Effects of 1,3-propanediol associated, or not, with butylene glycol and/or glycerol on skin hydration and skin barrier function.

OBJECTIVE: This study aimed to assess the effect of 1,3-propanediol at different concentrations (5%, 10%, or 15%), either applied alone or in combination with butylene glycol (BG) (5%) and/or glycerol (5%), on skin hydration and skin barrier function. The measurements were conducted using capacitance to determine skin hydration and trans epidermal water loss (TEWL) rates to evaluate skin barrier function. METHODS: A total of 30 healthy female subjects participated in the study. Capacitance and TEWL measurements were conducted at multiple time points, including before application and at 15 min, 2 and 8 h after the humectants were applied to the forearms of the subjects. All the subjects provided written informed consent. RESULTS: The 1,3-propanediol in all concentrations and in all combinations (with BG and/or glycerol) increased skin hydration and improved skin barrier function 15 min, 2 and 8 h after application. Glycerol increased the hydration performance of 1,3-propanediol. The application of 1,3-propanediol at a concentration of 15%, either alone or in combination with other humectants, reduced the TEWL to a greater extent than lower concentrations of 1,3-propanediol. Furthermore, the addition of glycerol to 1,3-propanediol 15% improved the skin barrier and reduced TEWL when compared with 1,3-propanediol alone and with the combination of 1,3-propanediol + BG. CONCLUSION: The humectants significantly improved skin hydration and reduced TEWL throughout the 8-h time course. The increase in 1,3-propanediol concentration, as well as its combination with glycerol, provided a greater benefit to the skin, improving both hydration and the skin barrier function.

OBJECTIF: Cette étude visait à évaluer l'effet sur l'hydratation de la peau et la fonction de barrière cutanée du 1,3-propanediol à différentes concentrations (5 %, 10 % ou 15 %), appliqué seul ou en association avec du butylène glycol (5 %) et/ou du glycérol (5 %). Les mesures ont été effectuées à l'aide de la capacitance pour déterminer l'hydratation de la peau et les taux de perte d'eau transépidermique (Trans Epidermal Water Loss, TEWL) pour évaluer la fonction de barrière cutanée. MÉTHODES: Au total, 30 sujets de sexe féminin en bonne santé ont participé à l'étude. Les mesures de la capacitance et de la TEWL ont été effectuées à plusieurs moments, y compris avant l'application, 15 minutes, 2 heures et 8 heures après l'application des produits humectant sur les avant-bras des sujets. Tous les sujets ont fourni un consentement éclairé écrit. RÉSULTATS: Le 1,3-propanediol, à toutes les concentrations et dans toutes les associations (avec le butylène glycol et/ou le glycérol), a augmenté l'hydratation de la peau et amélioré la fonction de barrière cutanée à 15 minutes, 2 heures et 8 heures après l'application. Le glycérol a augmenté les performances d'hydratation du 1,3-propanediol. L'application de 1,3-propanediol à une concentration de 15 %, seul ou en association avec d'autres produits humectant, a réduit la TEWL dans une plus grande mesure que des concentrations inférieures de 1,3-propanediol. En outre, l'ajout de glycérol au 1,3-propanediol 15 % a amélioré la barrière cutanée et réduit la TEWL par rapport au 1,3-propanediol seul et à l'association 1,3-propanediol + butylène glycol. CONCLUSION: Les produits humectant ont significativement amélioré l'hydratation de la peau et réduit la TEWL tout au long des 8 heures. L'augmentation de la concentration de 1,3-propanediol, ainsi que son association avec le glycérol, ont apporté un plus grand bénéfice à la peau, améliorant à la fois l'hydratation et la fonction de barrière cutanée.

Preparation of Microemulsion from an Alkyl Polyglycoside Surfactant and Tea Tree Oil.

Preparation and characterization of microemulsions consisting of a plant-derived alkyl polyglycoside (APG) surfactant and the essential oil of Melaleuca alternifolia (tea tree) was studied. This nonionic APG surfactant used was Triton CG-110 with a CMC at 1748 ppm at 25 °C. Tea tree oil (TTO) was extracted from tea tree leaves by Triton CG-110-assisted hydrodistillation method. The preparation of the microemulsion was aided by the construction of pseudo-ternary phase diagrams, which were investigated at the different weight ratios of surfactant mixtures (Smix = Triton CG-110/PPG) as 0.6:1, 1.8:1, 1:0 with hydrodistilled and commercial TTO by water titration method at room temperature. Particularly, structure of microemulsion was identified by electrical conductivity and viscosity. Moreover, shelf stability of some microemulsion made of 1% TTO with various concentration of Triton CG-110/PPG (1.8:1 w/w) were monitored for over a two-month period with dynamic light scattering. These results showed that microemulsion made of 1% TTO, 9% Triton CG-110/PPG (1.8:1 w/w) was insensitive with time and temperature of storage.

Moisturizing mechanism of glycerol and diglycerol on human stratum corneum studied by synchrotron X-ray diffraction.

OBJECTIVE: Polyols are moisturizers used in cosmetics. Using X-ray diffraction, we studied the moisturizingmechanism of polyol solutions in the stratum corneum (SC). We examined whether glycerol disrupts the ordered hydrocarbon chain packing structure in isolated SC, as previously proposed in an SC lipid model. METHODS: The SC samples were prepared by treatment with water and aqueous solutions of glycerol, diglycerol and glycerol/diglycerol. To examine the differences in the water-retention efficiency of polyols, using a solution cell, we performed dynamic X-ray diffraction to analyse the structural changes that occurred during water removal from the hydrated samples by a stream of dry nitrogen gas. We focused on two structures, the orthorhombic hydrocarbon chain packing structure in the intercellular lipids and the soft keratin in the corneocytes where most of the water is stored. RESULTS: The spacing formed by the soft keratin in the corneocytes immersed in a solution of water and diglycerol solution decreased rapidly by water removal. In contrast, it decreased gradually in the corneocytes immersed in a solution of glycerol and glycerol/diglycerol, indicating that the glycerol-containing solutions maintained the hydrated state of the corneocytes for longer. Furthermore, the characteristic change of the spacing in the orthorhombic hydrocarbon chain packing structure over time was observed during the drying process. The hydrated state was maintained longer, in water, followed by glycerol, diglycerol and glycerol/diglycerol, in increasing order. This is the first study to report such characteristic properties that could be indicators of the capacity of the SC to regulate water. CONCLUSION: The dynamic X-ray diffraction experiment on the structure of the soft keratin and the orthorhombic hydrocarbon chain packing structure during the drying of the hydrated SC provides an insight into the moisturizing mechanism of the polyol solutions in the SC. The results show that the glycerol/diglycerol solution functions as an effective SC moisturizer at the molecular level. Further, it was confirmed that the behaviour of glycerol in the isolated SC varies from that proposed in the SC lipid model, wherein glycerol was proposed to prevent the formation of a regular hydrocarbon chain packing structure.

OBJECTIF: les polyols sont des hydratants utilisés dans les cosmétiques. À l'aide de la diffractions des rayons X, nous avons étudié le mécanisme d'hydratation des solutions de polyols dans la couche cornée (stratum corneum, SC).Notre étude avait pour but de déterminer si le glycérol perturbe la structure d'empilement de la chaîne d'hydrocarbures ordonnée dans les SC isolés, comme proposé précédemment dans un modèle lipidique de SC. MÉTHODES: les échantillons de SC ont été préparés avec de l'eau et des solutions aqueuses de glycérol, de diglycérol et de glycérol/diglycérol. Pour examiner les différences d'efficacité de rétention d'eau des polyols à l'aide d'une cellule de solution, nous avons effectué une diffraction dynamique des rayons X pour analyser les changements structurels qui se sont produits pendant l'élimination de l'eau des échantillons hydratés par un flux d'azote sec. Nous avons mis l'accent sur deux structures, la structure d'empilement des chaînes d'hydrocarbures orthorhombiques dans les lipides intercellulaires et la kératine molle dans les cornéocytes où la majeure partie de l'eau est stockée. RÉSULTATS: l'espacement causé par la kératine molle dans les cornéocytes immergés dans une solution d'eau et de diglycérol a diminué rapidement en raison de l'élimination de l'eau. En revanche, il a diminué progressivement dans les cornéocytes immergés dans une solution de glycérol et de glycérol/diglycérol, ce qui indique que les solutions contenant du glycérol ont maintenu l'état hydraté des cornéocytes plus longtemps. De plus, la modification caractéristique de l'espacement dans la structure d'empilement de la chaîne d'hydrocarbures orthorhombique au fil du temps a été observée au cours du processus de séchage. L'état hydraté a été maintenu plus longtemps, dans l'eau, suivi par le glycérol, le diglycérol et le glycérol/diglycérol, dans un ordre croissant. C'est la première étude à faire état de telles propriétés caractéristiques qui pourraient être des indicateurs de la capacité du SC à réguler l'eau. CONCLUSION: l'expérience de diffraction dynamique des rayons X sur la structure de la kératine molle et la structure d'empilement de la chaîne d'hydrocarbures orthorhombique pendant le séchage du SC hydraté donne un aperçu du mécanisme hydratant des solutions de polyols dans le SC. Les résultats montrent que la solution de glycérol/diglycérol agit comme un hydratant de SC efficace au niveau moléculaire. De plus, il a été confirmé que le comportement du glycérol dans le SC isolé varie par rapport à celui proposé dans le modèle lipidique SC, où le glycérol a été proposé pour prévenir.

Effects of water gradients and use of urea on skin ultrastructure evaluated by confocal Raman microspectroscopy.

The rather thin outermost layer of the mammalian skin, stratum corneum (SC), is a complex biomembrane which separates the water rich inside of the body from the dry outside. The skin surface can be exposed to rather extreme variations in ambient conditions (e.g. water activity, temperature and pH), with potential effects on the barrier function. Increased understanding of how the barrier is affected by such changes is highly relevant for regulation of transdermal uptake of exogenous chemicals. In the present study we investigate the effect of hydration and the use of a well-known humectant, urea, on skin barrier ultrastructure by means of confocal Raman microspectroscopy. We also perform dynamic vapor sorption (DVS) microbalance measurements to examine the water uptake capacity of SC pretreated with urea. Based on novel Raman images, constructed from 2D spectral maps, we can distinguish large water inclusions within the skin membrane exceeding the size of fully hydrated corneocytes. We show that these inclusions contain water with spectral properties similar to that of bulk water. The results furthermore show that the ambient water activity has an important impact on the formation of these water inclusions as well as on the hydration profile across the membrane. Urea significantly increases the water uptake when present in skin, as compared to skin without urea, and it promotes formation of larger water inclusions in the tissue. The results confirm that urea can be used as a humectant to increase skin hydration.

The Toxicological Effects of e-Cigarette Use in the Upper Airway: A Scoping Review.

OBJECTIVE: While evidence continues to emerge on the negative health effects of electronic cigarettes (e-cigarettes) on the lungs, little is known regarding their deleterious effects on the upper airway. The purpose of this review is to summarize the toxicological effects of e-cigarettes, and their components, on the upper airway. DATA SOURCES: PubMed, SCOPUS, EMBASE databases. REVIEW METHODS: Systematic searches were performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines from 2003 to 2023. Studies were included if they investigated the toxicological effects of e-cigarette exposure on human or animal upper airway tissue. Two authors independently screened, reviewed, and appraised all included articles. RESULTS: A total of 822 unique articles were identified, of which 53 met inclusion criteria and spanned subsites including the oral cavity (22/53 studies), nasal cavity/nasopharynx (13/53), multiple sites (10/53), larynx (5/53), trachea (2/53), and oropharynx (1/53). The most commonly observed consequences of e-cigarette use on the upper airway included: proinflammatory (15/53 studies), histological (13/53), cytotoxicity (11/53), genotoxicity (11/53), and procarcinogenic (6/53). E-cigarette humectants independently induced toxicity at multiple upper airway subsites, however, effects were generally amplified when flavoring(s) and/or nicotine were added. Across almost all studies, exposure to cigarette smoke exhibited increased toxicity in the upper airway compared with exposure to e-cigarette vapor. CONCLUSION: Current data suggest that while e-cigarettes are generally less harmful than traditional cigarettes, they possess a distinct toxicological profile that is enhanced upon the addition of flavoring(s) and/or nicotine. Future investigations into underexamined subsites, such as the oropharynx and hypopharynx, are needed to comprehensively understand the effects of e-cigarettes on the upper airway.

Biological, surface, and wetting behavior of bio-surfactants tank-mixed with trifloxysulfuron-sodium on Sorghum halepense.

BACKGROUND: There is a public interest in developing bio-surfactants due to their low toxicity and high biodegradation potential. However, their biological, surface, and behavior to use with agrochemicals has not been investigated. RESULTS: Critical micelle concentrations (CMCs) for the synthetic surfactant dioctyl sodium sulfosuccinate (DOSS), the bio-surfactant rhamnolipid (RL), and the bio-surfactant surfactin (SF) were 1200, 50, and 50 mg L-1 , respectively. Based on the ability of the surfactants to reduce the surface tension of trifloxysulfuron-sodium spray solution at 0.25 to 1× CMC, they are ranked SF > RL > DOSS, while at 1.5 to 4× CMC, they are ranked SF = RL > DOSS. Without surfactant, trifloxysulfuron-sodium at 10.04 g ha-1 reduced johnsongrass growth up to 50% (ED50 ). At best, SF at 1 to 4× CMC halved ED50 . Unlike DOSS, which increased ED50 (12.89 g ha-1 ) due to a phytotoxic effect, SF and RL at 4× CMC decreased ED50 (5.19 and 6.50 g ha-1 , respectively) without a phytotoxic effect. A 5-µl droplet containing SF dried faster due to greater spread on the leaf surface than other surfactants. Although the wetted area of the leaf with the droplet containing RL was wider than that of DOSS, it took longer to dry. This observation contradicts the previous theory. CONCLUSION: In terms of dosage, safety, and efficacy, the RL and SF were comparable to DOSS in other tank-mix with trifloxysulfuron-sodium. It seems that RL also works as a humectant, while SF likely works as a wax solubilisant. © 2023 Society of Chemical Industry.

Efficacy Evaluation of a Topical Hyaluronic Acid Serum in Facial Photoaging.

INTRODUCTION: Hyaluronic acid (HA) acts as a biologic humectant, thus retaining water in the skin, making HA useful as a topical moisturizing ingredient. The goal of the research was to evaluate the ability of a HA facial serum to deliver skin benefits. METHODS: Forty females 30-65 years of age with Fitzpatrick skin types I-VI who exhibited photoaging used the HA facial serum twice daily with sunscreen. The dermatologist investigator evaluated smoothness, plumping, hydration, fine lines/wrinkles, and global appearance issues on a 5-point ordinal scale. The subjects assessed product tolerability in terms of stinging, itching, and burning. Corneometry was undertaken, with assessments performed at baseline, immediately after application, and at weeks 2, 4, and 6. Facial swabbing and photography were performed at the same intervals on a subset of 15 subjects. RESULTS: The HA serum demonstrated excellent tolerability and produced an increase in skin hydration (as measured by corneometry) immediately after application of 134% (p < 0.001), with a sustained increase of 55% (p < 0.001) at week 6. At week 6, there was also improvement (p ≤ 0.001) in all evaluated attributes: smoothness (64%), plumping (60%), hydration (63%), fine lines (31%), wrinkles (14%), and overall global assessment (43%). Facial swabbing confirmed an increase in topical HA at week 6 (p = 0.04), accounting for the enhanced skin appearance, but there was no statistically significant increase in IL-1a, indicating no product irritation. CONCLUSION: Topical HA in a serum formulation provides excellent skin hydration, as demonstrated through clinical, photographic, chemical, and instrumental assessments.

Vehicles for Drug Delivery and Cosmetic Moisturizers: Review and Comparison.

Many dermatological conditions, such as eczema and psoriasis, are treated with topical therapeutic products. Instead of applying the active drug directly onto the skin, it is combined with a vehicle to aid in its delivery across the stratum corneum (SC) and into deeper regions of the skin, namely the epidermis and dermis. Absorption into the systemic circulation is minimized. Topical vehicles are also used as cosmetic moisturizers (often termed emollient therapy) to ameliorate dry skin, which is a cornerstone of the management of various dermatological conditions, including xerosis, eczema, psoriasis, and aging. The most common topical vehicles include ointments, creams, gels, and lotions, among others. It is crucial that topical vehicles are chosen based upon the size and properties (wet/dry, mucous/non-mucous, healthy/diseased) of the skin to be treated in order to optimize application and contact of the product with the skin, as this can have profound impacts on potency, efficacy, and patient compliance. This review examines common topical vehicles used for drug delivery and cosmetic moisturizers, including their formulation, advantages and disadvantages, and effects on the skin. The unique rules imposed by governing regulatory bodies in Australia and around the world, in terms of topical product claims, are also briefly examined.

Particulate matter emissions of four types of one cigarette brand with and without additives: a laser spectrometric particulate matter analysis of secondhand smoke.

OBJECTIVE: Inhaled particulate matter (PM) in secondhand smoke (SHS) is deleterious for smokers and non-smokers. Different additives in cigarettes might effect the amount of PM. This study aimed to assess the influence of additives on the PM emissions from different cigarette types in SHS. DESIGN: An experimental study of PM measuring in SHS of cigarettes without exposition of any person. METHOD: The concentrations of PM (PM10, PM2.5 and PM1) in SHS of four different types of cigarettes of the brand Lucky Strike, two types with additives (Original Red, Original Blue) and two types without additives (Straight Red, Straight Blue), in comparison to the reference cigarette 3R4F were analysed. An automatic environmental tobacco smoke emitter generated SHS in an enclosed space with a volume of 2.88 m3. PM was measured with a laser aerosol spectrometer (Grimm model 1.109). Afterwards, the measuring values of the four Lucky Strike brands and the reference cigarette were statistically evaluated and visualised. RESULTS: Lucky Strike Straight Blue, a cigarette type without additives and lower tar amount, showed 10% to 25% lower PM mean values compared with the other tested Lucky Strike products, but 21% (PM1) respectively 27% (PM2.5,PM10) higher mean values than the reference cigarette. The PM mean of all measured smoke-free baseline values (clean air) was 1.6 µg/m³. It increased up to about 1800 µg/m³ for the reference cigarette and up to about 3070 µg/m³ for the Lucky Strike Original Blue. CONCLUSIONS: The findings of this study show the massive increase of PM amount by smoking cigarettes in enclosed spaces and suggest that additives in tobacco products increase the PM amount in SHS. For validation, further comparative studies are necessary focusing on the comparison of the PM concentration of cigarettes with and without additives. IMPLICATIONS: Due to the exposure to SHS, 890 000 people die each year worldwide. PM in SHS endangers the health of both non-smokers and smokers. This study considers the effect of additives like aromatics and humectant agents in cigarettes on PM in SHS. Do additives in tobacco products increase the amount of PM?

Assessment of the moisturizing properties of a magnetic mask containing iron oxide particles.

BACKGROUND: Moisturizer is an important component of many cosmetic products. It helps to maintain the skin's integrity and its barrier functions. Recently, magnetic masks that seek to improve the properties of the skin have been developed and have become a new cosmetic trend. However, scientific proof of their stated properties is lacking. AIMS: To test whether iron oxide contained in a face mask with magnetic properties in an oily matrix with a freeze-dried aloe-vera base increases moisturization of the skin and improves skin barrier function. METHODS: Formulations were prepared containing an oil phase (67.3% wt.) and a solid phase (32.7% wt.). The moisturizing properties of the mask were tested by measuring in vivo electrochemical impedance spectroscopy, contact angle, and visual appearance. Meanwhile, human panel tests were performed to evaluate the sensory perception of potential users. RESULTS: The moisturizing effect of the iron oxide mask is clearly superior to that of the other tested samples. Water retention and low transepidermal water loss (TEWL) were evidenced for the iron oxide magnetic mask. Its occlusive action on the skin resulted in larger water contact angles and enhances the barrier effect. A favorable sensory perception on the part of the users was obtained for the iron oxide magnetic mask. CONCLUSION: The presence of iron oxide and the magnetic property of the mask enhance occlusive behavior, diminishing the TEWL. Sensory analysis of the iron oxide magnetic mask performed by human panel tests shows that they possess characteristics including neutral odor, and easy, pleasant-feeling application.

LC-MS/MS Analysis of Sugars, Alditols, and Humectants in Smokeless Tobacco Products.

Globally, smokeless tobacco (ST) includes a wide array of chemically diverse products generally used in the oral cavity. Although ST has been widely investigated, this study was undertaken to determine the levels of sugars (mono- and di-saccharides), alditols, and humectants present in major ST categories/subcategories by using high performance liquid chromatography coupled with a triple quadrupole mass spectrometer (HPLC-MS/MS). The products studied included chewing tobacco (loose leaf, plug, twist), US moist snuff, Swedish snus, creamy snuff, dry snuff, dissolvable tobacco products, and tobacco-coated toothpicks. The highest mean sugar level was detected in chewing tobacco (9.3-27.5%, w/w), followed by dissolvable tobacco (2.1%); all other products were lower than 1%. Creamy snuff had the highest mean alditol levels (22.6%), followed by dissolvable tobacco (15.4%); all others had levels lower than 1%. The detected mean humectant levels ranged from non-detectable to 5.9%. This study demonstrates the broad chemical diversity among ST. This research may aid researchers and public health advocates investigating the exposures and risks of ST. [Beitr. Tabakforsch. Int. 28 (2019) 203-213].

Dans l'ensemble, le terme de tabac sans fumée (TSF) recouvre une large gamme de diverses substances chimiques consommées, en règle générale, par la cavité buccale. Malgré les vastes analyses déjà consacrées au TSF, la présente étude fut entamée dans le but de déterminer les niveaux de sucres (mono- et disaccharides), de sucres-alcools et d'humectants présents dans les principales catégories/sous-catégories de TSF à l'aide de la chromato-graphie en phase liquide à haute performance couplée à une spectrométrie de masse à triple quadripôle (HPLC-MS/MS). Les produits analysés inclurent le tabac à chiquer (feuilles en vrac, tablette, corde), du tabac à priser humide américain, du snus suédois, du creamy snuff, du tabac à priser sec, des produits de tabac soluble et des cure-dents à la nicotine. Le niveau médian de sucres le plus élevé fut détecté dans le tabac à chiquer (9,3­27,5%, p/p), suivi du tabac soluble (2,1%); tous les autres produits présentèrent des niveaux inférieurs à 1%. Le creamy snuff présenta les niveaux médians de sucre-alcool les plus élevés (22,6%), suivi du tabac soluble (15,4%); tous les autres produits affichèrent des niveaux inférieurs à 1%. Les niveaux médians d'humectants détectés oscillèrent entre non-détectable et 5,9%. La présente étude démontre la grande diversité chimique parmi les formes de TSF et peut aider les chercheurs et les intervenants en faveur de la santé publique à explorer les degrés d'exposition et les risques du TSF. [Beitr. Tabakforsch. Int. 28 (2019) 203­213].

Skin hydration is significantly increased by a cream formulated to mimic the skin's own natural moisturizing systems.

BACKGROUND: Moisturizers are topical products designed to improve and maintain the skin barrier function and to help prevent dry skin. MATERIALS AND METHODS: A new moisturizer (Ceramide cream) was formulated containing ingredients which mimic the skin's own natural moisturizing systems. Corneometry was performed at baseline, 2, 4, 6 and 24 hours following a single application of Ceramide cream to healthy skin, and compared to three reference moisturizers available over-the-counter, and placebo. Transepidermal water loss (TEWL) was also measured following a single application of Ceramide cream compared to baseline, and its safety was assessed by repeat insult patch test, ophthalmologist and pediatric testing. RESULTS: A single topical application of either the Ceramide cream or the three reference moisturizers resulted in a significant increase in skin hydration over time (P<0.001). The placebo cream did not significantly increase skin hydration at any time point. At 24 hours post-application, skin hydration measured for Ceramide cream was significantly greater (P<0.05) than that measured for all three of the reference moisturizers tested. Ceramide cream was also found to significantly decrease TEWL (P<0.001) over 24 hours, and was shown to be non-sensitizing to the skin of both adults and children and non-irritating to the skin, eyes and related eye area. CONCLUSION: Ceramide cream increases skin hydration and improves barrier function which may make it suitable for use on dry skin.

Influence of glycerol and an alternative humectant on the immediate and 3-hours bactericidal efficacies of two isopropanol-based antiseptics in laboratory experiments in vivo according to EN 12791.

BACKGROUND: Guidelines for hand hygiene recommend the use of alcohol-based hand rubs containing humectants in order to improve dermal tolerance. However, the bactericidal efficacy of pre-surgical hand rubs is negatively affected by the WHO-recommended humectant glycerol, especially the 3-h efficacy. The aim of this study was to investigate whether replacing glycerol as humectant increases the bactericidal efficacy of surgical hand rubs based on isopropanol (75%, wt/wt). MATERIAL AND METHODS: The efficacy of 3 and 5 min applications of a modified WHO II-formulation (containing lower glycerol concentrations) and the TPH 5766 hand rub which contains a new humectant (containing ethylhexylglycerin, dexpanthenol and a fatty alcohol) were compared to the European Norm 12,791 reference (n-propanol, 60%, vol/vol) immediately following and 3 h after application. RESULTS: Immediately after application both isopropanol-based surgical rubs approximated the performance of the reference. The 3-h effect of the modified WHO II-formulation was found to be less efficacious than the EN 12791, showing a 30% decrease in log10 reduction values. The 3-h post application effect for the TPH 5766 hand rub was found to not be different from EN 12791. CONCLUSION: Based on our data, the bactericidal efficacy of isopropanol-based surgical hand rubs can best be obtained if glycerol is not used in the formulation. Unlike glycerol, a humectant comprised of ethylhexylglycerin, dexpanthenol and a fatty alcohol was found not to decrease hand rub effectiveness. Further investigation of the bactericidal efficacy of other humectants is necessary and may prove useful.

The cosmetic and dermatological potential of keratin hydrolysate.

BACKGROUND: Although keratin hydrolysates have become established as standard components in hair and nail cosmetics, studies on the moisturizing effects of keratin hydrolysates do not appear among contemporary literature. OBJECTIVES: To test if adding keratin hydrolysate into an ointment base increases hydration of the skin and improves skin barrier function, or diminishes trans-epidermal water loss. METHODS: Formulations were prepared containing 2%, 4%, and 6% keratin hydrolysates (based on weight of the ointment base). The moisturizing properties of keratin hydrolysates were tested by measuring skin hydration, trans-epidermal water loss and skin pH; measurements were carried out at intervals of 1, 2, 3, 4, 24, and 48 h. Testing was conducted on 10 women. RESULTS: As regards hydration, adding 2% keratin hydrolysate to the ointment base is optimal, as an increase of 14%-23% occurs in hydration of the stratum corneum. For trans-epidermal water loss, adding 4% KH to the ointment base is preferential, as this triggers a 26%-46% decrease in trans-epidermal water loss. CONCLUSIONS: Keratin hydrolysate acts as a humectant (it binds water from lower layers of the epidermis to the stratum corneum) as well as an occlusive (it reduces trans-epidermal water loss). The highly favorable properties of keratin hydrolysates are attributed to the wide distribution of keratin hydrolysates molecular weights; low-molecular weight fractions easily penetrate the SC, while high-molecular weight fractions form a protective film on the epidermis. Adding keratin hydrolysates to the ointment base did not cause phase separation even after 6 mo storage.

An isotope dilution ultra high performance liquid chromatography-tandem mass spectrometry method for the simultaneous determination of sugars and humectants in tobacco products.

CDC's Division of Laboratory Sciences developed and validated a new method for the simultaneous detection and measurement of 11 sugars, alditols and humectants in tobacco products. The method uses isotope dilution ultra high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) and has demonstrated high sensitivity, selectivity, throughput and accuracy, with recoveries ranging from 90% to 113%, limits of detection ranging from 0.0002 to 0.0045µg/mL and coefficients of variation (CV%) ranging from 1.4 to 14%. Calibration curves for all analytes were linear with linearity R2 values greater than 0.995. Quantification of tobacco components is necessary to characterize tobacco product components and their potential effects on consumer appeal, smoke chemistry and toxicology, and to potentially help distinguish tobacco product categories. The researchers analyzed a variety of tobacco products (e.g., cigarettes, little cigars, cigarillos) using the new method and documented differences in the abundance of selected analytes among product categories. Specifically, differences were detected in levels of selected sugars found in little cigars and cigarettes, which could help address appeal potential and have utility when product category is unknown, unclear, or miscategorized.

Experimental study on the thermal decomposition and combustion characteristics of nitrocellulose with different alcohol humectants.

Although the thermal behaviors including thermal instability of nitrocellulose (NC) and its mixtures with some humectants have been comprehensively examined previously in the literature, their combustion characteristics have not been systematically studied. To address the issue, the combustion properties of NC with alcohol humectants are investigated by the means of the ISO 5660 cone calorimeter. Two kinds of NC-humectant mixtures with 30wt.% isopropanol and 30wt.% ethanol, respectively, were employed as samples. The tests were conducted under different external radiations, ranging from 0-15kW/m2. The experimental results indicate that the external radiation positively influences the peak heat release rate (HRR) intensity and the maximum mass loss rate (MLR), while the total heat release (THR) decreases with the elevated external radiation. Comparatively, the sample with isopropanol exhibits a higher fire risk, characterized by the higher peak HRR, THR and maximum MLR. Auxiliary investigating methods, including Scanning Electron Microscopy and Differential Scanning Calorimeter-Thermal Gravimetric Analysis, were applied to examine the micro structure and thermal behavior of NC-humectant mixtures. The results helped to explain the burning characteristics observed in the cone calorimeter tests.

Performance Boosting of Flexible ZnO UV Sensors with Rational Designed Absorbing Antireflection Layer and Humectant Encapsulation.

Flexible ZnO thin film UV sensors with 3 orders of magnitude improvement in sensitivity and 2 orders of magnitude acceleration in speed are realized via light absorption efficiency enhancement and surface encapsulation. Devices are constructed on polyethylene substrate incorporating morphology controlled ZnO nanorod arrays (NRAs) as absorbing antireflection layers. By adjusting the morphology of ZnO NRAs, the light absorptance exceeds 99% through effectively trapping incident photons. As a result, the sensitivity of the UV sensor reaches 109 000. Moreover, a mechanism of competitive chemisorption between O2 and H2O at oxygen vacancy sites is proposed to explain the phenomenon of the speed acceleration in moist environment. A new approach of humectant encapsulation is used to make H2O participant rapid processes dominant for speed acceleration. Two orders of magnitude speed enhancement in reset time is achieved by polyethylene glycol encapsulation. After a total 3000 cycles bending test, the decay in the responsivity of UV sensor is within 20%, indicating good mechanical stability. All these results not only demonstrate a simple, effective and scalable approach to fabricate high sensitive and fast response flexible ZnO UV sensors, but also provide meaningful references for performance boosting of photoelectronic devices based on other oxide semiconductors.

Water Sorption Isotherms of Surfactants: A Tool To Evaluate Humectancy.

Fundamental experimental data for moisture absorption of non-ionic polydisperse surfactants with differing ethylene oxide (EO) content and variable aliphatic portions were measured at relative humidities between 0 and 95% at 25 °C. Remarkable differences in moisture absorption were observed between surfactant classes but also within one series of surfactants differing in either EO content or the long-chain aliphatic fraction. Both the EO units as well as the entire molecular structure, including also the lipophilic domain, were discussed to account for the humectant activity of surfactants. Water sorption isotherms showed an exponential shape, which was argued to be associated with the formation of a "free" water domain. These humectant properties might be relevant to the behavior of a foliar-applied spray droplet of agrochemical formulation products because the uptake of active ingredients will be enhanced as a result of deferred crystal precipitation.

Effects of Replacing Sucrose with Various Sugar Alcohols on Quality Properties of Semi-dried Jerky.

The objective of this study was to investigate the effects of replacing sucrose with sugar alcohols (sorbitol, glycerol and xylitol) on the quality properties of semi-dried jerky. Total 7 treatments of jerkies were prepared as follows: control with sucrose, and treatments with 2.5 and 5.0% of sucrose replaced by each sugar alcohol, respectively. Drying yield, pH, water activity, moisture content, shear force, myofibrillar fragmentation index (MFI), 2-thiobarbituric acid reactive substance (TBARS) value, sugar content, and sensory evaluation were evaluated. Xylitol slightly decreased the pH when compared to the other sugar alcohols (p>0.05). The water activity of the semi-dried jerky was significantly reduced by treatment with glycerol and xylitol (p<0.05). The moisture content of semi-dried jerky containing various sugar alcohols was significantly higher than that of the control (p<0.05), while replacing sucrose with glycerol yielded the highest moisture content. The shear force of semi-dried jerky containing sugar alcohols was not significantly different for the sorbitol and glycerol treatments, but that replacing sucrose with 5.0% xylitol demonstrated the lowest shear force (p<0.05). The TBARS values of semi-dried jerkies with sugar alcohols were lower than the control (p<0.05). The sugar content of the semi-dried jerkies containing sorbitol and glycerol were lower than the control and xylitol treatment (p<0.05). In comparison with the control, the 5.0% xylitol treatment was found to be significantly different in the sensory evaluation (p<0.05). In conclusion, semi-dried jerky made by replacement with sugar alcohols improved the quality characteristics, while xylitol has applicability in manufacturing meat products.

Comparative measurement of hydration effects of herbal moisturizers.

Improvements of skin hydration properties by the use of polyherbal moisturizers are the recent advances in cosmetic preparations to avoid the harmful effects of chemical moisturizers. The main aim of the study was to establish selection preference of different available marketed herbal moisturizers on the basis of the efficiency of constituents for their hydration effects. The criteria for the selection of formulations were presence of herbal constituents, wheat germ oil and Aloe vera extract. Initially, physiochemical and psychometric studies were performed to visualize the compliance of moisturizers with the skin. The clinical study was carried out in six groups of six healthy human volunteers (aged 20-25 years) each applying moisturizers twice daily over a period of 3 weeks in their forearm. The skin properties measured were conductance, glow and appearance. The results indicated that all the moisturizers show moisturizing effect in a time-dependent pattern and the maximum increase in skin conductance was 168.125 and 165.24% for A2 and A1, respectively. Ranking of moisturizers based on conductance as well as physicochemical analysis is A2 > A1 > A4 > A3 > A5 > A6. It was found that the formulation A2 having wheat germ oil, Aloe vera extract and turmeric extract in combination showed best results due to their synergistic effect and wheat germ oil or Aloe extract, when present separately produced skin hydration to lesser extent.