bluuebunny/crossref_metadata_2025 huggingface dataset:
Étude de la stabilité thermique du réseau collagène de la peau par calorimétrie différentielle. Influence d'un traitement cosmétique
Authors: FLANDIN F. , MASMEJEAN M. , Et C. BUFFEVANT , ROMEU M.
Published: May 2007

Afin d'étudier l'influence d'un traitement cosmétique (crème au collagène) au niveau du derme de rats, nous avons utilisé une technique physico‐chimique: la calorimétrie différentielle programmée. Cette méthode renseigne sur la température et l'enthalpie de dénaturation des fibres collagènes du derme.

Nous avons pu mettre en évidence par cette technique un abaissement de plus de 2°C de la température de fin de dénaturation du collagène chez des animaux âgés de 5 mois et ayant subi 4 mois de traitement (entre 1 et 5 mois). En revanche, aucune modification n'est apparue après ce même traitement chez des rats de 9 mois (traités entre 5 et 9 mois).

Par ailleurs, l'étude de l'évolution de ces paramètres thermiques avec l'âge sur des animaux témoins montre que les animaux traités pendant 4 mois par une crème au collagène et âgés de 5 mois possèdent un réseau collagène dont la stabilité thermique étudiée par calorimétrie différentielle est voisine de celle obtenue pour des animaux témoins âgés de 3 mois.

La différence observée pourrait correspondre à des modifications de la structure des fibres collagènes et/ou de la nature et du taux de leurs liaisons de réticulation.

Study of the thermal stability of skin collagen by differential calorimetry. Influence of a cosmetic treatment
A fully automated system to study skin surface patterns
Authors: CORCUFF P. , CHATENAY F. , LEVEQUE J. L.
Published: May 2007

Synopsis

An image analysis method to measure the human skin microrelief has been previously proposed.

This new method has been recently automated, using a ‘robot’electronically driven by a Quantimet 900. This ‘robot’consists of a change‐over specimen driven by four motors, and allows forty Silflo® replicas to be analysed in 6 hours, each analysis giving the main directions of the furrows, their density and their mean depth.

For example, the volar forearm microrelief was studied from the detected shadows created by a 26° angle lighting, in the range of 5 to 100 μm deep furrows. A 38° angle lighting allows such measurements from 50 to 1000μm and is used for studying ‘crow's feet’wrinkles of the face.

Results clearly show that deep wrinkles appear as early as 30 years old on the human face. The consequences of actinic and mechanical stresses over the life span are discussed.

Un système automatique pour l'étude du relief cutané chez l'homme
Stabilisation des émulsions: influence des colloïdes hydrophiles
Authors: SAUNAL H. , ALVARADO D. , Et J. PASSET , DELONCA H.
Published: May 2007

Afin d'améliorer la stabilité des émulsions à base d'huile de paraffine, d'huile d'olive, de Myglyol 812 et de plusieurs couples émulsifiants constitués de tensio‐actifs non‐ioniques, cinq polymères hydrophiles ont été utilisés: la carboxyméthyl cellulose sodique, l'hydroxyéthyl cellulose, l'agar‐agar, une argile hydrophile synthétique et un polymère carboxyvinylique.

Après douze mois de conservation, il ressort un certain nombre de points: parmi les trois huiles utilisées l'émulsion à base d'huile d'olive se révèle être la plus difficile à stabiliser. L'addition d'un hydrocolloïde n'entraîne pas forcément la stabilisation d'une émulsion et parmi les additifs testés c'est le polymère acrylique qui se révèle être le plus efficace.

Stabilisation of emulsions: influence of hydrophilic colloids
Major isomers of the active ingredient of the sunscreen 5(3,3‐dimethyl‐2‐norbornylidene)‐3 pentene‐2‐one
Authors: SAUNAL H. , BEIJERSBERGEN G. M. J. , HENEGOUWEN VAN , DELONCA H.
Published: May 2007

Synopsis

With high‐performance liquid chromatography the three major isomers present in the sunscreen agent, 5(3, 3‐dimethyl‐2‐norbornylidene)‐3 pentene‐2‐one, have been isolated and quantified. Their structures have been determined using mass, infra‐red, and NMR spectrometry.

Isomères dans le filtre solaire 5(3, 3‐dimethyl‐2‐norbornylidene)‐3 pentene‐2‐one
Influence des variations thermiques sur la structure du cheveu
Authors: BORIES M. F. , MARTINI M. C. , Et M. F. BOBIN , COTTE J.
Published: May 2007

Les auteurs ont étudié l'incidence de températures croissantes de 20 à 200°C sur la structure superficielle et profonde du cheveu dans le but de définir une température optimale de séchage permettant de respecter l'intégrité de la fibre de kératine tout en favorisant la permanence de sa déformation.

Pour ce faire, diverses techniques ont été mises en oeuvre: microscopie à balayage, dosage de l'eau par la méthode de Karl Fischer, calorimétrie différentielle et diffraction des rayons X.

Il apparait une température critique de 140°C en deçà de laquelle les modifications observées sont faibles, réversibles et liées à la perte progressive de l'eau libre. Au delà de 140°C, les modifications structurales sont profondes et irréversibles. Elles se traduisent par un changement d'aspect dû au plissement de la cuticule, les écailles de la cuticule disparaissant peu à peu.

Après élimination de l'eau liée, la dégradation totale de la structure interne est obtenue aux environ de 200°C.

On peut toutefois sélectionner une température optimale de séchage de 60°C pour laquelle la fixation ultérieure de l'eau par le cheveu sec sera plus lente le rendant moins sensible aux variations hygrométriques.

Effects of heat treatment on hair structure
Study of the fate of Bronopol and the effects of antioxidants on N‐nitrosamine formation in shampoos and skin creams
Authors: DUNNETT P. C. , TELLING G. M.
Published: May 2007

Synopsis

The role of antioxidants in preventing nitrosamine (N‐nitroso diethanolamine) formation in shampoos and skin creams and the levels of Bronopol (2‐bromo, 2‐nitropropane‐1, 3‐diol) addition in relation to the resultant levels of N‐nitroso compounds have been studied.

The addition of 0.05% BHT, α‐tocopherol or ascorbate was effective in preventing nitrosamine formation (limit of determination: 2.5 μg kg‐1) in products preserved with 0.01% Bronopol. At 0.05% Bronopol, 0.2% of all three antioxidants was effective in preventing nitrosamine formation but at 0.1% Bronopol only α‐tocopherol was effective.

Levels of Bronopol found in shampoo formulations stored for 2 weeks at 37°C with initial concentrations of 0.005‐0.1% were reduced by 64‐86%, independent of the initial concentration. The levels in skin creams stored for extended periods at ambient temperature with 0.01% Bronopol initially were reduced by, on average, 60%.

High nitrite levels (NO2‐) were found in formulations containing 0.01% Bronopol but no antioxidants (200‐250 mg kg‐1). Detected levels of nitrite in skin cream formulations were greater than could be formed by stoichiometric decomposition of Bronopol. In formulations with both Bronopol and antioxidants the levels of nitrite were considerably reduced. When α‐tocopherol rather than BHT or ascorbate was the antioxidant then the nitrite levels were appreciably higher but formation of N‐nitroso diethanolamine was no greater.

High nitrite levels correlated with the formation of detectable levels of N‐nitroso compounds in the absence of antioxidants.

Le rôle préventif du Bronopol et des antioxygènes dans la formation de la nitrosamine
Fatty acid sulphoalkyl amides and esters as cosmetic surfactants
Authors: PETTER P. J.
Published: May 2007

Synopsis

A review is given of the manufacture, properties and applications of the anionic surfactants commonly known as taurates and isethionates (fatty acid sulphoalkyl amides and esters, respectively). Originally developed in the 1930s for textile processing, these surfactants are used increasingly in the cosmetic field, particularly those derived from coconut fatty acid.

Both types are produced from sodium isethionate, HO°C2H4SO3Na. The acyl isethionate, R°COO°C2H4SO3Na, is obtained by reaction with a fatty acid (‘direct process’). or fatty acid chloride (‘indirect process’). The direct process is cheaper but requires extreme conditions which can lead to discoloration of the product and a loss of shorter chain fatty acid components.

The N‐methyl‐N‐acyltaurate, R°CON(R1)C2H4SO3Na, is obtained by Schotten‐Baumann reaction of a fatty acid chloride with N‐methyltaurine, which is derived from sodium isethionate via methylamine.

Taurates and isethionates retain the benefits of the soaps to which they are structurally similar, but chemical modifications have eliminated many undesirable features. Thus they combine good detergency and wetting with high foaming, and maintain their performance in hard or salt water. Taurates are stable to hydrolysis over the whole pH range. Isethionates are prone to hydrolysis at high (>8) or low (<5) pH, but this does not normally present a problem in cosmetic formulations.

Above all, these surfactants are characterized by their extreme mildness to skin. Syndet and syndet/soap bars based on isethionate can be formulated at neutral pH (‘Dove type’bars) instead of the alkaline pH of soap, and have been shown in various studies to be milder than soap and better tolerated by the young, the old and those with sensitive skins. Similarly, isethionates have been shown to be less irritating than other anionic or amphoteric surfactants used in cosmetics. The difference has been related to the negligible effect of isethionate on the water‐binding capacity of stratum corneum.

Other cosmetic applications besides toilet bars include shampoos (excellent cleaning, mild to scalp, some hair conditioning effects), liquid soaps (mild for all‐over body use), bubble baths (copious stable foam, efficient lime soap dispersal, low irritancy), skin creams and lotions (emulsification, alleviation of ‘dry skin’), baby care products (ultra‐mild cleansing bars and milks, impregnated baby wipes) and oral products (foaming agents with low toxicity for toothpastes and mouthwashes).
Prediction and measurement of surfactant action upon human skin under realistic conditions
Authors: PROTTEY C. , OLIVER D. , COXON A. C.
Published: May 2007

Synopsis

The lysosomal enzyme acid phosphatase has been characterized and quantified in tapestrip biopsies of human stratum corneum by means of a sensitive spectrofluorometric procedure. When the stratum corneum of panellists was exposed to dilute solutions of various surfactants under realistic exposure conditions, the changes observed in stratum corneum acid phosphatase specific activity have been found to correlate very closely with the visual, macroscopic changes such as dryness and flakiness, that are elicited in skin as a result of surfactants. This method monitors denaturation of stratum corneum proteins, which is an important feature of skin surfactant interactions, and serves as an effective, non‐invasive predictive tool for skin irritancy and mildness of surfactants.

Prevention et mesure de l'action des tensio‐actifs sur la peau humaine dans des conditions conformes a la réalité
Analysis of hexamidine, dibromohexamidine, dibromopropamidine and chlorhexidine in cosmetic products by high‐performance liquid chromatography
Authors: BUKANSKI B. WYHOWSKI DE , MASSE M.O.
Published: May 2007

Synopsis

A method of determining qualitatively and quantitatively hexamidine, dibromohexamidine, dibromopropamidine and chlorhexidine in cosmetic products by means of paired ion, reverse‐phase high‐performance liquid chromatography (HPLC) and ultraviolet detection (UV) at 264 nm.

Détermination de l'hexamidine, du dibromohexamidine, du dibromopropamidine et de la chlorhexidine dans les produits cosmétiques
Interpretation of predictive data on safety‐in‐use of toiletry products
Authors: EBBÉ N. J. VAN
Published: May 2007

Synopsis

Toiletries are the subgroup of cosmetics mainly used for cleansing and personal hygiene of the skin, the hair or the dentition. Some of these preparations may be considered also to have medicinal characteristics and are liable to be placed in a ‘borderline’category which may have regulatory implications.

Predictive safety testing is designed to ensure as far as possible that new toiletries may be used without harm to health. Attention to the severity of adverse effects rather than their numerical incidence is necessary when assessing risks associated with toiletry use. Benefits derived from using toiletries are primarily concerned with personal hygiene and grooming, to give increased self‐assurance and social acceptance. The relationship between benefit and risk is not easily described in mathematical terms, mainly because benefits from using toiletries are hard to quantify. However, other ways of studying risk in relation to benefit may be considered.

Évaluation des risques du produits d'hygiène corporelle
Colour extension properties of individual pigments and effects on shades of foundations in cake form
Authors: TSUGITA AKIRA , FUKISHIMA TAKASHI , YONEYA TOHRU , INISHIJIMA YASUSH
Published: May 2007

Synopsis

The mechanism of colour change during the pigment dispersion process and during powder application to the skin surface was studied by examining the colour extension properties of Yellow. Red, and Black iron oxides in white powder bases. A new measure for the evaluation of the degree of colour extension was devised. This measure corresponded well with human visual sensation, and was found to be useful for comparing the rates of colour extension of pigments. The rate of colour extension of pigments was found to vary in the order: Yellowacicular Redgranular RedBlack. This result explains colour darkening and the change towards reddish tones during the pigment dispersion process, because Yellow extends fully in the early stage of the process but Red, especially in granular form, and Black continue to extend even in the later stage. Acicular Red iron oxide is more favourably employed than the granular form to attain sufficient colour extension of foundations with lower energy expenditure, and to decrease the discrepancy between the cake colour and the colour of applied powder.

Le développement des oxydes de fer et effet sur les nuances des fonds de teint compacts
Activité et modalités d'action de la sébathionine (D.C.I.) sur la séborrhée
Authors: OUSTRIN JEAN , ROMECKI ALAIN
Published: May 2007

L'activité antiséborrhéique de la sébathionine a étéétudiée sur la glande costovertébrale de hamster mâle castré et supplémenté en testostérone. Le test utilisé est l'incorporation de précurseurs marqués de la synthése lipidique.

Le glucose comme l'acétate de sodium voient leur vitesse d'incorporation diminuer sous l'influence de la sébathionine. L'emploi d'un faux précurseur: le déoxyglucose montre que le produit agit de façon non spécifique sur la synthése lipidique.

Cependant, au niveau de la synthése des acides gras, on peut préciser que l'action se situe au niveau des mécanismes d'allongement des chaines carbonées et non au niveau des processus de désaturation.

Activity and mechanism of sebathionine (D.C.I.) on sebum formation
An in vivo assessment of the biomechanical properties of human skin modifications under the influence of cosmetic products
Authors: AUBERT L. , ANTHOINE P. , RIGAL J. DE , LEVEQUE J. L.
Published: May 2007

Synopsis

A new device using a torsional technique has been developed to record the biomechanical properties of the skin.

After determination of the optimal experimental conditions, effects of cosmetic products on the stratum corneum biomechanical properties are described.
Topical and bioavailability of benzoyl peroxide
Authors: SAHUT A. , AIACHE S. , ANDERMANN G. , BURLET G. DG , AIACHE J.‐M.
Published: May 2007

Synopsis

Benzoyl peroxide has been used for over 20 years to treat youthful acne. The aim of this study is to determine its release rate from the vehicle that allows it to reach and treat the skin (topical availability) and its ability to pass through the skin and reach the general circulation (bioavailability), in order to bring about good topical availability, linked to bioavailability or, an ‘abioavailability'.

Three preparations containing 10% of benzoyl peroxide were administered to the back of shaven New Zealand rabbits. At day 0, day 5, day 12, day 19, day 26 and day 33, the topical effects were measured by cutaneous temperature, degree of erythema and the benzoic acid plasma record card, which shows blood sample results of the metabolism of the drug.

The results obtained show that the topical availability of benzoyl peroxide coincides with a decrease in cutaneous temperature, after application in various dosage forms, in spite of the appearance of a marked erythema.

The bioavailability is demonstrated by plasma benzoic acid evaluation. Before administration, benzoic acid levels are low but increase half an hour after administration, to reach a maximal level at 3 h.

Benzoyl peroxide metabolizes quickly and does not seem to be able to cross the skin without being changed.

Disponibilité topique et biodisponibilité du péroxyde de benzoyl*
Substantivity to hair and skin of 125l‐labelled collagen hydrolysates under application simulating conditions
Authors: TUROWSKI A. , ADELMANN‐GRILL B. C.
Published: May 2007

Synopsis

Substantivity of various 125I‐labelled collagen hydrolysates to virgin or bleached and dyed European hair or human callus was tested under conditions which simulated actual application of such hydrolysates in shampoos or foam baths. Factors which most strongly influence protein substantivity were identified. The molecular properties of the hydrolysate are the most important factor. The hydrolysate which adsorbed best had the lowest overall isoelectric point, the highest pH in solution and the largest content of high molecular weight peptides. The extent of adsorption was also a function of concentration of protein, of the duration of application and of the nature of the components of the formulation. Thus, the combination of shampoo and hydrolysate can be adjusted so that a desired substantivity is attained.
Absorption of materials by or through the living skin
Authors: HADGRAFT J.
Published: May 2007

Synopsis

The skin comes into contact with a large range of materials either deliberately or inadvertently. It should be possible to predict the exact transport rates of these materials through the skin as a function of the physicochemical properties of the different compounds. With this sort of knowledge it is possible to predict the exact disposition of compounds and use this in the formulation of new products both in the pharmaceutical and cosmetic field. The information will also be useful from the standpoint of skin toxicology and environmental health. In order to be able to predict this complex process it is necessary to split the overall transport into different component parts. This article will identify these components and provide illustrations. The major areas discussed will be barrier function of the skin, the release properties of different topical formulations and how these may be monitored. Novel means of enhancing the penetration of drugs will be discussed and how some additives that are incorporated into formulations will perhaps alter the barrier function of skin. A mathematical model describing skin penetration has been developed and its use in predicting blood levels will be described. This model has been tested both in animal experiments and in limited human studies and its relevance to these situations will be highlighted.

Absorption cutanée et transcutanée in vivo
Evaluation of anti‐wrinkle effects on humans
Authors: CORCUFF P. , CHATENAY F. , BRUN A.
Published: May 2007

Synopsis

Image analysis provides a practical method for studying the cutaneous relief and better understanding of the formation of wrinkles during ageing and their regression induced by an anti‐wrinkle product. Quantimet 900° allows a fully automated analysis of 40 replicas of skin surface per cycle of 6 h. The basic principle consists of measuring shadows, generated by incident lighting at the surface of Silflo replicas. Incident light of 38° was selected for analysing crow's feet wrinkles and 26° for the microrelief when crow's feet were absent (slight furrows less than 50 μ‐m). The following parameters were recorded: the number of wrinkles, their mean depth, and the coefficient of developed skin surface (CDSS).

An O/W emulsion containing 30% biological ingredients was applied daily on the face of 140 female subjects, aged from 20 to 57 years, during 4 weeks. Replicas were made before the first application (t0) and 24 h after the last one (t0). Data obtained with the image analysis method showed a decrease in number and depth of crow's feet from t0, to t4 of 16% and a sharp decrease of the CDSS (30%). No modification of the microrelief was observed. These results were confirmed by measuring forehead casts with the Anaglyphographc® apparatus (a profilometric method) on the same subjects: a decrease of 40% in number and 23% in depth were recorded for the forehead wrinkles, with no modification of the microrelief.

Both image analysis and profilometry measured the effects provoked by this treatment. The CDSS, which might measure the reservoir of extensibility of the surface of the skin, should be the best parameter to demonstrate the efficiency of anti‐wrinkle products.

Evaluation des effets anti‐rides chez I'homme
Use of microemulsions as vehicles for nucleophilic reagents in cosmetic formulations
Authors: PARRA J. L. , GARCÍA DOMÍNGUEZ J. J. , COMELLES F. , SÄNCHEZ J. , SOLANS C. , PELEJERO C. , BALAGUER F.
Published: May 2007

Synopsis

The modifications of chemical reactivity induced in the human hair during its treatment with oxidative (H2O2) or reductive (HSO3Na) agents via a micellar or a microemulsion system have been investigated. For this purpose, phase diagrams of micellar solutions and microcmulsions with H2O2 or NaSO3H have been made in order to find out the corresponding areas of solubility. The properties of conductivity, surface tension and light scattering of various monophasic compositions as a function of their water content, have been studied.

As a result of the chemical reactivity data of human hair obtained through the reaction of H2O2 or HSO3Na via a micellar or a microemulsion system, it appears reasonable to predict a more effective reaction of such agents with cystine residues existing in keratinic substrates, particularly when they are applied via a microemulsion. The decrease of the water content of the compositions considered, increases chemical reactivity of the keratinic proteins favouring the formation of cysteine and of cysteic acid in the reductive or oxidative treatments respectively.
The dissolution rate of zinc pyrithione
Authors: DAVIES T. W.
Published: May 2007

Synopsis

A method of measuring and correlating the rate at which zinc pyrithione dissolves during a shampoo is described. The rise in zinc concentration of a solution in a stirred vessel following the introduction of a dose of zine pyrithione suspension was measured as a function of time using atomic absorption spectrophotometry. An analysis of the mass transfer processes occurring during the dissolution of a suspended solid in a stirred vessel was used to correlate the concentration‐time measurements. The analysis allows a calculation of the characteristic solution time, the mass transfer coefficient and the diffusion coefficient for the system. In this way the effect of changing shampoo formulation can be systematically studied.

Le taux de dissolution de zinc pyrithione.
Photostability of Cosmetic Materials
Authors: SUGDEN J. K.
Published: May 2007

Synopsis

The basic principles of photochemistry and photochemical reactions applicable to the topic are briefly reviewed. A more detailed survey of the photochemical reactions of raw materials used in the formulation of cosmetics is treated, according to the principal chemical classification of the material. In each group the photochemical reactions of the substance are reported with the more apparent implications for the cosmetic industry highlighted. The effects of photochemical catalysts are discussed, including the sources of impurities which can catalyse photochemical spoilage of cosmetic products. The methods of retarding photochemical degradation are appraised, including precautions which could be adopted in manufacturing processes and the use of additives collectively known as antioxidants.

La stabilite a la lumiere des produits cosmetiques
Application of emulsion theory to complex and real systems
Authors: ECCLESTON G. M. , FLORENCE A. T.
Published: May 2007

Synopsis

Theories of emulsion stability are discussed in relation to dilute, concentrated and semisolid emulsions. It is shown that whilst a unified theory cannot be applied quantitatively to emulsion systems, a better understanding of the various mechanisms of stabilization and breakdown is emerging. Established concepts, eg, the HLB concept, are now given a less empirical gloss.

The application of colloid stability theory, even to very dilute emulsions, is difficult. This is because of the polydispersity of the systems and because surfactant and stabilizers may be free to move on the globule surfaces, as well as dissolve in the dispersed or continuous phases. Further difficulties arise because flocculation is not necessarily a sign of emulsion instability in the practical sense, as creamed or flocculated emulsions often may be redispersed by shaking. Crucial to emulsion stability is the prevention of coalescence, and this is governed by the nature of the adsorbed emulsifier film.

The flocculation and coalescence that can be understood in dilute emulsions from the DVLO theory and the metastability of thin films against rupture do not address themselves to flocculation and coalescence in concentrated, structured or semi‐solid emulsions. These may possess surfactant multilayers rather than monolayers at the oil/water interfaces and the bulk phases are frequently structured. Some emulsions invert at critical temperatures. In semi‐solid emulsions, stability is controlled by the phase behaviour of the emulsifier components, rather than by the forces governing stability in dilute colloids and thin films. Stability is usually considered to be product stability during storage. The stability of an emulsion in use, eg, during and after application to the skin, is a topic of equal importance but little documented. This related problem is also discussed.

Application de la theorie des emulsions aux systemes complexes et reels

On discute les théories de la stabilité des émsions diluées. concentrées et semi solides. Bien qu'une théorie unique ne puisse s'appliquer de façon quantitative á tous les systemes d'emulsions, il ne s'en dégage pas moins une meilleure compréhension des mécanismes de stabilisation et de rupture. Les concepts établis, tels que la valeur HLB apparaîssent maintenant moins empirique.

L'application de la théorie de la stabilité des colloïdes est difficile même pour les émulsions diluées. Cela est dûá la diversité des systèmes et au fait que les surfactifs et les agents de stabilisation sont libres de se mouvoir sur la surface des globules comme de se dissoudre dans les phases dispersée et continue.

Des difficultés supplémentaires surviennent du fait que la floculation n'est pas obligatoirement synonyme de l'instabilité de l'émulsion et que des émulsions eremeuses ou floculées peuvent souvent être redispersées par agitation. Le paramétre important pour la stabilité des émulsions est la prévention de la coalescence ce qui est liéà la nature du film d'émulsif adsorbé.
Sun protection factors
Authors: STOCKDALE M.
Published: May 2007

Synopsis

The absorption of ultraviolet light by a film of sunscreen product on the surface of the skin is considered from a theoretical standpoint. It is apparent that Beer‐Lambert's Law would predict protection factors in excess of the actual factors by many orders of magnitude. The possible reasons for this are discussed in detail, and the relevance of it to in vitro and in vivo measurements of protection factors, and also the in‐use situation, are discussed. The implications for formulators of sunscreen products are also discussed.

The methods of measuring protection factors are reviewed. These include instrumental methods, based on both solutions and thin films, model systems, animal methods and human volunteer studies. The current situation with respect to proposed standard methods for measuring sun protection factors, particularly the American FDA method and the German DIN method, is reviewed.
Percutaneous absorption of urea
Authors: ACKERMANN CHRISITA , FLYNN GORDON L. , WYK CHRIS J. VAN
Published: May 2007

Synopsis

The effect of several variables on the in vitro permeation of urea through hairless mouse skin has been studied in order to determine the causes of an increasing permeability phenomenon found in studies with a range of hydrophilic compounds.

The permeation of urea increased for a period of approximately 100 h after which a steady state permeation pattern was observed for approximately 25 h. Urea did not effect its own permeation in concentrations between 0.01 M and 1.67 M, and the same pattern of increasing permeation was followed in the presence of (N‐morpholine)propanesulphonic acid and tris(hydroxyme)amino‐methane buffers, as in the presence of normal saline. Urea did not affect the permeation of tritiated water. Methanol and water exhibited the same pattern of increasing permeation as urea.

The continuously increasing permeation rate of urea up to 100 h is believed to be due to penetration and extensive association of water with the components of the stratum corneum, altering the ultra‐structure of the stratum corneum and leading to the formation of large and extensive hydrophilic diffusion channels which do not exist in fresh, untreated skin. These presumed channels open the stratum corneum to facile permeation of highly polar substances such as urea. The physical events leading up to the ultra structural changes within the tissue at the microscopic level remain obscure and are the subject of ongoing research.

L'absorption percutanée de l'urée
Mutagenicity evaluation of nitroanilines and nitroaminophenols in Salmonella typhimurium
Authors: SHAHIN MAJDI M.
Published: May 2007

Synopsis

In our studies of structure‐activity relationships, three nitroanilines and nine nitroaminophenols were tested for their ability to induce mutations in Salmonella typhimurium strains TA1535, TA100, TA1537, TA1538 and TA98. The compounds m‐nitroaniline, 4‐nitro‐2‐aminophenol, and 3‐nitro‐6‐aminophenol were active in two or more of these strains. The compounds o‐nitroaniline, 2‐nitro‐3‐aminophenol, 3‐nitro‐4‐aminophenol, 4‐nitro‐3‐aminophenol, 3‐nitro‐2‐aminophenol, 2‐nitro‐6‐aminophenol, 2‐nitro‐4‐aminophenol and 2‐nitro‐5‐aminophenol were inactive, both in the presence and in the absence of S9 mix. The compound p‐nitroaniline was also inactive in all tests with the possible exception of that in strain TA98 in the presence of S9 mix, where it was either very weakly mutagenic or non‐mutagenic. The mutagenic activity or inactivity of these compounds appears to be dependent on the positions of the amino, nitro, and hydroxy groups in their chemical structures.

Etude en mutagénèse des nitroanilines et nitroaminophénols sur Salmonella typhimurium.
Fundamentals of stability testing
Authors: CANNELL JOHN S.
Published: May 2007

Synopsis

The principles on which stability tests are based are reviewed. The need to differentiate between product stability and product‐container compatibility is emphasized. Recognition of this distinction is fundamental to the efficient organisation and execution of stability tests.

Attention is also drawn to the desirability of having for every product a release specification with which it must comply when manufactured and a broader check specification with which it must comply throughout its shelf‐life.

Test methods and the interpretation of the data accrued throughout a test are also discussed.

It is concluded that stability tests should not be conducted in accordance with a standardized routine pattern but that the objectives of each test should be defined and the test designed to achieve those objectives in the most efficient way.

Les regles fondamentales des essais de stabilite
The stumptailed macaque as a model for baldness: effects of minoxidil
Authors: UNO HIDEO
Published: May 2007

Synopsis

Topical application of minoxidil in bald scalps of stumptailed macaques successfully induced regrowth of terminal hairs. The rate and degree of hair growth by minoxidil are much greater in the early stage of baldness in adolescent and young adults. Minoxidil also prevented the development of baldness when applied on non‐bald scalps of peri‐adolescent animals. Morphometric analysis of hair follicles (folliculograms) has brought a new aspect in observing cyclic dynamics and growth (transformation) of hair follicles. Using this analytic method and autoradiographic observation of DNA synthesis of hair follicles, the action of minoxidil appears to be a potent mitotic stimulator of the follicular as well as peri‐follicular germinal (or reserve) cells, thus inducing an enlargement of vellus follicles through the process of cyclic growth and maintaining anagen follicles in the growing phases. Most importantly, minoxidil has no influence in epidermal keratinocytes, sebaceous glands and other dermal components. During almost 3 years of consecutive treatment, the animals showed no detectable local or systemic side effects when examined by laboratory tests of blood cells, chemistry, steroid hormones, measurement of blood pressure and EKG test.

Le macaque a queue courte: exemple de calvitie
Distribution and dissociation of benzoyl peroxide in cutaneous tissue after application on skin in the hairless rat
Authors: WEPIERRE J. , CORROLLER M. , DIDRY J. R.
Published: May 2007

Synopsis

The distribution and dissociation of 14C‐benzoyl‐peroxide were studied in the skin of hairless rats after the application of a 10% gel during 3, 8 and 24 h. The distribution was appraised in the stripped horny layer and in the epidermis, and the dermis cut in slices parallel to the cutaneous surface. The conversion of benzoyl peroxide (b.p.) to benzoic acid (b.a.) was investigated from extracts of these different cutaneous layers by thin layer chromatography (TLC). The greatest amount of penetrating b.p. (9 to 14% of the applied dose) was found in the horny layer, which forms a reservoir and where biotransformations were reduced. Small quantities of b.p. diffused toward the epidermis down to the deeper dermis, where b.a. represented 74% of the radioactivity. Distribution gradients of the radioactivity and conversion rates to b.a. were stable between 3 and 24 h of application in all parts of the skin. This result showed that diffusion of b.p. from the vehicle was in balance with the dissociation processes and the blood resorption as b.a., throughout the experiment.

Distribution et dissociation du peroxyde de benzoyle dans le tissu cutané aprés applicationsur la peau chez le rat sans poils
A study of correlations between the release of drugs from petrolatum‐based gels containing nonionic surfactants and some physical and physico‐chemical characteristics of the gel systems
Authors: COLO G. DI , NANNIPIERI E. , SERAFINI M. F. , VITALE D.
Published: May 2007

Synopsis

The in vitro release of benzocaine and 2‐ethyIhexyl p‐di‐methylaminobenzoate (EH‐PABA) from petrolatum‐based gels either containing two nonionic surfactants, or not, was compared with some physical and/or physico‐chemical characteristics of the drugs, the gels and the drug‐gel systems. The surfactants had no effect on the release of EH‐PABA, the less polar drug, whereas they decreased the release of benzocaine. Moreover, the release data show a complex dependence of diffusive properties of ben‐zocaine on drug and surfactant concentration. Benzocaine appears to form mixed micelles with each of the two surfactants and/or undergoes self‐aggregation phenomena within surfactant micelles. The results indicate that drug diffusion is influenced by gel porosity, drug molecular size and polarity and molecular interactions.

Ětude des corrélations entre la disponibilité des medicaments dans les gels a base de vaseline contenant des surfactifs non ioniques et quelques propriétés physiques et physicochimiques des gels
The role of sebum and epidermal lipids in the cosmetic properties of skin
Authors: DOWNING DONALD T. , WERTZ PHILIP W. , STEWART MARY ELLEN
Published: May 2007

Synopsis

Lipids found in the skin are derived both from the keratinized epidermis and from the sebaceous glands. The composition of human sebum and epidermal lipids has only been fully elucidated during the past few years, and the role of these lipids is still being evaluated. This presentation reviews sebaceous gland structure and function composition of human sebum, the effects of aging and hormones on sebum secretion and the role of sebum in acne and in dry skin. In addition, a review of the role of epidermal lipids in the properties of skin includes consideration of the structure and function of the epidermis, the composition of the epidermal lipids, and the function of lipids in epidermal differentia‐tion and water barrier properties.

Le rǒle du sébum et des lipides de I'épiderme dans les propriétes cosmétiques de la peau
Transformation of steroids by axillary coryneform bacteria
Authors: GOWER D. B. , NIXON A. , JACKMAN P. J. H. , MALLETT A. I.
Published: May 2007

Synopsis

The contribution made by the apocrine glands to body odour has been discussed. In particular, the role of odorous steroids, such as 5α‐androst‐16‐en‐3‐one (5α‐A), and their formation by axillary bacteria, has been explored. Isotopically labelled testosterone was incubated (21 days at 37°C) with strains of axillary bacteria, both separately and in mixtures, and the products characterized by capillary gas chromatography (GC) and GC‐mass spectrometry. In many cases testosterone was converted into large yields of 5β‐dihydrotestosterone and 4‐androstenedione, although 5α‐dihydrotestosterone, 5β‐androstanedione and androstanediols were also produced. Mixing certain coryneform bacteria appeared to cause some additive and some inhibitory effects. A non‐polar steroid, with polarity similar to that of 5α‐A, was formed in some incubations, but identification could not be confirmed. Nevertheless, preliminary experiments have indicated that 5α‐A is present in axillary hair of men, and the possible reasons why we have failed to prove the biosynthesis of this odorous steroid are discussed.

La transformation des steroïdes par la bactérie coryneforme des aisselles

L'article traite du rǒle des glandes apocrines dans l'odeur corporelle et de la composition des sécrétions apocrines en particulier des 16‐androstènes. Deux de ces stéroïdes, le 5α‐androst‐16‐en‐3‐one (5α‐androsténone) et le 5α‐androst‐16‐en‐3α‐ol provoquent des phénomènes phéromonaux sur le porc et vraisemblalbment sur l'homme. Etant donné que l'odeur axillaire caractéristique est liée à la présence de bactéries coryneformes, et qu'elle peut ětre combattue par des agents anti bactériens, nous avons tenté d'identifier l'origine de la 5 androstenone malodorante qui est peut ětre également le résultat de l'activité bactériènne.

Pour cela la testoterone marquée avec un isotope radioactif a été incubée pendant 21 jours à 37°C en présence de bactéries coryneformes prélevées sur la peau et les poils des aisselles de l'homme. La testosterone non marquée et la langes de bactéris coryneformes ont été incubées en presence de testostérone marquée, le profil des métabolites obtenus deffére de celui qui résulte de bactérics parises individuellement. On a observé des effects tantčot additifs, tantčot inhibiteurs. Cela indique que la situation in‐vivo est d'une grande complexité car quelque 350 souches différcntcs dc bactéries coryneformes peuvent étre impliquées.

Dans des expériences précédentes nous avons montré que la 5γ‐androstenone est présents sur les poils de lapos;aisselle de l'homme, mais n' avons pas pour autant réussi à montrer la biosynthése dc cc stéroïde. Parmi les raisons possibles 'a cel'a il y a la néessité d'un substrat stéroïde de remplacement et un micro milicu aérophile ou anaérobie.
The effectiveness of cosmetic products in alleviating a range of skin dryness conditions as determined by clinical and instrumental techniques
Authors: PRALL J. K. , THEILER R. F. , BOWSER P. A. , WALSH M.
Published: May 2007

Synopsis

A vast array of cosmetic products are used routinely by consumers to alleviate a range of skin care problems. Consumer concern ranges from age‐associated skin changes to complexion (e.g., spots and pimples) and dryness. However, a major cause for concern amongst European female consumers is skin dryness, which spans all age ranges and skin types. Utilizing instrumental procedures (Squametry and Image Analysis) the severity of skin dryness has been correlated with expert assessment and consumer perception of dryness. The sensitivity of these techniques enables one to follow the progression of dryness alleviation for a range of product forms (e.g., creams and lotions) as well as the purported mechanism of action of various ingredient systems (e.g., occlusivity, moisturization). While conventional cosmetic products are shown to be effective, these techniques can be used to aid in the assessment and formulation of more effective products.

Efficacité des produit cosmétiques à l'allégement d'un spectre d'états de peau sèche selon des measures cliniques et au moyen d'instruments
Oestrogen identification and dosage in filatov human placenta extracts by high performance liquid chromatography
Authors: BEYSSAC I. , MARTINI M. C. , COTTE J.
Published: May 2007

Synopsis

Using high performance liquid chromatography the presence of natural oestrogen traces in aqueous placenta extracts of human origin has been demonstrated. This study, corroborated by results obtained by colorimetric dosage and by gaseous phase chromatography, reveals the preponderance of oestriol, which represents 80% of all the oestrogens.

In all the extracts studied, oestriol concentration was not more than 100° per litre of extract. This quantity of oestrogen contained in human placenta extracts of the Filatov type, even in wide cutaneous applications, cannot influence the subject's hormonal balance.
The use of transepidermal water loss to measure and predict the irritation response to surfactants
Authors: MURAHATA RICHARD I. , CROWE DANIEL M. , ROHEIM JOHN R.
Published: May 2007

Synopsis

The ability of baseline transepidermal water loss (TEWL) measurements to predict the response of healthy subjects to a standard soap chamber irritation insult was evaluated. Chambers containing surfactant solutions were applied to the forearms of normal volunteers for five consecutive days. TEWL was measured using a Servo Med Evaporimeter. TEWL measurements were made prior to the first application of the chambers and following the removal of the second set of chambers (the afternoon of Day 1). The correlation between the TEWL values obtained on Day 1 and the subjective evaluation of irritation resulting from the application of two different toilet soaps was statistically significant. This result indicates that damage to the skin is reflected by an increase in TEWL. Interestingly, there was also a statistically significant correlation between TEWL values obtained on the untreated skin at Time 0 and the five‐day average irritation score for these two cleansing products. The results of this study indicate that a high baseline TEWL value may be predictive of a high susceptibility to soap irritation as measured by the chamber test.

Le role des pertes en eau transepidermique pour mesurer et prevoir l'irritation due aux tensio‐actifs
Transparent oil‐water gels
Authors: PROVOST C.
Published: May 2007

Synopsis

The present article reviews both the cosmetic and the pharmaceutical literature concerning transparent oil‐water gels. We propose the term ‘transparent oil‐water gel’ for semisolid systems that consist mainly of water, oil and an emulsifying agent or agents and that are characterized by a jelly‐like consistency, transparency, homogeneity, optical isotropy, thermodynamic stability, and the occurrence of a ‘ring’ or resonance when a containerful is tapped. The literature reflects a rather remarkable degree of confusion, not only with regard to terminology, but also with regard to the basic concept of the formation of transparent oil‐water gels. After a brief discussion justifying our selection of the term, the advantages specifically attributed to these gels are summarized, and the raw materials used in their formation as well as factors affecting their formulation are described. Finally, their applications as cosmetic and as pharmaceutical vehicles are reviewed.
Hand cleansing and skin condition. A comparison of conventional soap washing and the use of alcohol‐impregnated paper cloths
Authors: PROTTEY C. , PRYCE N. G.
Published: May 2007

Synopsis

By means of a controlled hand‐cleansing trial on normal volunteers with no observable skin problems, we have compared the action of a high frequency of washing the hands with soap and water with the use of alcohol‐impregnated paper towels, using visual assessment of hand dryness by a trained operator as the criterion of skin condition. High frequency of soap‐and‐water washing (10 times daily) elicits a significantly higher level of hand dryness than a frequency of 1–2 times daily. This effect, although transient, indicates a gradual build‐up of a higher prevailing level of hand dryness with sustained higher frequency washing. Use of the alcohol‐impregnated towels even at this higher frequency of 10 times per day does not elicit the observed level of hand dryness seen with soap washing.

Le lavage des mains et de la peau. Une comparaison entre le lavage traditionnel des mains avec du savon et I'usage de serviettes imprégnées d'alcool

L'action d'un nombre répété de lavages des mains utilisant du savon et de I'eau comparée à l'utilisation de serviettes imprégnées d'alcool. A étéétudiée sur des volontaires ne présentant pas de problèmes particuliers de peau, I'examen de la peau et en particulier de son déssèchement étant effectué par un spécialiste forméà cet effet.

Un usage répété de savon et d'eau (10 lavages quotidiens) provoque un déssèchement de la peau significativement plus élevé qu'une fréquence de un à deux lavages par jour. Cet effet, bien que temporaire, indique une accumulation graduelle d'un niveau élevé de déssèchement de la peau liée à une fréquence élevée et soutenue de lavages. L'utilisation de serviettes imprégnées d'alcool měme à cette fréquence d'utilisation de 10 usages quotidiens, ne provoque pas un désséchement des mains au niveau observé lors des lavages avec eau et savon.
Microbial degradation of cellulose polymers used in cosmetics and toiletries
Authors: HARRISON L. A.
Published: May 2007

Synopsis

Cellulose polymers which are commonly found in cosmetics can act as potential targets for microbial attack and sometimes support extensive growth under suitable conditions. As a result, cellulosic substances can be converted from a stiff gel into a running liquid, thereby rendering the cosmetic unfit for use.

To provide an understanding of the biodeterioration of cellulose in cosmetics, this paper reviews the structure of cellulose, mechanism of enzyme degradation and effects of structural properties of cellulose on the rate of hydrolysis. At least three different types of enzymes (exo‐β‐1, 4‐glucanase, endo‐β‐1,4‐glucanase and β‐glucosidase) are involved in the degradation of crystalline cellulose. Enzyme production by three fungi belonging to the genera Aspergillus, Fusarium and Penicillium is described.

Dégradation microbienne des polymers de cellulose utilisés dans les produits cosmétiques et de toilette