Department Dermocosmetics

Guidelines "Dermocosmetics for dry skin care" (version 17 February 2000)

These guidelines have been preliminarily adopted at the workshop of the department Dermocosmetics under the title "Dermocosmetics for dry skin - concept for guidelines for the development, documentation and dermatological analysis". This workshop took place on the occasion of the GD's 3rd annual meeting in Berlin (Marienfelde) under the joint leadership of professor Dr. Rolf Daniels, Braunschweig and professor Dr. med. Volker Wienert, Aix-la-Chapelle.

This current version was subject to final discussion in Düsseldorf on 17 February 2000 and released for publication by the department Dermocosmetics.

1
Preamble
2
Definition dermocosmetics
3
Target group and purpose
4
Definition of dry skin
5
Formulations and ingredients
6
Wanted effects and efficacy proofs
7
Unwanted effects and tolerability proofs
8
Documentation
9
Literature
10
Elaborated by

1 Preamble

The care of dry skin is an essential part of prophylaxis as well as an important accessory measure during and after a dermatological therapy aiming at re-establishing the normal skin condition. A product recommendation should only be given if certain quality demands have been ensured, i.e. galenic properties, wanted and unwanted effects as well as efficacy and tolerability proof have been adequately documented. So far a standardized, interdisciplinary coordinated concept has not been established. The department Dermocosmetics of the Gesellschaft für Dermopharmazie e.V. (Society for Dermopharmacy registered society) as independent organization has defined as one of their tasks to stipulate minimal requirements concerning quality and documentation in the form of the present guidelines. It is intended to give support to all those who are concerned with dermocosmetics for the care of dry skin.

These guidelines are a systematically elaborated recommendation which offers guidance for decisions about appropriate measures for the care of dry skin to the target group. They have been prepared by an interdisciplinary expert group by evaluating of the relevant international literature.

They apply to "standard situations" and take into consideration the current scientific findings available for the corresponding formulations of questions. The guidelines require continuous revision and possibly modifications on the basis of the respective scientific findings and the practicability of everyday practice. Observation of the guidelines does not ensure in every case to achieve the intended objective. It does not lay claim to completeness.

2 Definition dermocosmetics

The term "dermocosmetics" assigns measures for cleaning, protection and care of skin, the purpose of application of which is achieved under mutual consideration of dermatological and pharmaceutical aspects. Cosmetic products which meet this standard are designated "dermocosmetics".

Dermocosmetics for the care of dry skin

Dermocosmetics for the dry skin care are such products for which the intended purpose "for dry skin" and "application for dry skin" is indicated.

They should compensate its lack of moisture and fat and improve its barrier function at the same time.

As all cosmetic products, dermocosmetics for the dry skin care equally underlie the EC cosmetic guidelines. As legal basis in the German Federal Republic serves the food and convenience law in combination with the cosmetics ordinance in its respective formulation.

3 Target group and purpose

Target group for these guidelines are persons developing, manufacturing, testing, analysing, commercialising, selling, giving advice as to their application as well as users of dermocosmetics for dry skin care.

These guidelines are a systematically elaborated representation and recommendation. They describe quality demands for products and offer the a.m. persons assistance to make decisions regarding their measures as to the care of dry skin.

4 Definition of dry skin

The term dry skin (xerosis, xerodermia) describes a skin condition which is characterized by a reduced quantity and/or quality of humidity and/or lipids. Objectively the appearance of dry skin is characterized by roughness, scaling, dullness and/or a lack of elasticity. Subjectively a sensation of tension and itching may appear at dry skin. These subjective symptoms may also manifest in an isolated way.

Dry skin in the sense of these guidelines is to be understood as a symptom and not isolated as a clinical defined dermatosis, as for instance a dermatitis, psoriasis or ichthyosis.

Dry skin always reacts more intensely than normal, not dry skin to external chemical and physical noxae.

According to expert opinions there is a large number of persons suffering from dry skin; only in Germany a few million people are concerned. Epidemiological data are not available.

The exact etiopathology of dry skin is still open. Persons who are inclined to atopy have a defect of the barrier function of the horny layer of the epidermis which can result in a transepidermal dehydration. Above all the epidermal horny layer lipids are missing [1, 2, 3]. Dry skin may, however, also be caused by a sebostasis (reduced sebaceous oil gland activity) [4]. Likewise a reduced water storing capacity may be the case.

Causes and development

Dry skin is either determined genetically or acquired at a later point of time in life. It appears as a symptom of a skin disease, e.g. the atopical dermatitis [5], an internal disease, e.g. a nephric disease [6] or a diabetes mellitus [7]. Dry skin may also come into being caused by exterior influences, as for instance by having showers or taking baths too frequently and too intensely with or without using soaps or syndets [8, 9, 10, 11]. Moreover, occupational strains, e.g. when practising "moist professions (hairdressers, etc.) as well as work in the construction or metalworking trade [12] may cause the appearance of dry skin. This also applies to climatical factors, as low temperatures or too low an atmospheric humidity [13].

Diagnostics:

Indications by the persons concerned and a visual and palpatoric examination lead to the diagnosis of dry skin. Apparative diagnostic methods are among others: measuring of the skin roughness [5, 14, 15], moisture measurement [16], determination of the transepidermal loss of water, the fat content and the scale formation [19] as well as the measurement of skin gloss [20].

5 Formulations and ingredients

The efficacy of dermocosmetics for the dry skin care is connected with the overall formulation.

The scientific findings generally allow varying formulation types, e.g. w/o emulsions or o/w emulsions for the dry skin care.

For some ingredients, as vaseline [21], certain lipids [22, 23], urea [24, 25], glycerine [26], vitamin E [27] and adenosintriphosphate [28], positive results are available regarding the efficacy proof for dry skin. However, for an assessment the effect of the vehicle has also to be considered.

6 Wanted effects and efficacy proofs

Effects as for instance an increase of the lipid and water content of the skin, a smoothening of skin as well as a reduction of scale formation and an improvement of the barrier function have to be proven by suitable in-vivo-methods according to the respective scientific findings. Measuring methods are qualified if they provide relevant, reproducible and valid results.

For an efficacy proof the methods indicated for the diagnostics are applicable (refer to chapter "definition of the dry skin")...

The basis of an efficacy proof is on the one hand a comparison with non-treated areas of dry skin as a control and on the other hand the starting level, i.e. the level before starting the treatment (intra-individual comparison).

Due to the possibly marked inter-individual differences of the skin condition, comparisons between treated and untreated probationer groups are only recommendable for appropriate large control groups. The study design has to be chosen in a way that the number of probationers is sufficiently large when applying suitable statistical methods in order to obtain any indication as to the differences.

Regarding details of the study design reference is made to the relevant specialized literature [31].

The assertion relating to a conditioning effect does not require a separate evidence.

7 Unwanted effects and tolerability proofs

Risks of the application of dermocosmetical products for dry skin are as for other  topically applied preparations incompatibility reactions, as acute or chronical-cumulative irritative contact dermatitis, sensoric irritations or allergic contact dermatitis on the basis of a sensitisation of the delayed reaction type.

To what extent the regenerating capacity of skin is influenced after the application of dermocosmetics for the dry skin care or whether break-off phenomena occur has not been subject to investigation up to date.

For the investigation and assessment of these risks, qualified in-vivo and in-vitro methods can be used [29]. Controlled application tests (utility tests) can be carried out in combination and as supplementation [30].

The occlusive, epicutaneous patch test is recommended as method for the coverage of the risk of an acute irritation [31].

The chronical-cumulative irritation can be recorded by using the cumulative-epicutaneous patch test [32].

Procedures have been established to test the sensorial irritation. They make use of the fact that organic acids, e.g. sorbic acid produce a comparable stinging sensation [33].

As topical skin care products in general only have a minor irritation potential, special attention is to be paid for the realization of tolerability tests so that the number of probationers is sufficiently high to obtain significant results when applying adequate statistical methods.

No validated and ethically general accepted methods are available at present for the recording of the sensitisation potential of dermocosmetics for the dry skin care. Alternatively a thorough selection of raw materials is recommended and an avoidance of using allergens with a comparably high sensitisation potential as known from relevant literature.

Moreover, a tolerability test of finished products by using a ROAT (Repeated Open Application Test) is useful. This test is particularly indicated when unclear positive reactions achieved in the epicutaneous test have to be verified [36].

8 Documentation

The manufacturer or distributor, respectively, of a dermocosmetic product for dry skin care should document all information which is necessary for the quality assessment of such a product and should render it accessible to the expert groups.

This documentation should cover at least the following issues:

description of the galenic system
indications as to stability and microbiological stability
  efficacy proofs regarding the properties assured for the dry skin care in the form of a summay report mentioning the reference
 summary of the results obtained from the tolerability studies referring to the examining institution.

   

9 Literature

(1) Imokawa G, Abe A, Jin K et al.: Decreased level of ceramides in stratum corneum of atopic dermatitis: An etiologic factor in atopic dry skin? J. Invest. Dermatol. 96, 523-526, 1991

(2) Di Nardo A, Wertz P, Gianetti H et al.: Ceramide and cholesterol composition of the skin of patients with atopic dermatitis. Acta Derm. Venereol. 78, 27-30, 1998

(3) Melnik B, Hollmann J, Plewig G: Decreased stratum corneum ceramides in atopic dermatitis individuals - a pathobiochemical factor in xerosis? Br. J. Dermatol. 119, 547-549, 1988

(4) Proksch E: Die Permeabilitätsbarriere der Epidermis und ihre Beeinflussung durch Detergentien und Lokaltherapeutika. Ärztl. Kosmetol. 19, 424-434, 1989

(5) Linde YW, Bengston A, Loden M: Dry skin in atopic dermatitis. A surface profilometry study. Acta Derm. Venereol. 69, 315-319, 1989

(6) Morton CA, Lafferty M, Hau C et al.: Pruritus and skin hydration during dialysis. Nephrol. Dial. Transplant. 11, 2031-2036, 1996

(7) Yosipovitch G, Hodak E, Vardi P et al.: The prevalence of cutaneous manifestations in IDDM patients and their association with diabetes risk factors and microvascular complications. Diabetes Care 21, 506-509, 1998

(8) Gammel CE, Pagnoni A, Kligman AM, el Gammal S: A model to assess the efficacy of moisturizers - the quantification of soap-induced xerosis by image analysis of adhesive coated discs. Clin. Exp. Dermatol. 21, 338-343, 1996

(9) Gfatter R, Hackl P, Braun F: Effects of soap and detergents on skin surface pH, stratum corneum hydration and fat contents in infants. Dermatology 195, 258-262, 1997

(10) van der Falk PG, Cryns MC, Nater JP: Skin irritancy of commercially available soap and detergent bars as measured by water vapour loss. Clin. Exper. Dermatol. 10, 98-103, 1984

(11) Bechor R, Zlotogorski A, Dikstein S: Effect of soap and detergents on the pH and casual lipid levels of the skin surface. J. Appl. Cosmetol. 6, 123-128, 1988

(12) Svendjen K, Hilt B: Skin disorders in ship’s engineers exposed to oils and solvents. Contact Dermatitis 36, 216-220, 1997

(13) Eberlein-König B, Spiegl A, Przybilla B: Change of skin roughness due to lowering air humidity in a climate chamber. Acta Derm. Venereol. 76, 447 - 449, 1996

(14) Rohr M, Schrader K: Fast optical in vivo topometry of human skin (FOITS) – Vergleichende Untersuchungen zur Laserprofilometrie. SÖFW 2, 3-8, 1998

(15) Tronnier H., Wiebusch M., Heinrich U., Stute R.: Zur Bewertung der Oberflächenstruktur der Haut (SELS) Akt. Dermatol. 23, 290 - 295, 1997

(16) Wienert V, Hegner G, Sick H: Ein Verfahren zur Bestimmung des relativen Wassergehaltes des Stratum corneum der menschlichen Haut. Arch. Dermatol. Res. 270, 67-75, 1981

(17) Pinnagoda J, Tupker RA, Serup J: Guidelines for transepidermal waterloss (TEWL) measurement. Contact Dermatitis 22, 164-178, 1990

(18) Barel AO, Clarys P: Study of the stratum corneum barrier function by transepidermal water loss measurements: Comparison between two commercial instruments: Evaporimeter® and Tewameter®. Skin Pharmacol. 8, 186-195, 1995

(19) Serup J, Winther A, Blichmann C: A simple method for the study of scale pattern and effects of moisturizer - qualitative and quantitative evaluation by D-squame tape compared with parameters of epidermal hydration. Clin. Exp. Dermatol. 14, 277-282, 1989

(20) Lentner A, Wienert V: A new method for assessing gloss of human skin. Skin Pharmacol. 9, 184-189, 1996

(21) Petersen EN: The hydrating effect of a cream and white petrolatum measured by optothermal infrared spectrometry in vivo. Acta Derm. Venereol. 71, 373-376, 1991

(22) Imokawa G, Kasaki SA, Hattori M et al.: Selective recovery of deranged water-holding properties by stratum corneum lipids. J. Invest. Dermatol. 87, 758-761, 1986

(23) Gehring W., Wenz J., Gloor M.: Influence of topically applied ceramide / phospholipid mixture on the barrier function of intact skin, atopic skin and experimentally induced barrier damage. Int. J. Cosm. Sci. 19, 143 - 156, 1997

(24) Loden M: Urea-containing moisturizers influence barrier properties of normal skin. Arch. Dermatol. Res. 288, 103-107, 1996

(25) Bettinger J., Gloor m., Gehring W.: Influence of a pretreatment with emulsions on the dehdration of the skin by surfactants. Int. J. Cosm. Sci. 16, 53 - 60, 1994

(26) Gloor M, Schermer S, Gehring W: Ist eine Kombination von Harnstoff und Glycerin in Externa sinnvoll? Z. Hautkr. 72, 509-514, 1997

(27) Gehring W, Fluhr J, Gloor M: Influence of vitamin E acetate on stratum corneum hydration. Arzneim.-Forsch./Drug Res. 48, 772-775, 1998

(28) Tennigkeit J, Schrader K: Hautphysiologische Wirkungen unterschiedlicher Adenosinphosphate. Parfümerie und Kosmetik 72, 294-301, 1991

(29) Fischer T, Greif C, Wigger-Alberti W, Elsner P: Instrumentelle Methoden zur Bewertung der Sicherheit und Wirksamkeit von Kosmetika. Akt. Dermatol. 24, 243-250, 1998

(30) COLIPA: Cosmetic Product Test Guidelines for the Assessment of Human Skin Compatibility. 1995

(31) Matthies W.: Dermatologische Testmethoden zur Bewertung der lokalen Verträglichkeit von Fertigprodukten – Die neue COLIPA-Guideline als Beitrag zur Sicherheitsbewertung kosmetischer Mittel gemäß 6. Änderungsrichtlinie der EU-Kosmetik-Richtlinie. Dermatosen 45, 154-159, 1997

(32) Kligman AM, Wooding WM: A method for the measurement and evaluation of irritants on human skin. J. Invest. Dermatol. 49, 78-94, 1967

(33) Lammintausta K, Maibach HI, Wilson D: Mechanisms of subjective (sensory) irritation. Propensity to non-immunologic contact urticaria and objective irritation in stingers. Dermatosen 36, 45-49, 1988

(34) Schauder S, Schrader A, Ippen H: Göttinger Liste 1996. Sonnenschutzkosmetik in Deutschland. 4. Aufl., Blackwell Wissenschafts-Verlag, Berlin Wien 1996

(35) Fiedler HP, Ippen H, Kemper FH, Lüpke NP, Schulz KH, Umbach W (Hrsg.): Blaue Liste. Inhaltsstoffe kosmetischer Mittel. 2. Aufl., Editio Cantor Verlag, Aulendorf 1993

(36) Hannuksela M., Salo H.: The repeated open application test (ROAT). Contact Dermatitis 14, 221 - 227, 1986

10 Elaborated by

Dr. M. Arens-Corell, Sebapharma GmbH & Co., Boppard
Dr. G. Blume, ROVI GmbH, Schlüchtern
Dr. N. Chauvet, Vichy Pharma Kosmetik, Bruchsal
PD Dr. W. Czech, Hautarztpraxis, Villingen-Schwenningen
Prof. Dr. R. Daniels, Institut für Pharmazeutische Technologie,Technische Universität Carolo-Wilhelmina, Braunschweig
Prof. Dr. P. Elsner, Klinik für Hautkrankheiten, Friedrich-Schiller-Universität, Jena
Dr. J. Gassmüller, Institut Bioskin, Hamburg
Dr. P. Hansen, Stada R & D GmbH, Bad Vilbel
PD Dr. U. Heinrich, Institut für experimentelle Dermatologie, Universität Witten//Herdecke, Witten
Apothekerin U. Kindl, Margarethen-Apotheke, Baldham
Prof. Dr. H.C. Korting, Dermatologische Klinik, Ludwig-Maximillians-Universität, München
Dr. J. Kresken, Irmgardis-Apotheke, Viersen
Prof. Dr. J. Krutmann, Hautklinik, Heinrich-Heine-Universität, Düsseldorf
Prof. Dr. G. Kutz, Technologie der Kosmetika und Waschmittel, Fachhochschule Lippe, Lemgo
Dr. W. Leven, Eimsbütteler-Apotheke, Hamburg
Dr. B. Marschner, Hans Karrer GmbH, Königsbrunn
Dr. S. Meszaros, Pierre Fabre Dermo Kosmetik GmbH, Freiburg
Dr. W. Pittermann, Henkel KGaA, Düsseldorf
Apothekerin S. Poth, Redaktionsbüro, Wiesbaden
Apotheker L. Raunecker, Kranich-Apotheke, Kitzingen
Dr. F. Rippke, Beiersdorf AG, Hamburg
Dr. A. Schrader, Beratungslabor Dr. Schrader, Holzminden
PD Dr. N. Schürer, Hautarztpraxis, Würzburg
Dr. S. Wallat, Cognis Deutschland GmbH, Düsseldorf
Prof. Dr. V. Wienert, Hautklinik der Medizinischen Fakultät, Rheinisch-Westfälische Technische Hochschule, Aachen

The guidelines have been established on behalf of the GD Gesellschaft für Dermopharmazie by the a.m. expert group as a consensus paper.

Last revision: 17 February 2000
Planned next revision: January 2002

Reference:
The June 1999 version of these guidelines was published in:
Deutsche Apotheker Zeitung 139. Volume No. 24 (17 June 1999) pages 2397 - 2399

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