Preparation and characterization of herbal creams for improvement of skin viscoelastic properties

The aim of this study was to formulate and evaluate herbal cosmetic creams for their improvement of skin viscoelastic and hydration properties. The cosmetic cream formulations were designed by using ethanolic extracts of Glycyrriza glabra, Curcuma longa (roots), seeds of Psorolea corlifolia, Cassia tora, Areca catechu, Punica granatum, fruits of Embelica officinale, leaves of Centella asiatica, dried bark of Cinnamon zeylanicum and fresh gel of Aloe vera in varied concentrations (0.12-0.9%w/w) and characterized using physicochemical and physiological measurements. The ethanolic extracts of herbs were incorporated in a cream base that is prepared by a phase inversion emulsification technique. The cream base was prepared by utilizing oil of Prunus amagdalus, Sesamum indicum, honey, cetyl alcohol, stearic acid, polysorbate monoleate, sorbitan monostearate, propylene glycol and glycerin. Physicochemical assessments and microbiological testing were completed for all formulations according to the methods of the Indian Standard Bureau. The studies were carried out for 6 weeks on normal subjects (6 males and 12 females, between 22 and 50 years) on the back of their volar forearm for evaluation of viscoelastic properties in terms of extensibility via a suction measurement, firmness using laboratory fabricated instruments such as ball bouncing and skin hydration using electric (resistance) measurement methods. The physicochemical parameters of formulations CAA1-CAA6, i.e. pH, acid value, saponification value, viscosity, spreadability, layer thickness microbial count and skin sensitivity were found to be in the range of 5.01 +/- 0.4-6.07 +/- 0.6, 3.3-5.1 +/- 0.2, 20-32, 5900-6755 cps, 60-99%, 25-50 mum, 31-46 colony-forming units (CFU) and a 0-1 erythema score. The formulations, CAA4 and CAA5, showed an increase in percentage extensibility (32.27 +/- 1.7% and 29.89 +/- 1.64%, respectively), firmness (28.86 +/- 0.86% and 29.89 +/- 2.8%, respectively) and improved skin hydration (15.97 +/- 0.55 and 18.27 +/- 0.99%, respectively) and were found more effective compared with the control product (C7) after the 6- week study.     

Short communication: Teat skin pH

Changes in teat skin surface pH were studied over 12 wk in 99 lactating Holstein cows. Half the udder of each cow routinely received postmilking disinfection, and the other half served as control. Measures of pH were made on all teats at weekly intervals. Teat skin pH was affected by treatment but not week. Mean teat skin pH measures were: 7.18 (+/- 0.64) and 7.53 (+/- 0.46) for treatment and control teats. In study II, pH teat skin measures were made hourly on 16 cows, starting 2 h before milking, immediately before a milking, immediately after a milking, and for 2 h postmilking. Teat skin pH was significantly lower for treatment teats and was lower for all teats postmilking.     

Experimental measurement of proton, Cd, Pb, Sr, and Zn adsorption onto the fungal species Saccharomyces cerevisiae

Proton, Cd, Pb, Sr, and Zn adsorption onto the fungal species Saccharomyces cerevisiae were measured in bulk adsorption experiments as a function of time, pH, surface: metal ratio, and ionic strength, and we measured the electrophoretic mobility of the cells as a function of pH. We modeled the acid/base properties of the fungal cell wall by invoking a nonelectrostatic surface complexation model with four discrete surface organic acid functional group types, with average pKa values (with 1 sigma uncertainties) of 3.4 +/- 0.4, 5.0 +/- 0.2, 6.8 +/- 0.4, and 8.9 +/- 0.6. The affinity of the fungal cells for the metal ions follows the following trend: Pb > Zn > Cd > Sr. We used the metal adsorption data to determine site-specific stability constants for the important metal fungal surface complexes. Our results suggest that S. cerevisiae may represent a novel biosorbent for the removal of heavy metal cations from aqueous waste streams.     

The effect of smoking on skin moisture and on surface lipids

In the present retrospective study we investigated the effect of smoking on the moisture and surface lipid levels of the skin. We analysed data from the files of 576 female clients treated in a Tel-Aviv cosmetic parlour. Measurements have been conducted by the same cosmetician, by commercially available equipment, on every client receiving cosmetic treatment, regardless of the nature of the treatment.
Results demonstrated a significant difference of skin moisture in the various smoking groups: women who smoked 11–20 cigarettes per day showed significantly lower mean values than the non-smoker group, as expected. Moreover, women before or after menopause showed no significant differences in their moisture measurements.
The surface lipid variables showed no significant differences in mean over the four smoking groups.
We believe that the objective of the study was achieved, and that the results, indicating decreased skin moisture in smokers, will serve well in anti-smoking campaigns. We also believe that the present study will stimulate other investigators to conduct similar studies that will provide answers to the many questions which still remain open.     

Lipoprotein creams: utilization of multifunctional ingredients for the preparation of cosmetic emulsions with excellent skin compatibility

Lipoproteins are plant-derived surface-active biopolymers, which act as emulsifying as well as viscosity-enhancing agents in oil-in-water emulsions. Depending on the degree of hydrolization, lipoproteins are dispersible or even soluble in water. In the presence of low to medium polar oils, lipoproteins are adsorbed and align at the oil-water interface, whereas in mixtures with high polar oils the lipoproteins are repelled from the oil-water interface. The water-dispersible lipoproteins show higher interfacial activity than the hydrolysates. Lipoproteins bear a negative electric charge in aqueous dispersions at pH 6.5, which is probably the reason for the stabilization of oil droplets against coalescence. Lipoprotein creams were characterized in terms of particle size, rheology, and emulsion stability against sedimentation, which was evaluated by a near-infrared sedimentometer. After topical application, emulsion stability breaks down and an emulsion film is formed on the skin surface. Lipoprotein creams cause a distinct increase in skin pliability and skin moisture and show excellent skin compatibility. In a home use test the panelists appreciated the cosmetic and caring properties of the lipoprotein cream.     

La microscopie confocale: interet pour l'analyse du relief cutané. Un outil d'évaluation dermo-cosmétique

Nowadays, the determination of human skin microtopography is usually carried out by methods based on mechanical techniques (profilometry and surfometry), or founded on optical conception (shadowing method and profilometry). Negative skin replicas made of a silicone rubber material (Silflo((R))) or positive casts performed from an epoxy resin (Araldite((R))), are used to assess the skin microstructure. Skin surface microtopography is quantified by measuring furrows depths and spaces between them. An original application using confocal scanning laser microscope (CLSM) is described in this paper. The CLSM gives simultaneously images of the skin surface associated with quantitative measurements of the microtopography. With this apparatus, it is easy to achieve perfect skin replica images with assessment of its microstructure, before and after applications of topical medicines or cosmetic products to evaluate the skin surface restoration. It is worth to mention that it is indispensable to analyse the same skin surface (same plateaux and same furrows). For this reason, it is necessary to localize exactly and to replicate the same skin surface area (4 mm(2)) before and after the cosmetic use, whatever the extended period of the topical application.     

The performance of a medico-cosmetic consultation unit

The facial skin of almost 500 women was measured by low pressure indentometry and surface pH-metry. The women's skin was also classified by visual observation by a well-trained cosmetician. Agreement between indentometry and cosmetic definition was found to be well correlated, except in the group of young women with dry skin. In this group, we believe, indentometry more accurately describes skin status. A significant relationship was found between high skin pH (>5.9) and lack of elasticity in the older age group with dry skin. It is hypothesized that high skin surface pH below the age of 70 is an expression of accelerated ageing process, and further, that chronic, high pH treatment of the skin leads to accelerated loss of skin elasticity. L'évaluation objective de l'état cosmétique de la peau en milieu medical La peau du visage de près de 500 femmes a été examinée par indentométrie, basse pression et par pH métrie superficielle. Les types de peau ont également été classés visuellement par un cosméticien entraîne. On a trouvé une bonne corrélation entre la définition cosmétique et les résultats de l'indentométrie sauf pour un groupe composé de jeunes femmes à peau sèche. Nous pensons que pour ce groupe ce sont les résultats de l'indentométrie qui permettent la meilleure appréciation de l'état de la peau. Dans un groupe de personnes plus âgées à peau sèche on a trouvé une relation significative entre des valeurs élevées du pH de la peau (pH > 5.9) et son manque d'élasticité. On a émis l'hypothèse que des valeurs élevées du pH cutané chez des sujets de moins de 70 ans constituaient une manifestation de vieillissement précoce et par tant que le traitement régulier avec les produits de pH élevé pouvait conduire à une perte d'elasticité plus rapide de la peau.     

The alkaline pH-adapted skin barrier is disrupted severely by SLS-induced irritation

The pH of the healthy skin is 5.5 and maintained by many regulatory mechanisms. The pH of the skin care product we use on a daily basis can have an influence on the skin properties. To investigate how the physical properties of skin change after the alkaline or acidic pH of the skin care products are applied on the skin for a long term, we adjusted the pH of the skin care products to 3, 5 and 8 (A, B, C), with glycolic acid and triethanolamine. For 5 weeks the skin care products were applied on 20 healthy subjects' ventral forearm and the skin physical properties were measured. After 5 weeks, skin responses to the external stress of 1% (w/v) SLS (sodium lauryl sulphate) irritation and erythema by UV were measured. Skin colour and skin UV response were not altered by the pH. However, on the C-applied site (pH 8) the transepidermal water loss of stratum corneum (SC) increased significantly, the water content increased and desquamation decreased, respectively, and the SLS significantly impaired the skin barrier in comparison with other sites. The alkaline skin care product impaired the skin barrier after repeated application over 5-week period and the skin barrier was disrupted severely by 1% SLS exposure because SC was already impaired by alkaline pH and sensitive to external stress. This suggests that the pH of daily skin care products is very important for skin barrier homeostasis.     

Influence of skin cleansing preparation acidity on skin surface properties

Two long-term trials were conducted each over eight weeks to compare the effect of the regular application of skin cleansing preparations of pH 5.5 and pH 8.5 and pH 5.5 and pH 7.0 respectively on the surface pH, roughness and transepidermal water loss (TEWL) of normal human forehead and forearm skin. Both trials were based on a cross-over design: five healthy volunteers started with a pH 5.5 preparation and switched to the other after four weeks, five additional volunteers used the preparations in the opposite order. While the skin surface pH was markedly lower in those individuals using the pH 5.5 preparation at each examination, as compared to those using the pH 8.5 or pH 7.0 preparation, no such difference could be established with respect to skin roughness and TEWL. Hence the skin irritancy of a cleansing preparation does not seem to be linked to its pH within the pH ranges tested.     

Magnitude and directional measures of water and Cr(VI) fluxes by passive flux meter

A new configuration of the passive fluxmeter (PFM) is presented that provides for simultaneous measurements of both the magnitude and the direction of ambient groundwater specific discharge qo and Cr(VI) mass flux J(Cr). The PFM is configured as a cylindrical unit with an interior divided into a center section and three outer sectors, each packed with a granular anion exchange resin having high sorption capacity for the Cr(VI) oxyanions CrO4(2-) and HCrO4-. The sorbent in the center section is preloaded with benzoate as the "resident" tracer. Laboratory experiments were conducted in which PFMs were placed in porous packed bed columns, through which was passed a measured volume of synthetic groundwater containing Cr(VI). During the deployment period, some of the resident tracer is depleted while the Cr(VI) is sorbed. The resin was then removed from the four sectors separately and extracted to determine the "captured" mass of Cr(VI) and the residual mass of the resident tracer in each. Cumulative specific discharge, q0t, values were assessed using the residual mass of benzoate retained in the center section. The direction of this discharge theta was ascertained from the mass distribution of benzoate intercepted and retained in the outer three sections of the PFM. Cumulative chromium fluxes, J(Cr)t, were quantified using the total Cr(VI) mass intercepted and retained on the PFM. Experiments produced an average measurement error for direction theta of 3 degrees +/- 14 degrees, while the average measurement errors for q0 and J(Cr) were, respectively, -8% +/- 15% and -12% +/- 23%. Results demonstrate the potential utility of the new PFM configuration for characterizing groundwater and contaminant fluxes.     

Sex- and site-dependent variations in the thickness and mechanical properties of human skin in vivo

A new method for the in vivo characterization of the physical properties of skin is presented. This comprises an ultrasound device to measure the vertical displacement of the surface of the skin, as well as its thickness and that of the hypodermis under suction. In combination with this, a mathematical model is used to calculate the following skin parameters: Young's modulus, the initial stress and an index of non-elasticity. These parameters were evaluated from the volar forearm and the forehead of 30 male and 30 females, of similar ages (28 +/- 6-years-old). The sensitivity of the testing procedure, allowing the characterization of the mechanical parameters of the skin, easily differentiated these two sites, and in some cases, differences between women and men were demonstrated. The main results showed for both sexes that the thickness (P = 0.0001), Young's modulus (P = 0.0001), and the index of non-elasticity (P = 0.0001) were greater for the forehead than for the ventral forearm, but that the initial stress was lower (P = 0.0001). The results show that the skin is thicker, stiffer and less tense and elastic on the forehead than on the ventral forearm, suggesting structural differences between these two sites (collagen fibre network, elastic fibres, epidermis, stratum corneum, microvascularization, actinic damage, presence of sebaceous glands, etc.). It is hoped that this device will be useful for the evaluation of certain skin disorders (scleroderma, Ehlers-Danlos syndrome, cutis laxa, oedema, etc.) and their therapy, as well as being a useful tool in skin ageing and cosmetic product assessment.     

Headspace analysis study of evaporation rate of perfume ingredients applied onto skin

Diffusion of perfume ingredients from skin or hair is measured using an original method based on dynamic headspace technology. This has been used for pure odorants, fine fragrances, as well as for perfumed cosmetic applications such as soaps, creams or shampoos, in order to characterize diffusion processes and air/skin or air/hair partitioning. Accordingly, a special collection system, applied on the inner face of the forearm, has been developed, allowing the adsorption of diffusing organic vapours from skin onto Tenax (poly-diphenyl phenylene oxide) with a controlled air flow rate. A simple model composition containing eleven volatile synthetic odorants was prepared in an alcoholic matrix and the solution was applied onto the skin. The diffusion rate of the different components was measured by determining the concentration of each in the gas phase versus time. Conversely, the same experiment was effected by the application of an alcoholic solution of each individual component. In this manner, the relative diffusion from skin of the components alone or mixed was compared using the same experimental technique. The effect of a musky component was also tested. Both compositions (with and without musk) were then applied in a soap base. Thus, following a rigorous protocol, the forearm was washed with the perfumed soap and rinsed with water before collection of the headspace. The results show the different diffusion rates of the individual odorants. In particular, components evaporate slower from the skin when they have been applied from a soap bar compared to when they have been applied from alcoholic solution. We also present results describing the characterization of skin types using a panel comprised of 80 people (40 females and 40 males); amount of sebum, hydration and pH were systematically measured on different parts of the face, the neck as well as the outer and inner faces of the forearm. The panelists were then classified into different sub-groups taking into account these parameters. It should be noted that the foregoing results were obtained on an ‘average’skin type.     

Kinetics of nitrate, nitrite, and Cr(VI) reduction by iron metal

The kinetics of nitrate, nitrite, and Cr(VI) reduction by three types of iron metal (Fe0) were studied in batch reactors for a range of Fe0 surface area concentrations and solution pH values (5.5-9.0). At pH 7.0, there was only a modest difference (2-4x) in first-order rate coefficients (k(obs)) for each contaminant among the three Fe0 types investigated (Fisher, Peerless, and Connelly). The k(obs) values at pH 7.0 for both nitrite and Cr(VI) reduction were first-order with respect to Fe0 surface area concentration, and average surface area normalized rate coefficients (kSA) of 9.0 x 10(-3) and 2.2 x 10(-1) L m(-2) h(-1) were determined for nitrite and Cr(VI), respectively. Unlike nitrite and Cr(VI), Fe0 surface area concentration had little effect on rates of nitrate reduction (with the exception of Connelly Fe0, which reduced nitrate at slower rates at higher Fe0 surface areas). The rates of nitrate, nitrite, and Cr(VI) reduction by Fisher Fe0 decreased with increasing pH with apparent reaction orders of 0.49 +/- 0.04 for nitrate, 0.61 +/- 0.02 for nitrite, and 0.72 +/- 0.07 for Cr(VI). Buffer type had minimal effects on reduction rates, indicating that pH was primarily responsible for the differences in rate. At high pH values, Cr(VI) reduction ceased after a short time period, and negligible nitrite reduction was observed over 48 h.     

Effect of pH and aging time on the kinetic dissociation of 243Am(III) from humic acid-coated gamma-Al2O3: a chelating resin exchange study

The chelating resin was studied to assess its influence on metal availability and mobility in the environment. The association of organic-inorganic colloid-borne trace elements was investigated in this work. The radionuclide 243Am(III) was chosen as the representative and chemical homologue for trivalent lanthanide and actinide ions present in radioactive nuclear waste. The kinetic dissociation behavior of 243Am(III) from humic acid-coated gamma-Al2O3 was studied at pH values of 4.0 +/- 0.1, 5.0 +/- 0.2, and 6.0 +/- 0.2 with a contact time of 2 days after the addition of a chelating cation exchanger resin. The concentrations of the components were: 243Am(III) 3.0 x 10(-7) mol/L, gamma-Al2O3 0.5 g/L, HA 10 mg/L (pH 4.0 +/- 0.1, 5.0 +/- 0.2, and 6.0 +/- 0.2) and 50 mg/L (pH 6.0 +/- 0.2), respectively. The kinetics of dissociation of 243Am(III) after different equilibration time with humic acid-coated gamma-Al2O3 was also investigated at pH 5.0 +/- 0.2. The experiments were carried out in air and at ambient temperature. The results suggest that the fraction of irreversible bonding of radionuclides to HA-coated Al2O3 increases with increasing pH and is independent of aging time. The assumption of two different 243Am(III)-HA-Al2O3 species, with "fast" and "slow" dissociation kinetics, is required to explain the experimental results. 243Am(III) species present on HA-Al2O3 colloids moves from the "fast" to the "slow" dissociating sites with the increase of aging time.     

Oral fish cartilage polysaccharides in the treatment of photoageing: biophysical findings

The topically applied cosmetic products can be helpful in improving the aged skin condition. The present study shows how oral fish-cartilage food supplementation can be helpful in improving the treatment of ageing skin. A total of 30 healthy women with signs of skin ageing were studied. Fifteen of the women were treated with a food supplement based on polysaccharides derived from the fish cartilage and a natural mix of antioxidants for 2 months and the other 15 with a placebo. Clinical evaluation and biophysical parameters related to skin function and wrinkle severity, such as silicone replica, skin thickness, mechanical properties, skin colour and capacitance, were measured. The results showed statistically significant changes in the active-treated group in comparison to the placebo. In particular, dermal thickness (treatment: from 1.13 to 1.23 mm; P < 0.001), skin wrinkling (treatment: from 9.5 to 3.5 R(a); P< 0.002), skin colour (treatment: brighter and less pigmented; P < 0.02) and viscoelasticity (treatment: from 0.70 to 0.97%; P < 0.02) showed considerable improvement. Most of these parameters are related to changes occurring within the dermal matrix, which is improved after the treatment, whereas most of the topically applied cosmetic products have a short-term effect on superficial structures. A combination treatment (oral and topical) can be more effective in reducing the signs of skin-ageing.     

Global classification of human facial healthy skin using PLS discriminant analysis and clustering analysis

Today's classifications of healthy skin are predominantly based on a very limited number of skin characteristics, such as skin oiliness or susceptibility to sun exposure. The aim of the present analysis was to set up a global classification of healthy facial skin, using mathematical models. This classification is based on clinical, biophysical skin characteristics and self-reported information related to the skin, as well as the results of a theoretical skin classification assessed separately for the frontal and the malar zones of the face. In order to maximize the predictive power of the models with a minimum of variables, the Partial Least Square (PLS) discriminant analysis method was used. The resulting PLS components were subjected to clustering analyses to identify the plausible number of clusters and to group the individuals according to their proximities. Using this approach, four PLS components could be constructed and six clusters were found relevant. So, from the 36 hypothetical combinations of the theoretical skin types classification, we tended to a strengthened six classes proposal. Our data suggest that the association of the PLS discriminant analysis and the clustering methods leads to a valid and simple way to classify healthy human skin and represents a potentially useful tool for cosmetic and dermatological research.     

Effect of various chemical decontamination treatments on natural microflora and sensory characteristics of poultry

Regulation (EC) No. 853/2004 of the European Parliament and of the Council provides a legal basis permitting the use of antimicrobial treatments to remove surface contamination from poultry. This paper reports the results of research into the effects on natural microflora, pH, and sensorial characteristics achieved by dipping chicken legs (15 min, 18+/-1 degrees C) into solutions (wt/vol) of 12% trisodium phosphate (TSP), 1200 ppm acidified sodium chlorite (ASC), 2% citric acid (CA), 220 ppm peroxyacids (Inspexx 100; PA), and water. Samples were collected immediately after evisceration, subjected to the treatments listed or left untreated (control) and tested after 0, 1, 3 and 5 days of storage (3 degrees C+/-1 degrees C). For most microbial groups similar counts were observed on water-dipped and on untreated legs. All the chemical compounds were effective in reducing microbial populations throughout storage, with TSP, ASC and CA showing the strongest antimicrobial activity. The average reductions (mean+/-standard deviation) relative to untreated samples caused by chemical treatments when considering simultaneously all storage days ranged (log(10) cfu/g skin) from 0.53+/-0.83 (PA) to 1.98+/-0.62 (TSP) for mesophilic aerobic counts, from 0.11+/-0.89 (PA) to 1.27+/-1.02 (CA) (psychrotrophs), from 1.34+/-1.40 (PA) to 2.15+/-1.20 (CA) (Enterobacteriaceae), from 1.18+/-1.24 (PA) to 1.98+/-1.16 (CA) (coliforms), from 0.66+/-0.99 (PA) to 1.86+/-1.80 (TSP) (Micrococcaceae), from 0.54+/-0.74 (TSP) to 2.17+/-1.37 (CA) (enterococci), from 0.72+/-0.66 (TSP) to 2.08+/-1.60 (CA) (Brochothrix thermosphacta), from 0.78+/-1.02 (PA) to 1.99+/-0.96 (TSP) (pseudomonads), from 0.21+/-0.61 (PA) to 1.23+/-0.60 (TSP) (lactic acid bacteria), and from 1.14+/-0.89 (PA) to 1.45+/-0.61 (ASC) (moulds and yeasts). The microbial reductions throughout storage increased, decreased, or did not vary, in accordance with microbial group and chemical involved. Similar pH values were observed for untreated samples and for those dipped in PA and water on all sampling days. ASC-treated samples showed a lower pH than controls to day 1. TSP-treated legs exhibited the highest pH values and CA-treated ones the lowest, throughout storage. Hedonic evaluation (nine-point structured scale, untrained panellists) showed similar colour, smell and overall acceptability scores for dipped and untreated samples on day 0 and day 1. From day 3 sensorial attributes scored lower for untreated, PA- and water-dipped legs, as compared to legs treated with TSP, ASC and CA. Only for these three groups of samples were average scores higher than 6 (shelf-life limit value) observed by the end of storage. Results from the present study suggest that the treatments tested improve the microbial quality of chicken without adverse sensorial effects.     

Multicenter study on measurement of the natural pH of the skin surface

Characterization of the skin's natural state is very important for understanding skin functions and describing disturbances of skin function. In the field of cosmetics and dermatologicals the natural pH of the skin surface plays an important role in the development of products with a skin neutral pH. In a multicenter study the natural pH of the skin surface (exception of underarm and genital areas), was to be measured. It was to be determined whether gender-specific differences in the pH occur. The skin surface pH was measured on the inside of the forearms in 222 volunteers (147 female, 75 male) using the skin pH meters of the respective institutes. The pH was measured in triplicate on adjacent areas 24 h after the last contact of the measuring site with water, topical applications and an intensive washing procedure. The values of the skin surface pH were 4.9 (arithmetic mean). The 95% interval was between 4.1 and 5.8. The pH on the forearm of the male volunteers was slightly lower than that of the females. The difference was statistically significant (p < 0.01; 4.8 to 5.0). The authors suggest that the GDCh recommendations for the claims >>skin neutral pH«, >>ideal pH« or >>skin-friendly pH« should be revised and propose a pH range of 4.1 to 5.8 for the main body areas excluding the underarm and genital areas.     

Effect of fluid intake on skin physiology: distinct differences between drinking mineral water and tap water

It is generally stated that drinking plenty of water has a positive influence on skin condition. However, there is no published scientific study that has investigated this matter. The aim of our exploratory 'before-after' study was to evaluate the in vivo influence of drinking more than 2 L of mineral water or ordinary tap water per day on skin physiology. Ninety-three healthy subjects were included in our prospective study. After an initial run-in phase of 2 weeks to monitor individual drinking habits, subjects had to drink 2.25 L day(-1) of either mineral water (n = 53) or tap water (n = 40) for 4 weeks. Bioengineering in vivo measurements on the volar forearm included sonographic evaluation of skin thickness and density, determination of skin surface pH, assessment of skin surface morphology, and measurement of finger circumference. Eighty-six subjects completed the study. In the mineral water group measurements revealed a statistically significant decrease in skin density. Skin thickness increased slightly, albeit not at a statistically significant level. However, when separately analysing those individuals from the mineral water group, who had routinely drunken comparably little before the start of the study, their skin thickness increased at a statistically significant level. Skin surface pH remained almost unchanged in the physiologically optimal range. In the tap water group, skin density increased significantly, while skin thickness decreased significantly. Skin surface pH decreased at a statistically significant level. While in the mineral water group finger circumference decreased significantly, measurements in the tap water group revealed a statistically significant increase. Objective skin surface morphology did not change in any group. In summary, drinking more than 2 L of water per day can have a significant impact on skin physiology. The exact effects within the skin seem to differ depending on the nature of the water ingested. Randomized, controlled, double-blind follow-up trials are warranted to confirm the findings of our exploratory pilot study.