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.

Thiamidol containing treatment regimens in facial hyperpigmentation: An international multi-centre approach consisting of a double-blind, controlled, split-face study and of an open-label, real-world study

Objective

Tyrosinase is the rate‐limiting enzyme in melanogenesis. Thiamidol is the most potent inhibitor of human tyrosinase out of 50 000 tested compounds. In clinical studies, it was shown to improve facial hyperpigmentation, post‐inflammatory hyperpigmentation and age spots significantly. To identify the optimal number of daily Thiamidol applications, we conducted a split‐face study comparing the efficacy and tolerability of four‐times with two‐times daily application. Subsequently, we evaluated the efficacy and tolerability of a typical face care regimen containing Thiamidol in a real‐world study.

Methods

The split‐face study was double‐blind, randomized, controlled, including two Thiamidol containing products (serum and day care SPF 30). The serum was applied twice daily on one half of the face and the day care SPF30 twice‐daily on the whole face. The real‐world study was open‐label, observational, including three Thiamidol containing products (day care SPF 30 in the morning, serum and night care in the evening). In both studies, subjects with mild‐to‐moderate facial hyperpigmentation applied the products over 12 weeks. Assessments included clinical and subjective grading of hyperpigmentation, skin condition, hemi‐/modified MASI, chromameter and clinical photography.

Results

In the split‐face study (n = 34), hyperpigmentation, skin roughness and hMASI improved all significantly (P < 0.001) versus baseline, with first visible results after two weeks of twice‐daily application. The four‐times daily application led to significant improvement versus the two‐times daily application. In the real‐world study (n = 83), all evaluated parameters, including skin condition and chromametry (n = 30), improved significantly (P < 0.001) in comparison with baseline and the corresponding preceding visits. The subjects judged the cosmetic properties of the products positively. In both studies, the products were well tolerated.

Conclusion

Four‐times daily Thiamidol improves facial hyperpigmentation significantly more than two‐times daily and is well tolerated by the subjects. The real‐world study with a typical face care regimen containing Thiamidol shows improvement of facial hyperpigmentation and confirms tolerability. Furthermore, the data provide evidence for the suitability of this three‐product Thiamidol regimen for day‐to‐day life.

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.

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.

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%; <em>P</em>=.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.

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.

Topical activity of ascorbic acid: from in vitro optimization to in vivo efficacy

We present here a new cosmetic formula system containing 3% ascorbic acid based on an optimized oil-in-water (O/W) emulsion. This formulation demonstrated a good long-term stability of the active ingredient and also of the emulsion itself. It could be deduced from in vitro release studies that this O/W emulsion enabled a better release of the hydrophilic active agent than an alternative W/O emulsion. By measuring the ultraweak photon emission, which is a well-established parameter for the oxidative stress in the skin, the high in vivo antioxidant capacity of 3% ascorbic acid was demonstrated after 1 week of product application. This placebo-controlled study also proved that ascorbic acid in an O/W cream reduced oxidative stress in human skin significantly better than the derivative sodium ascorbyl-2-phosphate, a more stable vitamin C replacement commonly used in cosmetic formulations. With increasing age, the number of papillae in the epidermal-dermal junction zone in human skin are reduced. This implies a possible consequence of reduced mechanical resistance of the skin and impaired supply of the epidermis with nutrients. In a 1-month placebo-controlled study on 25 human volunteers, a significant increase in the number of dermal papillae after application of the 3% ascorbic acid cream was demonstrated, using a confocal laser scanning microscope. Fine lines and wrinkles are a characteristic sign of aged and especially photo-aged skin. Application of 3% ascorbic acid in a 12-week placebo-controlled usage study indicated a significant reduction of facial wrinkles. Altogether, 3% ascorbic acid in a cosmetic O/W emulsion has been shown to be appropriately stable and to enable a good release of the active agent in vitro as a precondition for a high efficacy in vivo. Application in vivo resulted in a significant reduction of oxidative stress in the skin, an improvement of the epidermal-dermal microstructure and a reduction of fine lines and wrinkles in aged skin. These results were received within a relatively short period of time of product application.

Hepatic gene expression patterns in thyroid hormone-treated hypothyroid rats

Thyroid hormone (T3) is essential for normal development, differentiation and metabolic balance. We have performed DNA microarray experiments using hepatic RNA from hypothyroid and T3-treated hypothyroid rats in order to characterize T3-induced gene expression patterns after various time points (6, 24 and 48 h after the administration of the hormone). Sixty-two of 4608 different genes displayed a reproducible T3-response, and cluster analysis divided these differentially regulated genes into six expression patterns. Thirty-six genes were not significantly regulated within the first 24 h. Transient transfection experiments of eight late-induced gene promoters failed to detect a thyroid hormone response element within their regulatory elements, suggesting an indirect activation mechanism(s). In search for an intermediate factor of T3 action, we examined whether various rather ubiquitous transcription factors, peroxisome proliferator-activated receptors (PPARs) and coactivators of the PPARgamma coactivator 1 family (PGC-1) are regulated by T3. Only PPARgamma and PERC/PGC-1beta exhibit a significant T3-response within the first 6 h after treatment, identifying these factors as candidate components for mediating the late-induced expression pattern. Regulation of early-induced genes within the first 6 h after administration of T3 on transcript levels correlates with altered protein levels after 24 and 48 h in vivo.

Anti-inflammatory efficacy of topical preparations with 10% hamamelis distillate in a UV erythema test

In 40 volunteers the efficacy of three lotions with 10% hamamelis distillates from different suppliers, two vehicles, dimethindene maleate 0.1% gel, hydrocortisone 1% cream and hydrocortisone 0.25% lotion were investigated in a modified UV erythema test with three UV dosages (1.2, 1.4 and 1.7 MED). The test preparations were applied occlusively over a 48-hour period following irradiation. Chromametric measurement of redness and visual assessment were performed 24, 48 and 72 h after induction of erythema. The hydrocortisone formulations were most effective in erythema suppression. An anti- inflammatory effect was noted for all three hamamelis lotions as well as for the vehicles. A significantly greater suppression of erythema than seen with the vehicles was noted for one of the hamamelis lotions at 1.4 MED. The efficacy of the antihistamine dimethindene maleate did not surpass the hamamelis lotions or the vehicles. Even though the differences between the hamamelis lotions were slight, it was possible to make an objective selection of the best hamamelis distillate for aftersun purposes.