Technical area

The invention relates to the general field of functional textiles and more particularly to a dermatologically effective typical composition comprising a textile carrier.

State of the art

Symptoms such as atopic dermatitis, aging skin, diabetes and occupational eczema (due to heavy sweating or moisture exposure) may be due to various causes such as a reduced pH buffer capacity of the skin, impaired or destroyed skin water vapor barrier, infections by penetrating contact allergens or an altered microbiology of the skin Skin (colonization by staphylococci) have. Typical symptoms or manifestations include itching, redness, eczema and psoriasis. In the Swiss population, for example, around 16% of young children suffer from atopic dermatitis and about 0.5% of the total population from psoriasis.

The influence of textiles as a cause of skin irritation and the ability to prevent and therapeutic by targeted adaptation of clothing has long been studied ( Elsner P. et al., Textiles and the Skin, Current Problems in Dermatology, Vol. 31, Karger, 2003 ). Up to now, investigations on fiber morphology, dyes, pesticides, auxiliary textile chemicals (eg plasticizers, optical brighteners) and detergent ingredients (enzymes, surfactants) have been in the foreground. On the other hand, a parameter hardly considered until now is the pH value of textiles. Compared to the physiological pH of the skin (about 5.5 to 6.5, depending on age, sex and body zones), textiles usually have a significantly higher pH of about 7 to 9, which is also strongly influenced by the nature of the skin Care (washing) is affected.

Furthermore, it is known that healthy skin is hardly affected by fluctuating pH values of the clothing in the range between 4.6 and 10.1 ( Matthies W, Effect of pH on Skin Compatibility of Cotton Textiles, Dermatoses, 1993, 41, 97-100 ). By contrast, the influence on diseased skin is unknown. Is known, however, the stimulating effect of slightly acidic substances such. As lactic acid and various amino acids in the healing of diseased skin ( Schmid-Grendelmeier P. et al., Basic / concomitant therapy and prevention of dermatoses. Consensus Statement, International Journal of Medical Education. No. 38; Nov 2005 ). In a double-blind, placebo-controlled study, pH-low latex gloves were found to be significantly better for skin barrier preservation than biophysical measurements when compared to regular latex gloves ( Mirza R. et al. PH, transepidermal water loss and skin irritation, Contact dermatitis, 2006, 55, 20-25 ).

In the EP 0 138 179 A2 pH-regulating materials are described, which are formed from a uniformly acidic, chemically modified viscose fiber, and in particular for the production of welding pads or shoe inserts are provided. The disadvantage here is that materials that are chemically modified holistically as in the viscose, change their material properties emphatically. Thus, there is usually a greatly increased hydrophilicity, which is undesirable for clothing textiles because of increased absorption of perspiration, as well as a reduced durability as a result of damage to the cotton fiber by the strongly acidic substances used.

The also already proposed purely physical adsorption of acidic substances on textile fibers has the disadvantage that the residence time on the fiber is sufficient at most for a disposable product. In particular, such products can not be washed.

Presentation of the invention

The object of the invention is to provide a new means for the prevention and treatment of skin diseases.

This object is achieved according to the invention by the defined in claim 1 dermatologically effective topical composition. This comprises a textile carrier of cellulose-containing fibers, wherein the fibers are provided with an acid-acting surface layer which can be produced by esterification with a polycarboxylic acid. In addition, the composition according to the invention has, after up to 20 washes with a pH-neutral detergent, a pH of at most 6.5 measured on its surface.

The composition according to the invention is suitable for wearing on the skin or laying on top and makes it possible to adjust or maintain a physiologically advantageous pH at the skin surface with a textile part. The good washing resistance in particular opens up various possible uses as articles for multiple use. The composition is particularly suitable for preventive and / or therapeutic use in patients with pathologically altered water vapor barriers of the skin. When important application should avoid eczema, psoriasis or dermatoses in endangered persons or their healing should be supported.

By suitable choice of the reaction conditions can be achieved that the individual Polycarbonsäuremoleküle are esterified via one (or optionally more) of its carboxyl groups with the cellulose, but next at least one free carboxyl group. Accordingly, in the context of the present invention cellulose-containing fibers of a textile carrier are provided by treatment with a polycarboxylic acid with a superficial coating which still has free acid groups. Due to the covalent attachment of the Polycarbonsäuremoleküle to the cellulose framework, the acidic coating is very durable and durable.

In contrast to the viscose process, in which substantially all of the cellulose material is sustainably chemically modified, in the composition according to the invention only a layer near the surface of the cellulose-containing fibers is modified. Therefore, the textile handle is not affected, and there are no changes in tear strength, seam slip resistance, tear resistance and residual shrinkage. When used in garments, a similar behavior is to be expected in thermo-physiological terms as with cotton without acid coating.

The composition according to the invention can be produced by a simple process, which is particularly applicable to finished cotton textiles.

Advantageous embodiments of the invention are defined in the dependent claims.

In principle, various types of cellulosic fibers are suitable for the textile carrier, with cotton fibers being particularly preferred.

It is understood that there is some latitude in the choice of polycarboxylic acid, with comparatively small aliphatic and alicyclic polycarboxylic acids having up to 10 carbon atoms in total being particularly suitable. It must be ensured that dermatologically acceptable polycarboxylic acids are used.

Examples of suitable polycarboxylic acids are dicarboxylic acids such as malic acid (2-hydroxyethane-1,2-dicarboxylic acid) or tartaric acid (2,3-dihydroxybutane-diacid). However, a particularly preferred polycarboxylic acid is citric acid (2-hydroxypropane-1,2,3-tricarboxylic acid).

As expected, the pH immediately after application of the acidic coating depends on the dissociation constants or pK _s values of the selected polycarboxylic acid. For example, after being supplied with citric acid, a pH of 2.0 to 3.0 was determined according to the procedure described below. Since such low pH values are unsuitable for topical application, an increase in pH must be raised to a physiologically acceptable range of about pH 5 prior to the first (or only) use. This can be achieved, for example, by a washing operation carried out by the supplier. Alternatively, the acidic coating can be carried out with a weaker polycarboxylic acid, so that from the outset not so low pH values are achieved.

The composition according to the invention can be designed in many different ways. For example, it can be used as bedding, hygiene products, wipes, baby diapers, incontinence products but also for plasters, wound dressings and gauzes. In an advantageous embodiment, the inventive composition forms at least one skin-facing layer of a garment, which may be, for example: pants, T-shirt, underwear, shirt, blouse, glove, headgear and the like. Especially with such multiple-use articles, the above-mentioned wash resistance is particularly important.

According to a further aspect of the invention, a polycarboxylic acid, preferably citric acid, is used for the preparation of a dermatologically active topical composition for the prevention and treatment of skin diseases.

Brief description of the drawings

Exemplary embodiments of the invention will be described in greater detail below with reference to the drawings, in which:

1 the measured pH of two uncoated fabric samples A (comparative examples) and of two acid-coated fabric samples B (examples), either unsprayed (designation A _o or B _o ) or once rinsed with deionized water (designation A _s or B _s ), unwashed (open symbols) and after a standard wash (filled symbols); and

2 the measured pH of the fabric sample B _o in the course of 20 washes.

Detailed description of the invention

Production of textile carriers with acidic coating

The experiments described below were performed with wrinkle-free cotton fabric samples of the size DIN A3 carried out.

In order to have a comparison basis, some of the samples were not provided with an acidic coating. These patterns are hereinafter referred to as "uncoated" and marked with the symbol "A".

The remaining samples were treated as follows: Each sample was placed in a 250 mL bottom flask and 80 mL deionized water added. 2.1 g (10 mmol) of citric acid monohydrate (C ₆ H ₈ O ₇ .H ₂ O, M = 210.14 g / mol) and 2.12 g (20 mmol) of sodium hypophosphite monohydrate, (H ₂ NaO ₂ P · H ₂ O, M = 105.99 g / mol), the mixture was refluxed for 10 minutes and then left to cool. Then the fabric was taken out, pressed by hand and allowed to air dry. Subsequently, the samples were treated for 3 min at 130 ° C in a warming cabinet. The patterns thus treated are hereinafter referred to as "coated" and marked with the symbol "B". The samples were rinsed briefly by hand with about 200 mL of deionized water three times, squeezed by hand and allowed to air dry.

To clarify whether the quality of the acidic equipment depends on the cleanliness or the presence of flushable components in the supplied fabric samples, half of the fabric samples were pre-rinsed in a standard wash with no detergent and deionized water. In the case of the fabric samples B, the acidic coating was then applied, in the case of the fabric samples A, no further treatment steps were carried out.

washing tests

All washing tests were carried out with a pH-neutral detergent and local tap water at the EMPA St. Gallen. The pH of the tap water ranged from 7.5 to 8; after admixing the pH neutral detergent, the pH was about 7. For all experiments, the same standardized washing procedure was used, hereinafter referred to as "standard washing". The program "dress shirts" was carried out on a Miele Softtronic W-35-21 CH washing machine. This is characterized by a total washing time of 56 minutes and a nominal temperature of 40 ° C. In each case, 40 ml of pH-neutral mild detergent (Oecoplan brand, COOP) were added to about 12 liters of water. At the end of the wash, 2 extra washings were performed to remove any residual detergent.

pH measurements

The following pH values were measured with a pH meter from Courage-Khazaka (cutometer MPA 580) and a pH electrode Metier-Toledo (InLab Surface; flat glass membrane with ground diaphragm). To prepare a pH-neutral measuring solution, 500 ml of deionized water were mixed with 1 ml of saturated KCl. This increases the conductivity, resulting in a fast and stable pH signal. During the actual measuring procedure, 0.1 ml of the pH-neutral measuring solution was added to the textile and then the pH value was determined immediately by placing the two-dimensional pH electrode (20 seconds waiting time until stable, 3 to 5 repetitions per textile sample). The absolute accuracy of the pH measurements was determined to be ± 0.2 pH units. In the following illustrations, only the mean value of a series of measurements is shown.

Results after a single standard wash

In the 1 the results of four different types of fabric types are shown, namely:
A _o uncoated, not rinsed (= Comparative Example 1)
A _s uncoated, rinsed (= Comparative Example 2)
B _o coated, not rinsed (= Example 1)
B _s coated, pre-rinsed (before application of the coating) (= Example 2)

The bottom dot (open symbols) represents the measured pH of the unwashed samples, the top dot (solid symbols) represents the pH after a single standard wash ("washed").

From the 1 shows that pre-rinsing the samples prior to equipping with the acidic layer has no significant effect on the pH. The uncoated samples had a slightly acidic pH within the range of about 6.3 to 6.8 before the first wash, but this increased to 7.0 even after a single wash. In contrast, the pH of the coated samples prior to the first wash in the highly acidic region was about 2.3 to 2.5 and increased to 5.8 to 6.0 after a single wash, which is in the desired physiologically acceptable and preventive or curative effective range.

Washable over 20 standard washes

• – direkt nach Aufbringen der sauren Schicht: pH 2.5
• – 1-mal Waschen: pH 6.0
• – 5-mal Waschen: pH 6.2
• – 10-mal Waschen: pH 6.3
• – 20-mal Waschen: pH 6.3.

A number of B _o type samples, ie having an acidic surface layer applied to the non-rinsed fabric swatch, were subjected to an extended wash resistance test. The samples were washed at different times with the standard washing procedure described above (1, 5, 10 and 20 times), then their pH was determined. The following pH values were measured (see 2 ):

• - immediately after application of the acidic layer: pH 2.5
• - Wash once: pH 6.0
• - 5 times washing: pH 6.2
• - Wash 10 times: pH 6.3
• - Wash 20 times: pH 6.3.

Closing remarks

The wash series over a total of 20 standard washes has shown that the pH is still in the target range (5.5 to 6.5) even after 20 washes, but a slight and constant increase is measurable with each wash. Possible reasons may be favored by the wash liquor hydrolyzing the acidic molecules (breaking the bond to the cotton), the mechanical aging of the tissue (and the associated detachment of wrinkle-free equipment, fillers, dyes, etc.) or the deposition of ingredients from the Detergents (fragrances, fillers, surfactants, etc.) should be considered.

Pre-rinsing the supplied cotton samples with deionized water (by EMPA Testmaterialien AG) had no major impact on the quality of the following equipment with citric acid. Nevertheless, it must be ensured in an industrial process that no water-soluble residues from the production (finishing) or refining (wrinkle-free equipment) are present before equipment with acidic molecules. These would undoubtedly reduce the durability of further functionalization with acidic groups.

Basic washing powders or detergents should generally be avoided as otherwise the acidic character of the textile will be lost. It should also be noted that some detergents contain a variety of enzymes, fillers, optical brighteners, polymers, perfumes, antistatic agents, etc. Such detergents are unsuitable because the deposition of said additives on the surface of the fabric would result in an undesirable change in pH.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0138179 A2 [0005]

Cited non-patent literature

• Elsner P. et al., Textiles and the Skin, Current Problems in Dermatology, Vol. 31, Karger, 2003 [0003]
• Matthies W, Influence of pH on Skin Compatibility of Cotton Textiles, Dermatoses, 1993, 41, 97-100 [0004]
• Schmid-Grendelmeier P. et al., Basic / concomitant therapy and prevention of dermatoses. Consensus Statement, International Journal of Medical Education. No. 38; Nov 2005 [0004]
• Mirza R. et al. PH, transepidermal water loss and skin irritation, contact dermatitis, 2006, 55, 20-25 [0004] A latex glove treated with standard powder-free latex gloves on skin pH, transepidermal water loss and skin irritation.
• DIN A3 [0023]

Claims (7)

Dermatologically active topical composition, in particular for the prevention and treatment of skin diseases, characterized in that it comprises a textile carrier of cellulosic fibers, wherein the fibers are provided with an acidic surface layer, which can be prepared by esterification with a polycarboxylic acid, and it has up to 20 washes with a pH-neutral detergent having a measured at its surface pH of at most 6.5. Composition according to Claim 1, characterized in that the textile carrier is formed from cotton. A composition according to claim 2, characterized in that the textile carrier is equipped wrinkle-free. Composition according to any one of the preceding claims, characterized in that the polycarboxylic acid is citric acid. A composition according to any one of the preceding claims as a skin-facing layer of a garment. Use of a polycarboxylic acid for the manufacture of a dermatologically active topical composition for the prevention and treatment of skin diseases. Use according to claim 6, wherein the polycarboxylic acid is citric acid.

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