Depth-dependent hydration dynamics in human skin: Vehicle-controlled efficacy assessment of a functional 10% urea plus NMF moisturizer by near-infrared confocal spectroscopic imaging (KOSIM IR) and capacitance method complemented by volunteer perception.

BACKGROUND: Stratum corneum (SC) hydration is vital for the optimal maintenance and appearance of healthy skin. In this context, we evaluated the efficacy of an NMF-enriched moisturizer containing 10% urea on different aspects of SC hydration of dry skin. MATERIAL AND METHODS: In two clinical studies, the hydration efficacy of the moisturizer in comparison to its vehicle was investigated. In the first study, 42 subjects applied the moisturizer and the vehicle to one lower leg each. Thirty minutes and 24 h after this single treatment, SC hydration was measured by corneometry. Volunteers also rated skin moisturization and evaluated product properties. In the second study, 27 subjects each treated one forearm twice daily for 2 weeks with the moisturizer and the vehicle. Then, depth-resolved water-absorption spectra were measured by near-infrared confocal spectroscopic imaging (KOSIM IR). RESULTS: The moisturizer exerted a superior hydrating effect compared to the vehicle. KOSIM IR measurements show that, compared to the vehicle, the moisturizer significantly improved the water gradient in the SC from the surface to a depth of 15 µm. Moreover, the moisturizer received high acceptance ratings from the volunteers and was preferred to the vehicle. CONCLUSION: The humectants applied in the investigated moisturizer improved SC water content in total and as a function of depth. The combination of depth-resolved data (KOSIM IR) with classical corneometry provides an integrated concept in the measurement of skin hydration, rendering both methods complementary. These findings were in line with the volunteers` self-assessments of the moisturizer properties that are relevant to treatment adherence.

A Biomimetic Combination of Actives Enhances Skin Hydration and Barrier Function via Modulation of Gene Expression: Results of Two Double-Blind, Vehicle-Controlled Clinical Studies.

INTRODUCTION: Xerosis cutis is characterized by a decreased stratum corneum (SC) hydration and an impaired skin barrier function. Urea, the most prevalent natural moisturizing factor (NMF), is currently considered the gold standard. Its efficacy can further be increased by combining urea with other NMF and skin barrier lipids (SBLs). OBJECTIVE: We set out to evaluate physiological effects of a novel functional moisturizer containing 10% urea, additional NMF components, and a combination of SBLs on skin hydration and skin barrier integrity on a cellular and phenotypic level in female volunteers suffering from xerosis. METHODS: Two double-blind, vehicle-controlled clinical studies were conducted. In the first study, 44 female subjects having very dry body skin applied the moisturizer or its vehicle twice daily to their volar forearms. Twenty-four hours after a single product application as well as 24 h after 2 weeks of treatment, SC hydration was measured by corneometry. Skin barrier function was assessed by transepidermal water loss 24 h and 48 h after 2 weeks of regular use. Twenty-four hours after 2 weeks of application, skin tape stripping was performed, and urea content was determined in the 3rd strip by means of high-performance liquid chromatography/tandem mass spectrometry. In the second study, 22 women with self-reported very dry skin applied the moisturizer or vehicle twice daily to their volar forearms for 2 weeks. Then, suction blister samples were obtained for gene expression analysis using RT-PCR. RESULTS: Application of the actives led to significantly improved skin hydration and barrier function at all points in time. Compared to the vehicle, application of the moisturizer for 2 weeks resulted in a significant increase in SC urea content. Relative gene expression data revealed significant upregulation of genes associated with skin barrier function, hydration, differentiation, and lipid metabolism compared to the vehicle-treated area. CONCLUSIONS: Overall, our data demonstrate that the functional moisturizer provides an adequate bioavailability of urea and a beneficial biophysical impact on xerotic skin. Topical treatment with a combination of urea and additional NMF as well as SBL can modify mRNA expression of important epidermal genes stimulating cellular processes and functions. The well-tolerated novel functional moisturizer stimulates molecular mechanisms involved in skin hydration and barrier function and is a profoundly effective treatment option for xerosis cutis.

Multidirectional activity of bakuchiol against cellular mechanisms of facial ageing - Experimental evidence for a holistic treatment approach.

OBJECTIVE: Skin ageing is a multifactorial process involving formation of reactive oxygen species, consecutive inflammation with reduced epidermal and dermal cell viability and resulting damage to the extracellular matrix. Effective dermocosmetic treatment modalities should ideally address these hallmarks in a holistic approach. Here, we determined the corresponding activity profile of bakuchiol, a plant-derived meroterpene, in an array of in vitro, ex vivo and in vivo studies and compared it to retinol, currently considered as gold standard in topical antiageing cosmetics. METHODS: The antioxidative capacity and power of bakuchiol and retinol were analysed by measuring 2,2'-diphenyl-1-picrylhydrazyl (DPPH) reduction via its absorption decay and electron spin resonance spectroscopy, respectively. Effects on prostaglandin E2 (PGE2), macrophage migration inhibitory factor (MIF), fibroblast growth factor 7 (FGF7), collagen type I and VII (COL1A1, COL7A1), fibronectin (FN) levels as well as the metabolization of water-soluble tetrazolium 1 (WST-1) were determined in human dermal fibroblasts. Epidermal regeneration was assessed utilizing an in vitro wound healing model. FN protein levels were analysed ex vivo after treatment with a formulation containing bakuchiol, retinol or vehicle using suction blister fluid. Skin condition improvement was determined in vivo in a split-face comparison study after application of bakuchiol or vehicle. RESULTS: In contrast to retinol, bakuchiol demonstrated high antioxidative efficacy. Levels of PGE2 and MIF were significantly decreased by both bakuchiol and retinol. Bakuchiol but not retinol significantly increased FGF7 protein levels. WST-1 metabolization levels were significantly augmented by bakuchiol and retinol. Bakuchiol and retinol application led to a significant augmentation of COL1A1, COL7A1 and FN protein levels. Wounds supplemented with bakuchiol but not retinol displayed a significant increase in epidermis regeneration. Clinically, areas treated with a bakuchiol-containing formulation showed a statistically significant increase in FN protein values after a 4-week application compared to untreated areas and areas treated with vehicle. CONCLUSION: These data provide evidence for the multidirectional efficacy of bakuchiol against cellular hallmarks of skin ageing. Its activity profile shares some common features with retinol but demonstrates several hitherto unknown biopositive effects in our studies, namely stimulation of the critical extracellular matrix component FN, and accelerated epidermal regeneration and wound healing.

OBJECTIF: le vieillissement de la peau est un processus multifactoriel impliquant la formation de dérivés réactifs de l'oxygène, une inflammation consécutive qui entraîne une viabilité réduite des cellules du derme et de l'épiderme, et endommage la matrice extracellulaire. Pour être efficaces, les traitements dermocosmétiques devraient dans l'idéal traiter ces caractéristiques selon une approche holistique. Ici, nous avons déterminé le profil d'activité correspondant du bakuchiol, un méroterpène d'origine végétale, dans une série d'études in vitro, ex vivo et in vivo, et l'avons comparé au rétinol, qui est aujourd'hui considéré comme la référence parmi les cosmétiques anti-âge topiques. MÉTHODES: la capacité antioxydante et la puissance du bakuchiol et du rétinol ont été analysées en mesurant la réduction du 2,2-diphényl-1-picrylhydrazyl (DPPH) selon sa décroissance par absorption et à l'aide d'une spectroscopie par résonance magnétique électronique, respectivement. Les effets sur la prostaglandine E2 (PGE2), le facteur inhibiteur de la migration (FIM) des macrophages, le facteur de croissance des fibroblastes 7 (FGF7), le collagène de type I et VII (COL1A1, COL7A1), les taux de fibronectine (FN), ainsi que la métabolisation du tétrazolium 1 soluble dans l'eau (WST-1) ont été déterminés dans des fibroblastes dermiques humains. La régénération épidermique a été évaluée à l'aide d'un modèle de cicatrisation des plaies in vitro. Les taux de fibronectine ont été analysés ex vivo après un traitement avec une formulation contenant du bakuchiol, du rétinol ou un excipient à l'aide d'un liquide d'aspiration sous forme de vésicules. L'amélioration de l'état de la peau a été déterminée in vivo dans une étude de comparaison en hémiface après l'application de bakuchiol ou d'un excipient. RÉSULTATS: Contrairement au rétinol, le bakuchiol s'est avéré présenter une efficacité antioxydante élevée. Les taux de PGE2 et de FIM ont significativement diminué avec le bakuchiol et le rétinol. L'application de bakuchiol s'est accompagnée d'une augmentation significative des taux de protéine FGF7, mais pas celle de rétinol. Les taux de métabolisation du WST-1 ont augmenté de façon significative avec le bakuchiol et le rétinol. L'application de bakuchiol et de rétinol a entraîné une augmentation significative des taux de protéines COL1A1, COL7A1 et fibronectine. Les plaies supplémentées en bakuchiol, mais pas en rétinol, ont montré une augmentation significative de la régénération épidermique. Sur le plan clinique, les zones traitées avec une formulation contenant du bakuchiol ont montré une augmentation statistiquement significative des taux de fibronectine après une application de 4 semaines par rapport aux zones non traitées et aux zones traitées avec un excipient. CONCLUSION: ces données fournissent des preuves de l'efficacité multidirectionnelle du bakuchiol contre les caractéristiques cellulaires du vieillissement de la peau. Son profil d'activité partage certaines caractéristiques communes avec le rétinol, mais démontre plusieurs effets biopositifs jusqu'alors inconnus dans nos études : la stimulation de la fibronectine, composante essentielle de la matrice extracellulaire, et une régénération épidermique et une cicatrisation accélérée des plaies.

High-energy visible light at ambient doses and intensities induces oxidative stress of skin-Protective effects of the antioxidant and Nrf2 inducer Licochalcone A in vitro and in vivo.

BACKGROUND: Solar radiation causes skin damage through the generation of reactive oxygen species (ROS). While UV filters effectively reduce UV-induced ROS, they cannot prevent VIS-induced (400-760 nm) oxidative stress. Therefore, potent antioxidants are needed as additives to sunscreen products. METHODS: We investigated VIS-induced ROS formation and the photoprotective effects of the Nrf2 inducer Licochalcone A (LicA). RESULTS: Visible spectrum of 400-500 nm dose-dependently induced ROS in cultured human fibroblasts at doses equivalent to 1 hour of sunshine on a sunny summer day (150 J/cm2 ). A pretreatment for 24 hours with 1 µmol/L LicA reduced ROS formation to the level of unirradiated cells while UV filters alone were ineffective, even at SPF50+. In vivo, topical treatment with a LicA-containing SPF50 + formulation significantly prevented the depletion of intradermal carotenoids by VIS irradiation while SPF50 + control did not protect. CONCLUSION: LicA may be a useful additive antioxidant for sunscreens.

Stand-alone Emollient Treatment Reduces Flares After Discontinuation of Topical Steroid Treatment in Atopic Dermatitis: A Double-blind, Randomized, Vehicle-controlled, Left-right Comparison Study.

Prevention of the flares is a main goal in the long-term treatment of atopic dermatitis (AD). Therefore we investigated the efficacy of a water-in-oil emollient, containing licochalcone A, omega-6-fatty acids, ceramide 3 and glycerol, for prevention of the flares in adults with mild to moderately severe AD, treated with topical steroids, that led to clearing of the inflammatory lesions and had been discontinued prior to inclusion. The study was a 12-week, double-blind, randomized, vehicle-controlled, left-right comparison test with the number of relapses, defined as re-occurrence of erythema for at least 3 consecutive days, considered the primary outcome. Compared with the vehicle, the active formulation significantly reduced the number of relapses and maintained the barrier homeostasis of the respective arm. To the best of knowledge, this is the first study to show prevention of the AD flares by the use of stand-alone emollient treatment, based on comparison with the corresponding vehicle while excluding concomitant/rescue medications.

Impact of a pH 5 Oil-in-Water Emulsion on Skin Surface pH.

BACKGROUND: Human skin surface has a physiologically acidic pH (pHss). In cases of increased pHss, the acidity of the skin can be restored by topical formulations. We tested a pH 5 oil-in-water (O/W) emulsion for pHss regeneration and stabilization. METHODS: We performed 2 experiments with 10 female study subjects in each. In both experiments, 2D imaging with luminescent sensor foils was used to determine pHss. Alkalization was reached by washing the volar forearm with a soap bar and warm running tap water for 20 min. Experiment 1: after defining the baseline pHss, we alkalized the respective area and measured pHss over a duration of 5 h, while applying emulsion every hour. Experiment 2: study subjects used the emulsion twice daily for 1 week. Then, pHss was measured before and after 5 min of washing a treated and an untreated area on the volar forearm. RESULTS: (1) 5 h after alkalization, the treated arm showed a significantly lower pHss than the untreated one (5.87 ± 0.03 vs. 6.05 ± 0.03); (2) after washing, the treated area had a significantly lower pHss than controls (6.13 ± 0.03 vs. 6.27 ± 0.05). CONCLUSIONS: The tested pH 5 O/W emulsion seems to improve regeneration and stabilization of pHss.

Prevention of Cutaneous Penetration and CD1c+ Uptake of Pollen Allergens by a Barrier-Enhancing Formulation.

Recent studies have shown that pollen proteins can penetrate the impaired skin barrier of atopic patients and exacerbate their disease. In the presented study the effect of a topically applied barrier-enhancing formulation was investigated for its preventive effect on the uptake of pollen allergens into CD1c+ epidermal cells. The pollen proteins were fluorescence labelled and applied on barrier-disrupted excised human skin. CD1c+ cells were selected after magnetic cell sorting and analysed using laser scanning microscopy. In untreated disrupted skin, 81% of the CD1c+ cells contained the fluorescence-labelled pollen allergens. In formulation-pretreated skin only 12% of the CD1c+ cells showed an uptake of pollen allergens. These results encourage the treatment of atopic patients with barrier-enhancing formulations to reduce the impact of pollen on air-exposed skin areas and hence the exacerbation of cutaneous symptoms.

Steroid-Free Over-the-Counter Eczema Skin Care Formulations Reduce Risk of Flare, Prolong Time to Flare, and Reduce Eczema Symptoms in Pediatric Subjects With Atopic Dermatitis.

INTRODUCTION: Atopic dermatitis (AD) is a chronic skin condition associated with decreased barrier function resulting in periodic flare-ups of erythematous and pruritic lesions. Guidelines recommend daily treatment of atopic skin with emollient moisturizers for prevention of flares and maintenance of the flare-free state. This study evaluated the efficacy of 2 steroid-free, nonprescription eczema skin care formulations for reducing the risk of flare and relieving symptoms in infants and children with AD: Body Cream for the daily maintenance treatment of atopic skin and Flare Treatment for the treatment of atopic flares. METHODS: After a 2-week washout period, subjects (N=45; mean age 3.5 years) were randomized to cleanser plus daily moisturizing with Body Cream (moisturizer group) or cleanser only (control group) for 6 months or until flare. Subjects experiencing flare received Flare Treatment for 4 weeks. RESULTS: The incidence of flare was significantly lower in the moisturizer group compared with the control group (21% vs 65%; P=.006), while the median time to flare was shorter in the control group (28 vs >180 days). Risk of flare was reduced by 44.1% after 6 months of Body Cream application. Flare Treatment reduced overall eczema symptom severity at week 2 and week 4; 78.9% of flares had improved or cleared at week 4. CONCLUSIONS: Body Cream reduced the incidence of flare and the time to flare, reinforcing guidelines that daily emollient therapy should be an integral part of the maintenance treatment plan for the prevention of disease flares. Body Cream and Flare Treatment are effective over-the-counter steroid-free options for management of AD in children.

Steroid-free emollient formulations reduce symptoms of eczema and improve quality of life.

Two over-the-counter products have been clinically tested for efficacy and tolerability in the treatment of atopic dermatitis. Study 1 evaluated a daily maintenance Body Cream (Eucerin Eczema Relief Body Crème) applied twice daily for 14 days, followed by treatment withdrawal for 5 days (regression period) in subjects with a history of atopic dermatitis. Study 2 evaluated an acute treatment (Eucerin Eczema Relief Instant Therapy [Instant Therapy]) for active atopic dermatitis lesions administered for 14 days. Skin barrier function, hydration, tolerability, and relief of symptoms were assessed at baseline, day 7, and day 14. Study 2 also measured itch relief and treatment impact on work, social activities, and sleep. Body Cream significantly improved skin hydration and barrier function (P<.001) at 14 days, with improvements persisting through the 5-day regression phase. Itching was significantly improved in 93.8% of subjects (P<.001). Instant Therapy treatment of atopic dermatitis lesions significantly improved skin hydration and barrier function, as well as symptoms of erythema, pruritus, excoriation, and lichenification, with rapid improvement of itch reported within minutes of the first treatment application. Instant Therapy significantly reduced itch intensity and frequency, and demonstrated beneficial improvements in subjects' quality of life. Body Cream and Instant Therapy were both safe and well tolerated.

Efficacy of a new tonic containing urea, lactate, polidocanol, and glycyrrhiza inflata root extract in the treatment of a dry, itchy, and subclinically inflamed scalp.

BACKGROUND/AIMS: Dry, itchy and inflamed scalp conditions are common and often associated with diseases such as atopic dermatitis or psoriasis. To improve these symptoms, we investigated the efficacy of a new tonic containing the active ingredients urea, lactate, polidocanol, and Glycyrrhiza inflata root extract, containing licochalcone A. STUDY DESIGN/METHODS: 30 subjects with dry and itchy scalp conditions underwent a randomized half-head study for 4 weeks, applying the leave-on tonic three times a week on one side of the scalp. Tonic effects on skin hydration, itching, lipids, microinflammation, and substantivity of tonic compounds were determined using corneometry, middle-infrared spectroscopy, direct analysis in real-time mass spectrometry, and enzyme-linked immunosorbent assay. Volunteers performed a self-assessment; changes in scalp condition were documented by in vivo microscopy. RESULTS: After tonic treatment, scalp moisture was significantly increased, whereas scalp itching and tautness were significantly reduced. Results also demonstrated a high substantivity of urea and lactate on the scalp, an increase in triglyceride, and a decrease in free fatty acid levels. The amount of total lipids was unchanged. Analyses of scalp wash-ups verified a significant reduction in important pro-inflammatory markers. CONCLUSION: Due to the actives urea, lactate, polidocanol, and the anti-inflammatory licochalcone A, the new scalp tonic exhibited excellent performance in alleviating scalp dryness, itching, microinflammation, and in normalizing disturbances of scalp lipids.

Efficacy of Nonprescription Moisturizers for Atopic Dermatitis: An Updated Review of Clinical Evidence.

Twice-daily moisturization is recommended by international guidelines as the bedrock of the management of atopic dermatitis (AD). Moisturizers should be selected based on proven clinical effectiveness in improving the skin barrier and improving the symptoms of AD. We searched the PubMed database for clinical trials assessing daily moisturization for the treatment of AD published between 2006 and 2019. Studies had to assess the efficacy of commercially available moisturizers using objective measures of corneometry, transepidermal water loss, or incidence of flare as endpoints, and treatments had to be currently available to patients. Clinical studies showed that moisturization (typically twice daily) significantly improved the skin barrier in adults and children with AD. Longer-term flare studies showed that daily moisturization reduced the incidence of flares and extended the time between flares. Proactive moisturization of infants at high risk of developing AD may reduce its manifestation. Therapeutic moisturizers for AD are specifically formulated with ingredients that target symptoms of AD, such as itch, inflammation, or compromised skin barrier. The US FDA requires that any moisturizer available in the USA and claiming to treat AD must contain colloidal oatmeal. Healthcare providers can maximize compliance and outcomes by educating patients on the benefits of liberally applying a therapeutic moisturizer twice daily to support the skin barrier and help reduce the incidence of flares. Specific recommendations should be for clinically tested moisturizers evaluated using objective, validated skin assessments.

pH and Microbial Infections.

Maintenance of an acidic stratum corneum pH is a major component of the skin's protective system and creates a hostile environment for colonization with pathogenic microorganisms. This barrier can however be overcome on healthy and in particular on compromised skin. Mycosis, diaper/incontinence dermatitis and wound healing are examples of cases where microbial infection is promoted by the altered skin conditions or environment. Fungi have a complex system that senses ambient pH that leads to metabolic responses allowing adhesion, growth and invasion, as microbial metabolites further increase skin pH resulting in a clinically manifest infection (mycosis). Diabetic patients with a higher pH in intertriginous areas are particularly vulnerable to candidiasis. In diaper and incontinence dermatitis, the increase in skin pH and damage to the skin barrier function is triggered by the contact with urine and faeces with or without occlusion and maintained by host and microbial enzymes and metabolites. This leads to the reduction of the protective resident microflora and fungal overgrowth, mostly with Candida albicans. Skin care with slightly acidic products may help to prevent and treat this kind of dermatitis. Wound healing is a complex sequence of biologic events correlated with ambient pH, which influences the different phases of the healing process. The pH determines the appropriate activity of immune cells and key enzymes as well as biofilm formation. Chronic wounds emerging from the disruption of the healing process are characterized by a neutral to slightly alkaline pH and may benefit from wound pH monitoring and therapeutic acidification.

Highly efficient and compatible shampoo for use after hair transplant.

BACKGROUND: Sensitive or hyperreactive skin is a common condition defined by prickling, burning, pain, and pruritus. Although this skin problem was initially described on the face, the scalp is often affected. A sensitive scalp can react with irritation to harsh surfactants or other additives which are often present in shampoos. For this reason, we developed a new rinse-off hypertolerant shampoo specifically designed for the hypersensitive and problematic scalp. METHODS: The shampoo formulation is based on an extremely mild surfactant system and contains bisabolol, an anti-irritant and anti-inflammatory ingredient of chamomile. The shampoo is free of additives such as perfumes, silicones, colorants, parabens, paraffins, and betaine. Since skin can remain in a hyperreactive state after wounding, the status after hair transplantation was chosen as a model system to test the shampoo. Scalp condition and compatibility of each volunteer were analyzed by a plastic surgeon directly after hair transplant and after stitch removal. The plastic surgeons also rated whether they would recommend the further use of the test shampoo. Additionally, volunteers completed a self-assessment questionnaire. RESULTS: Following hair transplantation, regular use of the shampoo resulted in a significant reduction in the extent of scabbing and erythema. This was confirmed by dermatological scalp examinations performed by the plastic surgeon as well as in volunteers' self-assessments. The plastic surgeon highly recommended the further use of the test shampoo after hair transplant to all study participants. CONCLUSION: Application of the test shampoo demonstrated excellent skin compatibility and product efficacy after hair transplant. The test shampoo significantly reduced the extent of scabs and erythema. Therefore, the shampoo is ideally suited for use after hair transplantation and for the treatment of sensitive scalp. The excellent skin compatibility is because of the mild surfactant system, the calming ingredient bisabolol, and the absence of potentially irritating ingredients.

Birch pollen influence the severity of atopic eczema - prospective clinical cohort pilot study and ex vivo penetration study.

There is little clinical evidence for a correlation between the severity of atopic eczema (AE) and pollen exposition. To obtain more data, we performed a clinical cohort pilot study about the influence of pollen on AE between sensitized and nonsensitized subjects and an experimental study addressing the cutaneous penetration of pollen into the skin. Fifty-five patients were monitored during birch pollen season. To study the cutaneous penetration, grass pollen allergens were applied on excised skin and the uptake in CD1c-expressing dendritic cells was investigated. The correlation between environmental pollen load and severity of the Scoring Atopic Dermatitis (SCORAD) score and pruritus was observed, regardless of the status of sensitization. The sensitized group recovered significantly worse after the birch pollen season. Remarkably higher amounts of pollen allergens taken up by CD1c cells were detected in epidermal cells derived from skin explants with a disturbed epidermal barrier. These findings suggest an exacerbating role of pollen in AE utilizing the epidermal route.

The acidic milieu of the horny layer: new findings on the physiology and pathophysiology of skin pH.

The acidic pH of the horny layer, measurable on the skin surface, has long been regarded as a result of exocrine secretion of the skin glands. The 'acid mantle' was thought to regulate the bacterial skin flora and to be sensitive primarily to skin cleansing procedures. In recent years, an increasing number of investigations have been published on the changes in, and constituents and functions of, the pH of the deeper layers of the stratum corneum, as well as on the influence of physiological and pathological factors. A central role for the acidic milieu as a regulating factor in stratum corneum homeostasis is now emerging. This has relevance to the integrity of the barrier function, from normal maturation of the stratum corneum lipids through to desquamation. Changes in the pH and the organic factors influencing it appear to play a role, not only in the pathogenesis, prevention and treatment of irritant contact dermatitis, but also of atopic dermatitis and ichthyosis and in wound healing. On the basis of these findings, a broader concept, exceeding the superficial 'acid mantle' theory, has been formulated.

Topical use of dexpanthenol in skin disorders.

Pantothenic acid is essential to normal epithelial function. It is a component of coenzyme A, which serves as a cofactor for a variety of enzyme-catalyzed reactions that are important in the metabolism of carbohydrates, fatty acids, proteins, gluconeogenesis, sterols, steroid hormones, and porphyrins. The topical use of dexpanthenol, the stable alcoholic analog of pantothenic acid, is based on good skin penetration and high local concentrations of dexpanthenol when administered in an adequate vehicle, such as water-in-oil emulsions. Topical dexpanthenol acts like a moisturizer, improving stratum corneum hydration, reducing transepidermal water loss and maintaining skin softness and elasticity. Activation of fibroblast proliferation, which is of relevance in wound healing, has been observed both in vitro and in vivo with dexpanthenol. Accelerated re-epithelization in wound healing, monitored by means of the transepidermal water loss as an indicator of the intact epidermal barrier function, has also been seen. Dexpanthenol has been shown to have an anti-inflammatory effect on experimental ultraviolet-induced erythema. Beneficial effects of dexpanthenol have been observed in patients who have undergone skin transplantation or scar treatment, or therapy for burn injuries and different dermatoses. The stimulation of epithelization, granulation and mitigation of itching were the most prominent effects of formulations containing dexpanthenol. In double-blind placebo-controlled clinical trials, dexpanthenol was evaluated for its efficacy in improving wound healing. Epidermal wounds treated with dexpanthenol emulsion showed a reduction in erythema, and more elastic and solid tissue regeneration. Monitoring of transepidermal water loss showed a significant acceleration of epidermal regeneration as a result of dexpanthenol therapy, as compared with the vehicle. In an irritation model, pretreatment with dexpanthenol cream resulted in significantly less damage to the stratum corneum barrier, compared with no pretreatment. Adjuvant skin care with dexpanthenol considerably improved the symptoms of skin irritation, such as dryness of the skin, roughness, scaling, pruritus, erythema, erosion/fissures, over 3 to 4 weeks. Usually, the topical administration of dexpanthenol preparations is well tolerated, with minimal risk of skin irritancy or sensitization.

Stratum corneum pH in atopic dermatitis: impact on skin barrier function and colonization with Staphylococcus Aureus.

Recent studies have provided new insights into the occurrence, causes, and pathogenetic consequences of changes in the skin pH in atopic dermatitis, particularly with respect to skin barrier function and colonization with Staphylococcus aureus. Growing evidence suggests an impaired release of proton donors, such as amino acids, urocanic acid, and lactic acid, to the stratum corneum in atopic dermatitis, as a result of reductions in filaggrin proteolysis and sweat secretion. In addition, an impaired formation of free fatty acids from sebaceous lipids and epidermal phospholipids seems to be involved. Because both lipid organization and lipid metabolism in the stratum corneum requires an acidic pH, these alterations might contribute to the disturbance of skin barrier function observed in atopic dermatitis. Furthermore, bacterial growth and virulence of S. aureus, as well as defensive host mechanisms, have increasingly been delineated as pH dependent, giving rise to a new understanding of the pathophysiology underlying increased skin colonization seen in atopic dermatitis.

The hair strand test - a new method for testing antifungal effects of antidandruff preparations.

Seborrheic dermatitis and its minimal variant, dandruff (pityriasis simplex capillitii), are among the most frequent diseases caused by Malassezia (M.) yeasts. Treatment studies have shown that antimycotics achieve clinical improvement, while recolonization leads to recurrent symptoms. Among the antimycotics used are azoles, hydroxypyridones, and various agents such as zinc pyrithione, tar, and selenium disulfide. However, comparative efficacy studies in vitro should not only consider the minimal inhibitory concentrations against Malassezia yeasts but also the bioavailability of the individual substances with regard to hair and scalp. By means of a new method, the hair strand test, hairs from ten volunteers were subjected to standardized 5-min incubation with different shampoo formulations. Thereafter they were rinsed with running water for 1 min and dried. Two hundred each of these hairs (length 1 cm) were given into a medium (olive oil on selective agar for pathogenic fungi) inoculated with M. sympodialis or M. globosa (5 x 10(3) CFU/microl), and the influence on growth was semiquantitatively determined over a period of up to 18 days. According to preliminary results, 1% climbazole proved to be particularly effective. The hair strand test, which can also be performed ex vivo, is a new method to find out whether antimycotic agents bind differently to the hair substance and, via a depot effect, may influence the growth of Malassezia yeasts and thus affect dandruff. This allows conclusions about the efficacy of antidandruff formulations.

Treatment of xerosis with a topical formulation containing glyceryl glucoside, natural moisturizing factors, and ceramide.

OBJECTIVE: To assess the effects of Light Formulation, an oil-in-water emulsion, and Rich Formulation, a water-in-oil emulsion, for the treatment of xerosis. DESIGN: Two double-blind, vehicle-controlled trials (both formulations); a double-blind, randomized regression study (Rich Formulation); and a single-blind tolerability study (Light Formulation). The two formulations were applied twice daily for two weeks, for five days in the regression study, and twice daily for two weeks in the tolerability study. SETTING: Studies were conducted during winter in Hamburg, Germany. PARTICIPANTS: A total of 169 subjects were enrolled and 154 completed the studies. The majority were between 50 and 80 years of age, women, all with very dry skin. One withdrew because of an incompatibility reaction that reoccurred with the subject's own body lotion after sun exposure. MEASUREMENTS: Skin hydration and skin barrier function with both formulations over two weeks, long-term moisturization effect after discontinuation of Rich Formulation, and symptom improvement and skin tolerability with Light Formulation. RESULTS: Vehicle-controlled studies of Light and Rich Formulations demonstrated significantly improved hydration at Weeks 1 and 2 versus the untreated site and vehicles, and significantly reduced transepidermal water loss versus untreated site and basic vehicle. Both products significantly decreased visible dryness and tactile roughness. In the regression study, Rich Formulation maintained significant moisturization six days after treatment discontinuation. Light Formulation reduced symptoms of itching, burning, tightness, tingling, and feeling of dryness. CONCLUSION: These formulations represent a new approach for the treatment of xerosis by addressing multiple key deficiencies in skin hydration.