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Influence of vitamin E acetate on stratum corneum hydration
Abstract
The influence of vitamin E (tocopherol, CAS 10191-41-0) on stratum corneum hydration was tested in O/W and W/O emulsions. Additionally, the O/W emulsion was used in an in vivo/in vitro method to gravimetrically obtain evidence concerning the water-binding capacity of the stratum corneum. In the W/O emulsion, 2.5%, 5%, and 7.5% vitamin E were compared. With both types of emulsions, vitamin E increased the stratum corneum hydration statistically significantly (p = 0.0002). In addition, we could provide evidence of an enhanced water-binding capacity after treatment with vitamin E (p = 0.05). For the hydrating effect of vitamin E. its concentration is of importance. The optimum concentration turned out to be 5%.
... For vitamin E alone, hydro-alcoholic solution of alpha-tocopherol showed a reduction of UV-induced erythema in the epidermis [62] and the reduction on the number of epidermal sunburn cells. While O/W and W/O emulsions containing alpha-tocopherol acetate increased skin hydration and water-binding capacity in the stratum corneum [63]. Vitamin E is also used as coadjutant in other topical products to improve physical-chemical characteristics or to donate different effects. ...
... Thus, the topical use of vitamin E is adequate for its recognized antioxidant and protective activities, favoring the improvement of the skin barrier due to its lipophilic character and also, effectively avoiding lipid peroxidation by protecting cell membranes from the action of free radicals [103]. Gehring et al. [63] evaluated the hydration capacity of the stratum corneum by the use of vitamin E (5%) in water/ oil and oil/water emulsions, demonstrating moisturizing activity in the stratum corneum, in addition to providing indications that indicate retention of water in the stratum corneum. Gonullu and collaborators [104] also report that the topical use of vitamin E for a period of two to four weeks can improve the ability of water to retain in the skin, favoring hydration. ...
Vitamins are part of the antioxidant system of human skin, and are detectable in different layers, so the topical application can be an alternative to maintain the functionality of the system. The capacity of the antioxidant gradient of keratinocytes is associated with attenuation of the action of related free radicals in both esthetics and health. These problems arise from extrinsic aging and are related to the risk of cancer. Vitamin E has been proven to have antioxidant and moisturizing properties in the skin and can protect against the damage of UVB radiation, with emphasis on the reduction of acute erythema and photoaging. The choice for the use of topical vitamin E, compared to the oral is given by the safety as mild irritation and it has potential for multifunctional topical formulations. The purpose of the chapter is to review the topical use of formulations with vitamin E, addressing the development, safe use and evaluation of effectiveness.
... Tocopheryl acetate is a free radical scavenger that may reduce DNA damage and the rate of death in keratinocytes [6]. In addition, it can enhance stratum corneum hydration [7] and reduce skin roughness. ...
... These results are similar to the ones obtained by Darvin et al. [7] who observed that an optimal mixture of antioxidants protected the formulations against oxidation, extending their working life and the protection of the skin against the negative action of produced free radicals. Benevenuto et al. [27] also showed that formulations containing vitamin A palmitate with UV-filters combined with some photostabilizers had better protective effects on hairless mice skin than the ones without any photostabilizer. ...
Chemically stable ester derivatives of vitamins A, C and E have become a focus of interest for their role in the satisfactory results in skin aging treatments. Accordingly, the aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing 1% retinyl palmitate, ascorbyl tetraisopalmitate and tocopheryl acetate, alone or in combination. In the studies of physical stability, a Brookfield rheometer was used to determine rheological behavior of formulations containing the vitamins. Chemical stability was determined by HPLC on a Shimadzu system with UV detection. Results showed that formulations had pseudoplastic behavior and that vitamins did not alter their apparent viscosity and thixotropy. In the chemical stability studies, first-order reaction equations were used for determinations of the shelf-life of vitamins derivatives considering a remaining concentration of 85%. Combined vitamins in a single formulation had a slightly lower degradation rate as compared to different preparations containing only one of the vitamins. Considering that many cosmetic formulations contain vitamin combinations it is suggested that the present study may contribute to the development of more stable formulations containing liposoluble vitamins.
... Excipients were selected on the basis of their characteristics and properties. It is well known that vitamin E has a crucial role in defending cell membranes by free radicals which cause degradation of lipids, and acts by inhibiting protein kinase C activity and mediating the collagenase expression [6,7]. In particular, esters of vitamin E are often used in topical products, because these are extremely stable and easily bio-converted to vitamin E. Hence, in this study, vitamin E acetate was selected as lipophilic phase [8]. ...
Microemulsions are optically nanosized emulsions, isotropic and thermodynamically stable. They represent versatile drug delivery systems with high potential because can be administered through all routes. In the present study, we report on the formulation of a microemulsion made with glycerol (2.25%), Labrasol (20.25%) vitamin E acetate (2.50%), and water (75.00%), which was developed using the pseudo-ternary phase diagram. Globules of the microemulsion had PdI less than 0.25 and size of about 17 nm, evaluated by DLS analysis. These values did not change after loading khellin, a natural lipophilic molecules with interesting biological activities, used as a model of lipophilic drug. Carboxymethyl cellulose was selected as gelling polymer to obtain a microemulgel. Viscosity was 22,100.0±1555.6 mPas·s at 21±2°C, while it was 8,916.5±118.1 mPas·s at 35±2°C, remaining stable over time. Khellin recovery was 93.16±4.39% and it was unchanged after 4 weeks of storage (93.23±2.14%). The pH was 6.59±0.19 and it was found 6.42±0.34 at the end of the storage lifetime. The diffusion of khellin from the developed formulation was prolonged over an extended period. Based on overall results and due to the dermatological properties of the ingredients of the formulation, the developed microemulgel loaded with khellin is very promising and suitable for skin care applications.
... Retinyl palmitate has a beneficial effect on dry and rough skin epithelization and abnormal keratinization [125]. Vitamin C enhances skin hydration [126]. Tocopheryl acetate has a free radical scavenger activity, decreases DNA damage, keratinocyte death [127], skin roughness, and improves stratum corneum hydration [128]. ...
Nowadays, much attention is paid to issues such as ecology and sustainability. Many consumers choose "green cosmetics", which are environmentally friendly creams, makeup, and beauty products, hoping that they are not harmful to health and reduce pollution. Moreover, the repeated mini-lock downs during the COVID-19 pandemic have fueled the awareness that body beauty is linked to well-being, both external and internal. As a result, consumer preferences for makeup have declined, while those for skincare products have increased. Nutricosmetics, which combines the benefits derived from food supplementation with the advantages of cosmetic treatments to improve the beauty of our body, respond to the new market demands. Food chemistry and cosmetic chemistry come together to promote both inside and outside well-being. A nutricosmetic optimizes the intake of nutritional microelements to meet the needs of the skin and skin appendages, improving their conditions and delaying aging, thus helping to protect the skin from the aging action of environmental factors. Numerous studies in the literature show a significant correlation between the adequate intake of these supplements, improved skin quality (both aesthetic and histological), and the acceleration of wound-healing. This review revised the main foods and bioactive molecules used in nutricosmetic formulations, their cosmetic effects, and the analytical techniques that allow the dosage of the active ingredients in the food.
... vitamin E is the commonly used ingredient in many cosmetic as well as in pharmaceutical and nutraceutical preparations. In marketed Aloe-based pharmaceuticals and nutraceuticals many stabilizing and antioxidant agents such as vitamin E, vitamin C and vitamin A are commonly used in Aloe-based products(29). Thus, a parallel standard method for QA/QC purpose is needed to be established. ...
Pharmacological activity of Aloe vera is known for hundreds of years, but a precise and well-established characterization method for all kinds of pharmaceutical formulations is still a challenging task. In the present
study, a simple, user- friendly, sensitive, precise, accurate, robust and reproducible method has been developed based on reverse phase-high performance liquid chromatography (RP-HPLC). The RP-HPLC method has been developed, standardized and validated utilizing the Aloe marker compounds viz., Aloin A, Acemannan and Aloeemodin that is present in various Aloe vera varieties. The total polyphenolic content (TPC) and total flavonoid
content (TFC) were estimated spectrophotometrically and an in-vitro antioxidant study was also performed to standardize the potential of Aloe vera using assays viz. DPPH (2,2- diphenyl-1-picrylhydrazyl radical scavenging), NO (nitric oxide) scavenging potential, FRAP (ferric reducing antioxidant power) and TAC (total antioxidant capacity). Simultaneously, tocopherol acetate was also estimated in commercially manufactured pharmaceutical products with the help of the previously standardized HPLC method in our laboratory. Separation of the singular active ingredient of Aloe vera was achieved by using an isocratic mode of acetonitrile and water (70:30 v/v) by using a reversed-phase C18 column as stationary phase in a high-performance liquidchromatography system employing photodiode array detector (PDA plus detector) with a flow rate of 1.0 ml/min. The detection limit of active compound of Aloe species was found to be in the range of 0.00020 to 0.00051 µgL-1 (20 µL injection of each for five times). The quantitative method of Aloe vera extracts standardized vis-à-vis both with peel (AL-P) and without peel (AL-WP) form gives robust, precise (% RSD 1.13-3.84) and accurate results. This method is suitable for the detection of major pharmacologically active compounds present in Aloe vera-based pharmaceuticals and nutraceuticals.
... Цех фасовки туалетного мыла вырабатывает продукцию за счет механической обработки высококачественного ядрового мыла (который состоит в основном из натриевых солей натуральных и синтетических жирных кислот) с добавлением красителей, ароматизирующих и отбеливающих веществ (или без них), пластификаторов, антиоксидантов и других компонентов, улучшающих потребительские и косметические свойства мыла, а также с добавлением антисептических и смягчающих средств (или без них) [8]. ...
In the course of the work, the technology of obtaining toilet soap with cosmetic properties was improved; samples of soap with the introduction of physiologically functional substances into the composition of the formulation components were experimentally obtained in order to preserve the initial physiologically active properties. The technological process of preparing the basic toilet soap periodically indirect method of neutral fats includes the following stages: caustic saponification of the fat set; grinding soap base; upholding of the soap base; draining the soap base; ennoblement of a soapy glue. Saponification of the main fat raw material is carried out in the soap boiler and can be produced both on the rest of the soap from the previous cooking, and using the pre-refined adhesive residue from the previous brews. Grinding of the soap base is carried out by hot water 80–90 ?, dry table salt or solution of caustic alkali, which are delivered in separate portions at boiling of the mass with a steaming steam, in an amount necessary for mass separation during grinding into the core (toilet base) and saponified adhesive. The sedimentation of the soap base is made after grinding is performed to separate the mass in the grinding process into the core (toilet base) and the sapwood glue. The temperature of the soap mass before settling must be at least 100 °C. The settling time is not less than 24 hours. The preparation of the core is carried out in a soap boiler. Prefabricated soap of toilet soap is heated to a boil with a hot steam. Then produce a high level of sapper adhesive with dry table salt, which is introduced in the amount necessary to separate the mass into a core and a flushing liquor. After each portion of the salt is injected, the soap mass is boiled for 15–20 minutes until completely dissolved and uniformly distributed in the mass. Salting is considered complete if the soap in the cauldron acquires a granular structure and in the sample on the spatula the kernels of the nucleus are clearly visible, between which the flaked lye flows.
... Vitamin E is recognized as the best antioxidant of biological membranes [35] and it reduces DNA damage and skin roughness [36]. The antioxidant diffuses the ROS into human tissue decelerating the extrinsic skin ageing [37]. ...
Non-invasive in vivo human studies have always been of great importance owing to their advantages over the invasive studies. This research work also presents such a non-invasive study dealing with the penetration of two vitamin derivatives: retinyl acetate and alpha-tocopheryl acetate, into the stratum corneum of two groups of study participants categorized based on age as young (average age of 24.1 ± 3.3 years old) and elderly groups (average age of 68 ± 5.8 years old). According to the increase of age it is expected that intrinsic alterations may occur in the stratum corneum. Understanding these alterations is relevant to the knowledge of the differences between stratum corneum as a function of age-dependence thus, leading to the development of new specific products for ageing. The penetration of these derivatives was semi-quantitatively analyzed using confocal Raman spectroscopic technique with 3510 Skin Composition Analyzer (River Diagnostics, Rotterdam, The Netherlands) with a diode laser of 785 nm wavelength and 26 mW power. The analysis was done in the extended fingerprint region (1800 - 400 cm−1) for the stratum corneum region of the skin considering the depths from surface up to 24 μm. The results of this study clearly indicated that these two vitamin derivatives penetrated significantly into the stratum corneum of both study groups and their penetration was mainly affected by the composition of SC and their physico-chemical properties. The penetration profile of the alpha-tocopheryl acetate displays significant statistical difference (p < 0.05) between groups from surface up to 12 μm.
... O α-tocoferol em concentrações de 0,05%-2% foi usado como antioxidante em preparações tópicas. Em altas concentrações (2-10%) o α-tocoferol pareceu promover benefícios na hidratação do estrato córneo (IDSON, 1978;GEHRING et al., 1998). O α-tocoferol puro e em preparações de α-tocoferol concentradas (10-20%) irritaram a pele humana, e causaram dermatite de contato e outros tipos de reações de hipersensibilidade imunológica foram reportados. ...
Orientadora : Mayumi Eliza Otsuka Sato Dissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Cięncias da Saúde, Programa de Pós-Graduaçăo em Cięncias Farmacęuticas. Defesa: Curitiba, 2006 Inclui bibliografia Área de concentraçăo: Insumos, medicamentos e correlatos
... Vitamin A palmitate acts on epithelization and on abnormal keratinization (MaiaCampos et al., 1999). Vitamin E acetate is a free radical scavenger and can reduce DNA damage and keratinocytes death (sunburn cell formation) (McVean and Liebler, 1997;Gaspar and Maia Campos, 2003) and also can enhance stratum corneum hydration and reduce skin roughness (Gehring et al., 1998). Tetra-isopalmitoyl ascorbic acid (VC-IP) releases vitamin C in physiological conditions and enhances cellular tolerance against UVB and reactive oxygen species as well as reduces the production of interleukin-1a and prostaglandin E2 (Ochiai et al., 2006). ...
Saccharomyces cerevisiae extract (SCE) is used in cosmetics since it can act in oxidative stress and improve skin conditions. This study investigated dermatological effects of cosmetic formulations containing SCE and/or vitamins A, C and E. The formulation studied was supplemented or not (F1: vehicle) with vitamins A, C and E esters (F2) or with SCE (F3) or with the combination of vitamins and SCE (F4). Formulations were patch tested on back skin of volunteers. For efficacy studies, formulations were applied on volunteers and transepidermal water loss (TEWL), skin moisture (SM), skin microrelief (SMR) and free radicals protection were analysed after 3h, 15 and 30 days of application. Volunteers were also asked about efficacy perception. It was observed that F4 provoked a slight erythema in one volunteer. All formulations enhanced forearm SM. Only F3 and F4 presented long term effects on SMR and showed higher texture values; F3 had the highest brightness values. Our results suggest that vitamins and SCE showed effects in SM and SMR. Only formulations containing SC had long term effects in the improvement of SMR. Thus, these kinds of evaluations are very important in cosmetics development to evaluate the best risk and benefit correlation.
Vit E is a collective term referring a group of 8 naturally occurring lipid-soluble molecules (homologs), of which 4 are tocopherols (α, β, γ, and δ tocopherols) and 4 are tocotrienols (α, β, γ and δ tocotrienols) [1]. Vit E was discovered in 1922 by Evans and Bishop, of the University of California in Berkeley, and the name “tocopherol” they proposed is derived from the Greek word “tocos” = offspring and the Greek verb “phero” = to bear, since the unknown till that time molecule was required to prevent fetal resorption in pregnant rats fed lard-containing diets that were easily oxidizable [2]. The -ol ending indicates its alcohol functional group. Tocopherol became known as the “antisterility vitamin”, but soon scientists realized that it had this effect only in rats.
Die topische Applikation von Vitaminen hat eine Große Bedeutung in der Behandlung von Hautalterungserscheinungen. So zählen Vitamin A und Vitamin C zu den am besten untersuchten Substanzen gegen Zeichen der Hautalterung. Ihre Wirksamkeit wurde auch in Plazebo-kontrollierten Studien bestätigt. Vitamin-A-Derivate gelten noch heute als Standard in der topischen Behandlung der Hautalterung. Voraussetzung für eine Wirksamkeit ist jedoch die erfolgreiche Penetration des Wirkstoffes aus der Grundlage in die Haut und eine ausreichende Konzentration der Substanz. Ob auch systemische Vitamingaben zur Prophylaxe und Behandlungen von Hautalterungserscheinungen sinnvoll sind, lässt die derzeitige Datenlage nicht erkennen. Neben minimal-invasiven Verfahren und konsequentem Lichtschutz stellen Vitamine als dermatokosmetische Wirkstoffe eine der wesentlichen Säulen in der Behandlung der extrinsischen und intrinsischen Hautalterung dar. Im Rahmen einer wissenschaft- lich fundierten Dermatokosmetik sind zur Evidenzbasierten Prüfung der Wirksamkeit weitere doppelblinde, randomisierte und Plazebo-kontrollierte Studien zur topischen wie systemischen Applikation von Vitaminen anzustreben.
Die Haut prägt wesentlich das äußere Erscheinungsbild unseres Körpers. Dafür sind Oberflächenstruktur, Spannung und der Hydrolipidfilm von Bedeutung. Eine glatte, straffe Haut ohne Faltenbildung gilt als Zeichen für Vitalität, Jugend und Frische und assoziiert das Bild von Gesundheit und Aktivität. Eine trockene, schuppende, spannungsarme, faltige Haut mit schwindendem Turgor erweckt den Eindruck von Unattraktivität und Vitalitätsverlust.
Seborrhoeic dermatitis is characterised by the occurrence of the lipophilic yeast M. furfur and the resulting inflammatory lesions of the skin. Therapy of seborrhoeic dermatitis therefore includes antifungal and anti-inflammatory measures. The active ingredient ciclopirox olamine reduces effectively the growth of M. furfur. In addition ciclopirox olamine has an anti-inflammatory effect and thus is especial useful in the treatment of seborrheic dermatitis. The prescription only and reimbursable medicinal product Sebiprox 1.5 % Solution contains 1.5 % ciclopirox olamine in an scalp convenient galenic and thus supports the compliance of patients suffering from seborrheic dermatitis of the scalp.
Non invasive aging treatment is very requested by dermatologic patients. There are a lot of active and very tolerated principles into cosmetic products. The most important nowadays are antioxidants, α-hydroxy acids and retinoids. Antioxidants are active against environmental stress, α-hydroxy acids provoke tissue reparation via chemical flogosis and retinoids act by receptorial link and genic stimulation. The target are epidermis and dermis mechanisms and association of two or more molecules is important for wide activity on cutaneous aging and photoaging.
Acute and chronic exposure to sun rays have been linked to several types of skin damage, including sunburn, photoaging, photocarcinogenisis, and photoimmunosupperssion. One likely hypothesis for the genesis of these skin pathologies is believed to be the formation of free radicals. This suggestion has led to the supplementation of antioxidants such as x-tocopherol (vitamin E) in various cosmetic skin preparations. Vitamin E is now considered essential for the stabilization of biological membranes, x-tocopherol is commonly used as its prodrug ester. This article reviews the chemistry of vitamin E, its cutaneous biological functions, its prodrug forms and their metabolism into the active form of free vitamin E, and the effect of varying formulations on the percutaneous absorption of vitamin E.
Gli antiradicali topici, per la maggior parte costituiti da vitamine, minerali ed estratti vegetali, possiedono proprietà che, in vitro, si rivelano interessanti nella prevenzione dell’invecchiamento, nella protezione solare, nella carcinogenesi cutanea, nei disturbi pigmentari e nell’idratazione. Oggi, tutto fa pensare che essi siano efficaci in vivo, ma resta da dimostrare che nell’uomo queste stesse sostanze siano in grado di erogare nella cute dosi adeguate, che abbiano come conseguenza delle modificazioni istologiche e un miglioramento clinico.
Tocopherol (T) and tocopherol acetate (TA) are widely used ingredients in cosmetics. The present study was carried out to evaluate the content and stability of T/ TA contained in marketed and experimental cosmetic formulations. T/TA in four marketed products (A-D) and two experimental formulations (F1and F2), stored under different temperatures, were investigated by HPLC. The results indicated variable degree of stability according to the storage temperature and product type. The stability progressively decreased upon storage at 37 °C > 25 °C > 2-8 °C. TA containing formulations showed higher stability compared to T. Further studies are in progress to optimize such formulations for improving vitamin E stability and transdermal permeation to eventually achieve the expected therapeutic and cosmetic outcomes. © 2009, JGPT.
To investigate the ability of α-tocopherol acetate (TA) and α-tocopherol (T), widely used ingredients in cosmetics, to cross the epidermal barrier using the neonatal rat as a model.
The content of T and TA in four marketed products (A-D) and two experimental formulations (F1, F2) was investigated by HPLC. An in vitro permeation study was performed in neonatal rat epidermis using diffusion cells. In vivo permeation was studied in neonatal rats after repeated application of the products and analysis of T and TA in the stratum corneum/deeper skin layers.
Variable contents of TA were found in the marketed products (0.12-0.53%). No vitamin permeation was detected through the stratum corneum as in vitro biological barrier after 4 h. No detectable T and TA were seen in the in vivo permeation study in the epidermis. Variable degrees of drug penetration (4.3-12.6%) of the applied dose into the deeper skin layers were observed, depending on the formulation. In vivo application of TA-containing preparations did not result in any transformation of TA into T under the described experimental conditions.
TA and T exhibited variable skin penetration and TA did not transform into T under the experimental conditions. The data underscored the need for further studies to optimize such formulations to improve vitamin E transdermal permeation and eventually achieve the expected cosmetic/therapeutic outcome.
A specific HPLC method, with an RP-C-18 column and a UV detector, for simultaneous determination of vitamin E (tochopherol, T)/T acetate (TA) in four commercial and two experimental cosmetic products is described. Three solvent systems for extraction of T/TA were assessed: isopropyl alcohol; 10:90 v/v hexane-methanol mixture (method 1); and methanol alone (method 2). The procedure was accurate, as indicated by high recovery (97.8-101.8% and 100.1-102.5% for T and TA, respectively) and precise (RSD was only 0.9-3.26% and 0.73-3.35% for T and TA, respectively). The limits of detection for T and TA were 200 and 300 ng/ml, respectively, while the limits of quantitation were 250 and 400 ng/ml, respectively. The range of reliable quantification was 5-50 μg/ml. Isopropanol as solvent resulted in a turbid extract. Method 1 and method 2 of extraction showed high recovery (98.5-99.9% and 97.2-97.9% for T and TA, respectively). After a few weeks of analysis, method 1 resulted in retention time drift, peak broadening, non-reproducible results, and progressive loss of HPLC-column integrity. Methanol alone (method 2) was equally as efficient as that of the mixture of methanol with 10% hexane (method 1) for extraction. The described analytical procedure proved to be accurate, precise, and suitable for simultaneous determination of T and TA in real commercial cosmetic products.
1. Eczema impairs the quality of life of both sufferers and carers. 2. Emollients play a major part in the skin care of eczema. 3. Care needs to be taken to ensure correct strength and dose of topical steroids when used. 4. All practitioners need to be aware of the range conventional and complementary therapies on offer to eczema sufferers.
The effect of delivery system on the permeation and metabolism of alpha-tocopheryl acetate (alpha-TAc) was studied in micro-Yucatan pig skin, which closely resembles human skin. Various alpha-tocopheryl acetate formulations, including a simple isopropyl myristate (IPM) solution, an o/w emulsion, microemulsions, which differed in their oily phase content, and alcoholic and hydroalcoholic gels were made. A suitable HPLC method was developed and validated to separate and quantify alpha-TAc and alpha-tocopherol (alpha-T). Dulbecco's modified phosphate-buffered saline with 3% bovine serum albumin (DMPBS-BSA 3%) served as the receptor media to ensure tissue viability and to maintain skin conditions. Finite doses (5 microl) of the formulations were applied to viable pig skin using a statistically approved randomized complete block design. Data were analyzed using Tukey's studentized range test, and interday variability was estimated using an F-test. About 70% of the active was recovered from the wash, representing the amount adhering to the surface of the skin. alpha-TAc underwent metabolism in pig skin to the active antioxidant, alpha-T. The identity of the HPLC peaks were confirmed by spiking studies using known standards. The extent of metabolism was found to be formulation-dependent. No alpha-T was, however, detected in the stratum corneum. A higher extent of metabolism was obtained for the IPM solution, a microemulsion containing IPM as the oily phase, and the hydroalcoholic gel, when calculated based on the percent of total alpha-TAc permeated in the viable skin. Metabolism occurred in pig skin to the extent of 15-20% in terms of the total amount of alpha-TAc permeated in the viable skin and stratum corneum. Thus the topical delivery and metabolism of alpha-TAc were found to be dependent on formulation.
The objective of this research was to investigate the effect of concentration and delivery system on skin permeation of alpha-tocopherol (alpha-T). Also, the addition of sunscreens and oleic acid on alpha-T permeation was studied using an in vitro micro-Yucatan pig skin model. Various delivery systems of alpha-T (1%) were formulated, which included simple solution, gels, emulsions, and microemulsions. The experimental design chosen for this study was a statistical randomized complete block design. alpha-T delivery was proportional to its concentration. The hydroalcoholic gel delivered significantly higher amounts of alpha-T into the receptor than the other gels used. A microemulsion containing isopropyl myristate emerged as the best delivery system for alpha-T among all the systems studied. Pig skin is a suitable in vitro model for studying the permeation of alpha-T and possibly other antioxidants, though in vivo experiments in humans are required to further corroborate the data.
Ageing skin is characterized by fine lines, wrinkles, lentigines, dyspigmentation and increased coarseness. Topical preparations alleged to combat these changes abound in the over-the-counter market. Some of the most popular ingredients used in these products are vitamins, minerals and botanical extracts. Proposed mechanisms for antiageing effects on skin range from antioxidant properties to improved collagen synthesis or protection from collagen breakdown. Despite the media attention and consumer popularity that these ingredients have generated, there have been few scientific studies to support these claims. In this report, we review recent published studies on the most common of these ingredients for the topical photoprotection and the treatment of ageing skin.
Wrinkles now have a greater social impact because people live longer. Science and hedonism overlap in the search for causes, treatments and prevention of wrinkles.
The cosmetic approach to wrinkles includes:
Active ingredients go well beyond simple moisturisers and exert a more complex activity in protecting skin from external injuries, nourishing it and removing its superficial layers. Transport systems and excipients are increasingly effective. Functional agents currently include alpha hydroxy acids (AHAs), poly-AHAs, complex poly-AHAs, retinoids, fish polysaccharides, anti-enzymatic agents, antioxidants (including ascorbic acid, pycnogenol, ursolic acid, vegetable isoflavones, vitamin E, coenzyme Q10, lipoic acid, resveratorol, l-carnosine and taurine) as well as agaricic acid and various plant extracts. All are reviewed in this text. Most are topical, some can be given by mouth, even as food supplements.
Cosmetics are becoming closer to drugs in preventing and treating wrinkles. Included amongst the cosmeceuticals are the anti-wrinkle agents described herein.
It is already known that the photostability of a sunscreen is important for its performance on human skin. On the other hand, there are many formulations besides sunscreens containing combinations of UV-filters and daily use active substances with other claims like hydration and anti-aging effects. Vitamins A, C and E are frequently added in these kinds of products and it is not known if the UV-filters have some influence on the hydration and anti-aging effects of these vitamins on the skin as well as on their stability mainly when photounstable UV-filters like avobenzone and octyl methoxycinnamate are present in the formulation. Thus, the aim of this study was to evaluate the influence of two different UV-filters combinations, a photostable and a photounstable one, on the photostability as well as on the efficacy of a formulation containing vitamin A, C and E derivatives. The formulations that were investigated contained or not (vehicle: formulation 1) a combination of 0.6 % (w/w) vitamin A palmitate (1,700,000 UI/g), 2 % (w/w) vitamin E acetate and 2% (w/w) ascorbyl tetraisopalmitate (formulation 2) supplemented with a photounstable UV filter combination octyl methoxycinnamate (OMC), avobenzone (AVB) and 4-methylbenzilidene camphor (MBC) (formulation 3) or with a photostable UV filter combination OMC, benzophenone-3 (BP-3) and octocrylene (OC) (formulation 4). In the photostability studies, all formulations were spread onto a glass plate and exposed to UVA/UVB irradiation. The filter components and vitamins were quantified by HPLC analysis with detection at 325 and 235 nm and by spectrophotometry. To simulate the effects of these formulations daily use, all of them (formulations 1-4) were applied on the dorsum of hairless mice, which were submitted to a controlled light-dark cycle (and were not irradiated), once a day for 5 days. Transepidermal water loss (TEWL), water content of the stratum corneum and viscoelastic properties of the skin were analyzed by using different non-invasive Biophysics Techniques in order to evaluate hydration and anti-aging effects of these formulations as well as erythema to assess skin irritation. Histopathology, viable epidermal thickness as well as the number of epidermal cell layers were also evaluated. It was observed that both UV filters combinations (photounstable one containing OMC, AVB and MBC and photostable one containing OMC, BP-3 and OC) enhanced vitamin A photostability and F4 was more photostable than F3, in terms of vitamin A. In vivo efficacy studies showed that F2, F3 and F4 enhanced the viable epidermal thickness, the number of epidermal cell layers, TEWL and Uv/Ue parameter, when compared to the vehicle, which can suggest that they enhanced viable epidermis hydration and acted in cell renewal. However formulation 2 (containing only vitamins), which was the most photounstable formulation, provoked an irritation on hairless mouse skin, and consequently it cannot be considered as safe as the other formulations. It can be concluded that both UV filters combinations did not influence the hydration and anti-aging effects of the formulations containing the vitamins under study and reduced the skin irritation observed when the vitamins were present in the formulation. In addition, the photostable UV-filters combination had the highest recovery of vitamin A in the photostability studies. Finally, it could be suggested that the presence of UV-filters can be considered interesting for the reduction of skin irritation and the most suitable formulation was the one containing the combinations of vitamins A, C and E with photostable UV-filters.
Dithranol as a 0.5% preparation in different vehicles was investigated on healthy volunteers. For comparison Psoradexan® forte containing 0.2% Dithranol and urea were tested. Evaluative parameter for the Dithranol-effect was the measurement of the inflammatory response by laser doppler frequency after 48, 72, and 96 hours. Without exception all preparations lead to an erythema, which could be observed during the leugth of the experiment. The type of vehicle for the application of Dithranol seemedto have only a slight influence on the Dithranol effect. In contrast the type of the vehicle significantly influenced the clinical effect of topical corticosteroids.
Urea affects human skin by penetrating different skin layers. For this a strong vehicle dependence is evident. Therefore, considerable differences could be found in the duration and intensity of increased water-binding capacity after the application of different urea-containing emulsions. For therapy to increase the hydration and water-binding capacity in the horny layer of diseased skin, preparations with 10% urea are better suited than those containing 2% or 5% urea. By altering the functional structure of the horny layer and considerably increasing the drug's liberation from its ointment base, urea is one of the most effective penetration promoters. An increased penetration rate of some corticoids and dithranol from urea-containing ointment were demonstrated in human skin. The resulting penetration promotes two possible applications in topical therapy: an increased therapeutic effect for a given concentration of an active constituent or a given therapeutic effect with a reduced concentration of the active ingredient.