Background Human life is based on oxygen respiration and an enzymatic, free radical-dependent water chemistry, whose billions of parallel reactions take place at pH ∼7.4 and a temperature of 37°C, in accordance with the laws of chemistry. The cellular metabolic processes occur over time periods covered by the half-lives of ROS (reactive oxygen species) for °OH to over 10 s for LOS (lipid oxygen species), indicating that mixtures of free radicals form the basic components for these processes. Summary and Key Messages The main source of radicals is the mitochondrial conversion of 1-5 % oxygen into "primary" ROS and "secondary" LOS. Every endogenous and exogenous radical generation, triggered by "natural background radiation", "natural environment" or "solar radiation" leads to qualitatively similar mixtures of "primary" ROS and "secondary" LOS or RNS (reactive nitrogen species). A Multilevel Antioxidant Regulation, Repair and Protection System (MARRPS) keeps these radical mixtures in a steady state. Depending on the total number of free radicals, different areas of radical action are defined. The Free Radical Ground State (FRGS) with "homeostasis" and "adaptive homeostasis", the Free Radical Threshold Value (FRTV) and Free Radical Pathological Conditions (FRPC). The quantitative ratio ROS > LOS comprehensively characterizes the "homeostasis" and "adaptive homeostasis" area of the FRGS. The total number of free radicals cannot be measured directly in the "homeostasis" area. "Adaptive homeostasis" is achieved when excess radicals are stable produced beyond "homeostasis" of the FRGS. The quantity that remains controllable in this range is a maximum of ∼3.58 10¹² radicals/mg, the value of the body constant FRTV. The sensitized MARRPS provides "semi-stable homeostatic" states characterized by dual stability with ROS > LOS and a stable total ROS/LOS and RNS count beyond the basal FRGS "homeostasis". If the total number of all radicals exceeds the FRTV, where LOS > ROS, this initiates uncontrolled radical chain reactions. The partial failure of the MARRPS in the FRPC area leads to pathological processes which are the starting point for a hundred different diseases. The design principle described by this simple model applies universally to all aerobic life.

When vitamin derivatives penetrate the epidermis, they release active compound such as ascorbic acids (AsA) and tocopherols via enzymatic digestion of chemical modifiers. To determine the transdermal penetration of the derivatives, the total permeation of both the derivatives and their active compounds that released from the derivatives should be considered. In this study, we established a skin penetration test method using a cultured, reconstructed skin model with active epidermal enzymes. And we analyzed two vitamin derivatives with different chemical properties: magnesium ascorbyl phosphate (APM) and sodium tocopheryl phosphate (TPNa), both of which has been confirmed their skin permeation in the reconstructed models and the digestion to AsA and α-tocopherol by the epidermal enzymes, respectively.

Topical therapy has been a fundamental part of dermatology, evolving from early ointments to advanced transdermal treatments. These formulations allow for effective management of skin conditions by maximizing local drug delivery and minimizing systemic effects. Modern topical therapies continue to benefit from innovations that improve both efficacy and patient outcomes.

Three interrelated skin water assessments include stratum corneum hydration (SCH) via electrical measurements, skin water using tissue dielectric constant (TDC) measurements, and transepidermal water loss (TEWL). These are differentially used for skin physiology research, clinical assessments of dermatological conditions and to assess skin water in diabetes and lymphedema. Often volar forearm skin is used for assessments done at various times of day (TOD). The present goal was to assess the extent of intraday variability in SCH, TDC, and TEWL.

Skin-blanching assay has been established as a surrogate method for assessing bioequivalence of topical corticosteroids. This study aimed to apply the skin-blanching assay to evaluate the bioequivalence of a test desonide cream (T) compared with the reference Desonide® (R) using Chinese skins. Additionally, the pharmacokinetics and safety profiles were also assessed.

Identifying subgroups of patients with primary hyperhidrosis (PHH) can improve the understanding of the disease pathophysiology. The study objective was to determine the naturally occurring subgroups of patients with PHH based on clinical characteristics.

Atopic dermatitis (AD) is a physical, emotional, and social burden for patients. Most suffer from itching, pain, and dry skin as well as sleep disturbances, experienced stigmatization, anxiety, or depression. Therefore, it is important to consider the psychosocial well-being and also stigmatization in the treatment of people with AD. The aims of this study were to compare clinical and psychosocial parameters between patients with a different severity of AD and to analyse the effect of an omega-6-fatty-acid-skin therapy.

Percutaneous drug delivery systems are attractive not only as a therapeutic strategy but also for cosmetic treatment. Iontophoresis is a well-recognized method for promoting transdermal absorption of ionized compounds. Franz cells are generally used to estimate drug permeation of skin by iontophoresis. However, methods using Franz cells are less versatile; for instance, the method is unsuited for use with a portable electric facial care device having a working probe of a certain size and weight. In this study, we constructed a semi-dry apparatus for use with an electric facial care device.

Eczema is a debilitating skin disorder clinically characterised by the development of itchy, dry, rough, and scaling skin caused by a series of rudimentary clinical phenotypes.

The skin, particularly the epidermis, is subjected to various external stresses, including ultraviolet (UV) irradiation. UV irradiation, mainly UVB at wavelength of 280-315 nm, can alter several epidermal functions, including cutaneous inflammation, epidermal hyperproliferation, DNA damage, disruption of epidermal permeability barrier and reduction in stratum corneum hydration levels. Because of the negative impacts of UVB irradiation on epidermal functions, great efforts have been made to develop regimens for the protection of alterations in epidermal function induced by UV irradiation.

Curcumin is a polyphenolic compound present in turmeric (Curcuma longa). Curcumin, turmeric powder, and extracts are widely used in traditional Indian medicine and are active ingredients of dietary supplements and cosmeceutical products. The pharmacological properties of curcumin/turmeric as well as the studies performed in vitro, in animal models, and in volunteers have been the objects of a vast literature. Most of the clinical studies report on the effects of curcumin/turmeric administered orally, while only a few describe its topical applications.

Folliculitis is a painful infection and inflammation of the hair follicles, mostly caused by bacterial, fungal, or, more rarely, viral infections. Turpentine derivatives have been used traditionally to treat various skin infections and could thus also be effective in treating folliculitis. We carried out an open, prospective, randomized, placebo- and comparator-controlled multicenter trial to evaluate the efficacy and safety of an ointment containing pine turpentine oil, larch turpentine, and eucalyptus oil in the treatment of acute folliculitis.

Diesel particulate matter (DPM) emitted from diesel engines is a major source of air pollutants. DPM is composed of elemental carbon, which adsorbs organic compounds including toxic polycyclic aromatic hydrocarbons (PAHs). The skin, as well as airways, is directly exposed to DPM, and association of atopic dermatitis, psoriasis flares, and premature skin aging with air pollutant levels has been documented. In skin, the permeation of DPM and DPM-adsorbed compounds is primarily blocked by the epidermal permeability barrier deployed in the stratum corneum. Depending upon the integrity of this barrier, certain amounts of DPM and DPM-adsorbed compounds can permeate into the skin. However, this permeation into human skin has not been completely elucidated.

Increased skin pH values in patients with atopic dermatitis (AD) contribute to poor antimicrobial and permeability barrier functions of the skin. In practice, the majority of topical preparations available for dry skin conditions do not provide sufficient pH and buffering capacity for maintaining optimum skin surface conditions. To address this issue, we tested a novel zinc lactobionate preparation to determine whether the regular application would lower skin surface pH, and in doing so improve the condition of lesional skin.

Compared to adults, newborns' skin has a thinner epidermis and stratum corneum with decreased hydration levels, higher transepidermal water loss, and a pH variation between 5.5 and 7.5. These characteristics can predispose to the occurrence of dryness, infections, and dermatological conditions. Water and liquid soap with adequate formulation have shown to be beneficial and safe for newborns' skin. However, studies evaluating the effect of bar soap, products widely used in Brazil and Latin America, are unknown. Therefore, the objective of this study was to compare the effects of liquid and bar soaps on the term newborns' skin.

Non-invasive measurement of the stratum corneum hydration (SCH) with capacitance-based instrumentation is established in dermatological and cosmetic studies. We wanted to test the reliability of non-invasive self-measurements for SCH performed under real-life conditions by volunteers with a Bluetooth-based (wireless) probe Corneometer® (CM 825i) transmitting the data via a smartphone application to a central server. Probes and smartphones communicated using Bluetooth Low Energy. Data from the smartphone were securely transferred to a remote server in a different country with TLS encryption using HTTPS protocols. CM 825i values were correlated with the established CM 825 under laboratory conditions. The primary endpoint was the correlation of the two probes. Secondary endpoints were the coefficient of variation (CV) and delta values (before and after treatment).

Linoleate-containing acylglucosylceramide (GLC-CER[EOx], where x = sphingosine [S], dihydrosphingosine [dS], phytosphingosine (P), or 6-hydroxysphingosine [H]) in the viable epidermis serve as the precursors to the linoleate-containing acylceramides (CER[EOx]) in the stratum corneum (SC) and the corneocyte lipid envelope (CLE), both of which are essential for the barrier function of the skin.

Disinfectants play a critical role in reducing healthcare-associated infections by eliminating microorganisms on surfaces. However, prolonged use of disinfectants may adversely affect the skin microflora, essential for skin health and infection prevention. This study investigates the impact of disinfection on the skin microbiota and metabolites of medical personnel in operating rooms, aiming to provide a scientific foundation for safeguarding their skin health.