bluuebunny/crossref_metadata_2025 huggingface dataset:
Histamine determination in tears as an index of safety in use of cosmetic products
Authors: BETTERO A. , ANGI M. R. , GALIANO F. , BENASSI C. A.
Published: May 2007

Synopsis

To assess ocular irritancy caused by chemical and cosmetic products a reliable method based on evaluation of histamine (Hm) in tears is presented. Hm is measured at picomole levels by HPLC and fluorimetric detection after fluorescamine‐HM derivatization. In order to avoid any uncontrolled irritation and stimulation of the conjunctiva during sample collection, a procedure of conjunctiva lavage was developed. A balanced salt solution (50 μl) containing a known amount of Hm‐fluorophore as reference standard is instilled in the conjunctiva fornix. After a few seconds 20 μl of tear fluid is collected: 10 μl are immediately analysed and 10 μl after derivatization reaction. In this way it is possible to evaluate tear dilution and to assess Hm content in less than 10 minutes.

In a group of 20 normal subjects Hm has been determined in comparison with that of two volunteers after topical application of 50 μ of 0.2% and 0.4% sodium lauryl sulphate solution. A contact of 30 seconds of the cosmetic ingredient caused an immediate dose‐dependent Hm release through a direct cytotoxic damage of cell membranes due to the surfactant action.

Évaluation de l'irritation occulaire due aux cosmétiques par la détermination de l'histamine lacrimale
Antibacterial properties of soap containing some fatty acid esters
Authors: PANDEY N. K. , NATRAJ C. V. , KALLE G. P. , NAMBUDIRY M. E. N.
Published: May 2007

Synopsis

Chemical microbial inhibitors compatible with formulations of soaps and deodorant perfumes are more effective if they are substantive to the skin. However, highly effective inhibitors are toxic and their substantivity on skin may accentuate the toxicity. Natural compounds such as short to medium chain fatty acids and their derivatives, which are known to be germicidal, offer a viable alternative to chemical inhibitors. We report here the synthesis of sodium 2‐lauroyloxy propionate and an in vivo method to test its substantivity on skin following its incorporation in soaps. Among several compounds tested, sodium 2‐lauroyloxy propionate was found to be highly substantive in soap formulation.

Propriétés antibactériennes d'un savon contenant des esters d'acides gras
Physical attractiveness, cosmetic use and self‐perception in the elderly
Authors: Graham Jean Ann , Kligman Albert M.
Published: May 2007

Synopsis

The relationships between physical attractiveness, cosmetic practices and self‐perception were examined in elderly females. Sixteen individuals of high and 16 of low attractiveness were evaluated with regard to ‘how they saw themselves’in terms of their behaviour, attitude, appearance, etc., and some aspects of their utilization of cosmetics.

The attractive evaluated themselves more highly than the unattractive on an overall measure of self‐perception, and they rated themselves more highly on a number of important individual dimensions of self‐perception: they perceived themselves as being healthier, with a greater feeling of wellbeing, as having a more positive outlook on life; as being more cheerful/less depressed, and better adjusted; they registered greater satisfaction with their lives; were more socially engaged; and more realistic.

Attractiveness did not appear to be correlated with the aspects of cosmetic practices examined. The physically attractive and unattractive did not differ significantly with respect to cosmetic usage (frequency and number of products), attitude towards cosmetics, history of cosmetic care, or difference between their cosmetic and basic attractiveness.

Since our previous research1 on this subject sample has shown that the unattractive elderly benefit from cosmetic therapy more than the attractive ‐ not only in terms of appearance but psychologically ‐ it is suggested that explicit training in effective cosmetic usage as used in cosmetic therapy programmes could help to bridge the psychological gap between the handsome and unhandsome elderly and reduce discrimination against the unhandsome elderly.
Evaluation of the anti‐inflammatory activity of biolysat hafnia®, in vivo in man
Authors: DUBERTRET L. , LEBRETON C.
Published: May 2007

Synopsis

‘Biolysat Hafnia®', an active principle, whose anti‐inflammatory activity had been demonstrated in animals, also has anti‐inflammatory properties in vivo in human volunteers as shown by the technique of migration chambers after suction blisters.

Évaluation de l'activité anti‐inflammatoire du Biolysat Hafnia®, en vivo chez l'homme
Preservative stability and preservative systems
Authors: TOLER J. C.
Published: May 2007

Synopsis

The stability of cosmetics must be examined from a chemical, physical and biological viewpoint. Biological stability is dependent on many factors including preservative effectiveness, preservative stability and the levels of initial and in‐use contamination.

Bronopol, a highly active preservative with less than ideal stability in alkaline systems, may be usefully combined with more stable preservatives whose activity is generally lower at high pH. Some consequences of preservative decomposition are discussed.

Mélange et stabilité d'agents conservateurs
Studies on the dermal toxicity of p‐phenylene diamine
Authors: VISWANATHAN P. N. , GUPTA V. , MISRA V.
Published: May 2007

Synopsis

Single dermal application of p‐phenylene diamine in guinea‐pigs caused pathomorphological lesions over a period of 24 h which later disappeared. Lipid peroxidation activity of skin homogenate showed significant inhibition, whereas superoxide dismutase was unaffected. Histamine content increased initially but showed drastic reduction during recovery. The significance of the data in the potential dermal toxicity of hair dyes is discussed.
Comparison of selection procedures for the formation of homogeneous groups in clinical tests of dental care agents
Authors: BILL E. , KLUEPPEL H.‐J.
Published: May 2007

Synopsis

Dental trials of new dental care formulations are studied with regard to specific quality characteristics such as inhibition of plaque formation and reduction of gingival bleeding, and require homogeneous panels of test persons in which both systematic and random sources of experimental error are excluded. The homogeneous panels must be formed from an available pool of test persons (global panel) so that each panel as a subset presents the same dental features on average and can be compared statistically one with another. This is a necessary condition for a valid scientific conclusion to be obtained from comparative dental studies. This type of homogeneous group division of a global panel can clearly be based on other medical features.

Four selection procedures for the formation of homogeneous panels from the global panel were compared quantitatively with regard to their efficiency and homogeneity of group division, namely:

— randomization method;

— block target method;

— median pair method;

— block median pair method.

With the exception of the randomization method, which can be applied more generally, the other selection methods require a preliminary study of the available test persons with regard to their medical features.

A comparison of the four selection procedures shows that the three other methods are more likely to provide more homogeneous panels than the randomization method.

Comparaison des procedures de selection concernant la formation de groupes homogènes dans les tests cliniques des agents de soins dentaires
Substantivity of sunscreens: an appraisal of some quaternary ammonium sunscreens
Authors: SAETTONE M. F. , GIANNACCINI B. , MORGANTI C. , PERSI A. , CIPRIANI C.
Published: May 2007

Synopsis

Two series of quaternary ammonium UV‐B sunscreens, derived from salicylic acid (S) and from p‐methoxycinnamic acid (C), and containing N‐alkyl chains of different length (C2 to C16) were prepared and submitted to substantivity tests on animal (wool) keratin, and to microbiological tests. A direct correlation between substantivity and antimicrobial/antifungal activity was observed in all cases, the compounds bearing C12 alkyl chains displaying peak values. The C‐derivatives, when compared with the S‐derivatives, showed relatively higher substantivity and sunscreen index (SI) values, coupled with lower antibacterial activity. The substantivity‐microbiological activity correlations and the particular behaviour of the C12 derivatives are briefly discussed in the light of the existing literature data. On the basis of the experimental results, possible guidelines for the development of substantive and non‐antibacterial (and possibly, non‐irritant) quaternary ammonium sunscreens are indicated.

La substantivité des filtres solaires
Location and nature of the epidermal permeability barrier
Authors: BOWSER P. A. , WHITE R. J. , NUGTEREN D. H.
Published: May 2007

Synopsis

The lowest region of human and pig stratum corneum has been isolated as an integral layer, referred to as the stratum compactum. This preparation is resistant to disruption by enzymes, 6M urea, Triton X‐100 and organic solvents. Our evidence suggests that penetration of materials to and through the corneum depend on the state of cohesion between cells, and of the organization of intercellular lipid species. As the cells move up towards the outside of the stratum corneum, the cohesive forces are reduced due to desmosome degradation and lipid modifications, with ultimate dyshesion and sloughing of individual cells.

A number of linoleate‐rich lipids have been identified within human and pig epidermis which could contribute to the formation or maintenance of an epidermal permeability barrier. Our current belief is that the molecule key to barrier function is a hydroxylated linoleate derivative which appears to be formed in the stratum compactum region.

Situation et nature de la barrière de perméabilitéépidermique
The epidermal engine: a commentary on epidermopoiesis, desquamation and their interrelationships
Authors: MARKS R.
Published: May 2007

Synopsis

The physiology and methods for study of epidermal cell production are reviewed. The importance of desquamation to any consideration of epidermal cell population size is stressed. Techniques for the measurement of the rate of desquamation are described with particular emphasis on quantitative dansyl chloride clearance time methods. Although the rates of cell production and cell loss must be related, the possibility of aberrations from a strict equivalence are discussed. Finally, the questions of the control of epidermopoiesis and the changes that occur with ageing are discussed.

La fonction épidermique
Corrélation d'une technique d'analyse d'images et d'une méthode profiométrique dans l'étude des rides de la patte d'oie
Authors: SCHMIDT C. , CAMUS C. , CAUDIU H. , HER C. , SOUDANT E. , BAZIN R.
Published: May 2007

Il existe plusieurs méthodes pour appréhender le relief cutané. La profilométrie consiste à enregistrer le contour relevéà l'aide d'un palpeur sur une empreinte de la peau en Araldite (positif). L'analyse d'images détecte les ombres portées par un éclairage rasant sur une empreinte souple de la peau (négatif). Ce travail s'attache à comparer les deux méthodes et à discuter l'utilité de chacune, à partir d'empreintes réalisées sur la patte d'oie de l'oeil.
A novel proposal for the assessment of sunscreen product efficacy against UVA
Authors: STOCKDALE M.
Published: May 2007

Synopsis

The ideal characteristics are outlined for an assessment method for the protective properties of sunscreen products against UVA. Existing sun protection factors (SPFs) are reliant on largely UVB‐induced delayed erythema, which is inappropriate for the UVA. A novel instrumental method for assessing a protection index is detailed which is applicable to the UVA. The validation of the method relies on measurements in the UVB and comparison with conventional SPFs, since no reliable UVA protection index exists. The method uses UV transparent skin casts to which products can be applied. Throughput of appropriately filtered light, with and without applied product, is measured to generate a protection index. Comparison with SPFs confirms that the measurements are similar to those generated by in vivo methods, but that careful choice of the casting medium is essential.
Thixotropy
Authors: Cheng D. C.‐H.
Published: May 2007

Synopsis

This paper summarizes the characteristics of thixotropic behaviour and gives examples of industrial materials that show this property. It reviews the physical and chemical bases of thixotropy and discusses the theoretical derivation of mode constitutive equations. Measurement techniques are described and some results are given. The paper concludes with a brief discussion of application of measurement results.
Routine patch testing with the preservative system Kathon CG
Authors: GROOT ANTON C. DE , BRUYNZEEL DERK P. , SCHROEFF JAN GERRIT VAN DER , BOS JAN D.
Published: May 2007

Synopsis

Of 1620 patients routinely patch tested with Kathon CG 100 p.p.m. aqua for suspected allergic contact dermatitis, 81 (5.0%) had a positive reaction. Sixty‐two reactions (3.8%) were relevant for the dermatitis for which the patient consulted the dermatologist. Most patients were females who presented with dermatitis of the hands and/or face. Forty‐six per cent of the patients had become sensitized by using cosmetic products on healthy skin. The other 54% had pre‐existing dermatitis, especially atopic dermatitis and irritant dermatitis. Most reactions were caused by moisturizing creams.
Percutaneous absorption of p‐phenylene diamine during an actual hair dyeing procedure
Authors: GOETZ NOËL , LASSERRE PIERRE , BORÉ PIERRE , KALOPISSIS GRÉGOIRE
Published: May 2007

Synopsis

An analytical method has been developed that allows the determination of p‐phenylene diamine derivatives in urinary samples collected from women after hair dyeing with commercial formulations. During an on‐line flash hydrolysis of the urine, a number of metabolites of p‐phenylene diamine were hydrolyzed to free p‐phenylene diamine, which was then determined using gas chromatography‐mass spectrometry. The excretion of metabolites of p‐phenylene diamine could be followed during 24 or 48 hours after the dye had been applied. Most of the p‐phenylene diamine cleaved by the flash hydrolysis procedure was, in fact, involved in the N,N′‐diacetyl combination. The dose excretion for p‐phenylene diamine as measured by this method was comparable to that found by other authors who made use of radioactively labelled material. The present analytical method can be used to evaluate procedures intended to decrease the percutaneous absorption of p‐phenylene diamine. Thus, a five‐ to ten‐fold decrease in its penetration was observed by protecting the scalp with clay before applying the dyeing composition.
Optical methods for measuring the pearlescent effect in toiletries
Authors: MILLER DENNIS J. , RENG ALWIN K. , SKRYPZAK WERNER
Published: May 2007

Synopsis

Pearling agents used to improve the appearance of toiletries are generally judged visually, as it is difficult to devise suitable quantitative tests. If a pearling agent is added to a stirred liquid, moving light and dark patches may be seen. A method has been developed to put this simple test on a quantitative basis. The reflected light is measured using a fibre optic probe. An on‐line computer calculates the ratio of the standard deviation to the mean of the intensity; this is a measure of the pearlescent effect. By combining such measurements with turbidity data, a two‐parameter description of the appearance of the product is obtained. The method may be used for quality control, comparison of commercial formulations or to monitor changes during storage.
Photoallergic potential in the guinea‐pig of the nitromusk perfume ingredients musk ambrette, musk moskene, musk xylene, musk ketone, and musk tibetene
Authors: LOVELL W. W. , SANDERS D. J.
Published: May 2007

Synopsis

The nitromusk perfume ingredient, musk abrette, has been reported to cause photoallergic reactions in man. The potential of alternative, chemically related, nitromusks to cause photoallergy has been studied using the Colworth guinea‐pig photoallergy test.

The results showed that, compared with musk ambrette, musk moskene had a weak potential for inducing photoallergy, and that the musks xylene, ketone and tibetene had only very weak potentials. A study of photo‐crossreaction to musk ambrette showed that musk moskene was active, musk xylene was weakly active, while the musks ketone and tibetene were inactive.

We conclude that musk moskene is likely to be less hazardous for man than musk ambrette, but caution should be used in selection of concentrations for use on sun‐exposed skin. The musks xylene, ketone and tibetene are likely, photobiologically, to be acceptable alternatives to musk ambrette. The photoallergic potential of the nitromusks can, probably, be related to chemical structure.
Simulated consumer exposure to propellant HCFC 22 (chlorodifluoromethane) in aerosol personal products
Authors: HARTOP P. J. , ADAMS M. G.
Published: May 2007

The potential human exposure to the aerosol propellant HCFC 22 (chlorodifluoromethane) arising from its use in personal products has been assessed. HCFC 22 concentrations were measured in the ‘breathing zone' of an experimental manikin and an ‘accompanying child' designed to simulate human use of hairsprays, body sprays and antiperspirants in a closed room. Results were expressed as the 10‐min time‐weighted average concentration in the air (TWA 10) and as the peak concentration in the ‘breathing zone' of the ‘user’.

Following a 10‐s use of hairspray containing approximately 20–40% HCFC 22, TWA10 values for an adult user and child were 64–116 ppm and 44–100 ppm, respectively. Use of an aerosol body spray containing 20–65% HCFC 22 for 5–20 s gave rise to TWA10 values of 32–411 ppm for an adult user and 20–395 ppm for a child. A 4‐s use of an antiperspirant containing approximately 20–40% HCFC 22 sprayed at a distance of 10–30 cm from the breathing zone of the adult user generated TWA 10 values in the range of 14–34 ppm for both the adult user and child. Opening the door of the room prior to hairspray and antiperspirant spraying slightly reduced these TWA 10 values. The peak values recorded in these studies for the adult user were 208 ppm for hairspray, 1415 ppm for body sprays and 82 ppm for antiperspirants.
Changes in surface configuration of the skin caused by ageing and application of cosmetics: three‐dimensional analysis according to a new system based on image analysis and Fourier transformation
Authors: HAYASHI S. , MIMURA K. , NISHIJIMA Y.
Published: May 2007

Synopsis

The surface configuration of the skin, as characterized by surface furrows and plateaux, is known to change with ageing and skin condition. There have been many attempts to analyse the surface configuration in order to evaluate the effect of skin care products. However, the systems proposed up to now are insufficient to obtain three‐dimensional data.

A system based on image analysis and Fourier transformation has been developed. By using this system, we can make a quick and quantitative analysis of the three‐dimensional surface configuration of the skin. This system was applied to measure changes in the surface configuration with ageing, and to clarify the effects of cosmetic cream.

As a result, it was found that the furrows become less clear, become parallel in one direction and the texture becomes coarse and irregular, as ageing continues. These changes are believed to correspond to deterioration of the metabolic and moisturizing functions of the skin.

It was also found that the furrows become clear and the texture becomes finer after the application of cream than before. This is believed to be the result of the improvement of the skin condition due to the moisturizing effect of the cream.
Hyaluronic acid: analytical procedures for purity determination, polymerization degrees and comparative instrumental test ‘in vivo’
Authors: FIORENTINI G. , BECHERONI L. , IORIO G. DI
Published: May 2007

Synopsis

Recent studies have shown that hyaluronic acid is an important molecule in cosmetics, although there are different, sometimes controversial theories about its role.

This work is an analytical contribution to the characterization and control of hyaluronic acid. The main techniques used are UV, GCP or SEC, IR and corneometry.

Surveys conducted with the aid of these techniques have allowed a better knowledge of the molecular weight determination and of the uniform quality of commercial supplies.

These procedures may be of application for quality control and promote further investigation on the biological tissular role played by hyaluronic acid in topical cosmetic products.

The analytical results of a study of the evaluation of oil/water (o/w) emulsions containing hyaluronic acid of different origins are reported. The analytical data obtained from cutaneous hydration control apparatuses were compared statistically.

The choice of hyaluronic acid, made through screening and evaluation by the abovementioned techniques, ensures the optimal formulation of the finished product and a quality standard of the active principle.
Contributions to the chemistry of human hair: II. Lipid chemical aspects of permanently waved hair
Authors: HILTERHAUS‐BONG SABINE , ZAHN H.
Published: May 2007

Synopsis

The cell membrane complex (CMC) and the internal lipids of untreated and permanent waved hair were investigated. The permanent waving procedure results in a lower amount of the cell membrane fraction that could be isolated compared to untreated hair. There is no difference in the amino acid composition of the CMC fractions. The internal hair lipids were extracted from the CMC fraction with chloroform/methanol. For untreated human hair the cell membrane complex yields 57% of lipid material, whereas from the CMC of permanent wave hair only 35% of lipids could be extracted. The polar lipids and the fatty acids are the main components of the internal hair lipids. After a permanent waving treatment there is a distinct decrease in the polar lipid fraction which is higher at alkaline (pH 9) than at neutral pH (pH 7). The reduction treatment at pH 9.0 also causes a cleavage of the fatty acid fraction in the internal hair lipids.
Skin permeability to aromatic carboxylic acids: an in vitro comparison in pig ear, white mouse and brown mouse
Authors: DYER A. , AZIZA M. A. E.
Published: May 2007

Synopsis

A comparative study in vitro was undertaken for pig ear, white mouse, and brown mouse in which the percutaneous absorption of the following compounds, labelled with 14C‐carboxyl, were studied: benzoic acid, 2‐methylbenzoic acid, and 4‐methylbenzoic acid. The effects of temperature on the penetration through various skin membranes have been evaluated. The possible influences of chemical structure on transport across the skin were discussed. The results indicated that brown mouse skin was the most permeable membrane to all acids. Introduction of the methyl group to the aromatic ring, in the ortho and in the para positions, increased the diffusion coefficients for the benzoic acid.
Hydrolysed ginseng‐saponin quaternary: a novel conditioning agent for hair care products
Authors: YOUNG‐DAE KIM , CHANG‐KEW KIM , CHUNG‐NAM LEE , BYUNG‐JO HA
Published: May 2007

Synopsis

A new quaternary ammonium compound, hydrolysed ginseng‐saponin quaternary (HGSQ), from Korean ginseng saponin and 2,3‐epoxypropyltrimethyl ammonium chloride, has been developed as a conditioning agent for hair care products. This structure has a hydrophobic group from the aglycone of ginseng saponin which is biologically active and considered as the most important component of Korean ginseng. Its properties of surface tension, conductivity, critical micelle concentration (CMC), eye irritation, sorption onto hair, tensile strength for 20% extension and moisture retention effect were studied. Its cationic character allows the molecule to be more substantive than ginseng saponin. HGSQ had good physical properties and was safe enough as a cosmetic raw material. Also half‐head tests of HGSQ‐containing shampoo were carried out to evaluate the conditioning effects in shampoos. HGSQ showed good conditioning properties in a shampoo.
Contributions to the chemistry of human hair: III. Protein chemical aspects of permanent waving treatments
Authors: HILTERHAUS‐BONG SABINE , ZAHN HELMUT
Published: May 2007

Synopsis

The influence of permanent waving on hair proteins was studied in order to obtain additional information about the chemistry of this cosmetic treatment. It was shown by amino acid analysis that with increasing reduction time during treatment fewer disulphide bonds were reformed in hair during subsequent reoxidation. Simultaneously, an increasing amount of sulphur‐containing material is liberated from the hair, as demonstrated by the sulphur balance calculated from the sulphur‐containing amino acids. The amount liberated is increased when an extensive soaking of the samples in water between the reduction and reoxidation step is performed. Comparing treatments with the use of reducing solutions of pH values between 7.5 and 10.0, it was found that the largest amount of cystine cleavage occurs at pH 9.0. All hair samples reduced at pH values above pH 8.5 showed incomplete reformation of the disulphide bonds during subsequent reoxidation. This was indicated by the content of free SH‐groups and cysteic acid, as quantified by amino acid analysis. The damage to the hair proteins due to permanent waving was further confirmed by the determination of the pronase solubility. The reductive treatment of hair at pH 7.5 led to a relatively low degree of reduction, however all sulphur bonds were reformed during subsequent reoxidation.
Structure/activity relationships in contact allergy
Authors: BASKETTER D.A. , ROBERTS D.W.
Published: May 2007

Synopsis

To minimise consumer risk of allergic contact dermatitis, predictive testing may need to be carried out. An alternative approach examining physicochemical properties of substances, and from these trying to assess sensitization potential, formed the basis of a model described by Roberts and Williams [1]. The concept related electrophilic reactivity (k), the partition coefficient (P) and dose (D) in a term which described a relative alkylation index (RAI). This was shown to correlate well with experimental data for sultones and p‐nitrobenzyl halides: RAI =kD/(P±P2) (1)

In recent studies of dose response relationships, the ‘overload effect’ predicted by Roberts and Williams is demonstrable. However, the simple relationship above omits two potentially important parameters, ‘intrinsic antigenicity’ of a chemical and activation in skin of an apparently unreactive chemical. Data on the sensitization potential of alkyl transfer agents shows that for small haptens, intrinsic antigenicity may depend in part on the nature of modifications to carrier protein tertiary structure. The ability of skin to metabolise 1,4‐substituted benzene derivatives in vivo appears even more complex than suggested [2], involving a spectrum of reactive intermediates characteristic of each molecule.

These results suggest that the RAI formula needs to be modified.
Screening tests for free radical scavengers on cutaneous cultured cells.
Authors: NOEL‐HUDSON M.S. , CORNELIS M. , LINDENBAUM A. , WEPIERRE J.
Published: May 2007

Synopsis

Numerous studies discuss the important development of free radicals in human skin after exposure to UV irradiation. They suggest that these reactive molecules are responsible for sun‐accelerated cutaneous aging.

We reproduced two types of radical agression on cutaneous human cell cultures. The first brings into action oxygen radicals generated by hypoxanthine‐xanthine oxidase system and the second involves the use of UV radiation. These complementary models may be used as screening methods for antioxidant molecule research because they allow the distinction between molecules with filtering properties and free radical scavengers. The possibility of introducing molecules at different stages (before, during and after exposure to agression) permits the study of the molecular mecanism. These models were tested on silymarin, catechin, ascorbic acid and alpha tocopherol.
Emulsification by the phase inversion temperature method: the role of self‐bodying agents and the influence of oil polarity
Authors: FÖRSTER TH. , SCHAMBIL F. , TESMANN H.
Published: May 2007

Synopsis

Oil‐in‐water emulsions stabilized with nonionic emulsifiers change to water‐in‐oil emulsions as the temperature rises when the hydrophilic and lipophilic properties of the mixed emulsifier are just balanced. Preparation above the phase inversion temperature followed by rapid cooling yields emulsions that exhibit very fine droplet size and extreme long‐term stability. Cosmetic emulsions were prepared by this phase inversion temperature (PIT) method using typical raw materials such as polar oils, e.g. decyl oleate, 2‐octyl dodecanol or isopropyl myristate, and nonionic emulsifiers, e.g. ceteareth‐12 or polyoxyethylene eicosyl/docosyl ether combined with cetostearyl alcohol as a co‐emulsifier. The phase inversion temperature was measured as a function of the oil polarity and the concentration of mixed emulsifier. The relationship between phase inversion temperature, droplet size and emulsion stability was investigated. In addition, self‐bodying agents such as cetostearyl alcohol or monoglycerides were added to these thin, fine disperse emulsions to adjust the consistency. The influence of these ingredients on phase inversion temperature, droplet size, yield value and emulsion stability was studied.
Identification des filtres UV dans les produits cosmétiques par CCM et HPLC
Authors: MASSE M.O. , HERPOL‐BORREMANS M.
Published: May 2007

Synopsis

The method describes the identification of 22 UV filters authorized in Cosmetic products in Europe (dir. 76/768 EEC, annex VII, modified by dir. 89/174 EEC). (Table I).

Twelve UV filters registered in part 2 of annex VII (dir. 83/574EEC) provisionally allowed in 1983 were abandoned by Industry. Consequently they were suppressed from the list of UV filters which cosmetic products may contain (dir. 89/174 EEC). Nevertheless the method describes also the identification of these 12 chemicals because they could interfere with the analysis of the 22 authorized UV filters in view of similarities in chemical structures (Table I (suite)).

The screening of the UV filters in final products is based on thin layer chromatography (TLC) and confirmed by high pressure liquid chromatography (HPLC/UV).

TLC combines four different systems and several detection reagents: absorption chromatography on silica gel with development in a neutral solvent, an acidic solvent, a basic solvent, reversed phase chromatography on RP 18 bonded silica with development in a methanol/water mixture.

The results of these screening tests are confirmed by reversed phase HPLC/UV in an isocratic elution system. The acid components and the salts which are eluted before or with the solvent peak are separated in a gradient elution system at pH 3.5.

Several UV filters available on the market of cosmetic ingredients are impure chemicals or mixtures.

The identification of their principal components by nuclear magnetic resonance spectrometry (NMR) and by gas chromatography/mass spectrometry (GC/MS) will be the subject of future publications.
Biosurfactants for cosmetic applications
Authors: BROWN M.J.
Published: May 2007

Synopsis

Biosurfactants are biologically‐produced, natural surface active agents and are synthesized by a range of microorganisms. These compounds include glycolipids, lipopeptides and phospholipids. The yields of biosurfactants in microbial fermentations may be as high as 150g l−1 and may be increased by optimizing production conditions and by strain improvement. Biosurfactants display very low critical micelle concentration (CMC) values when compared with conventional surfactants and are stable at a wide range of temperatures, pH values and salinities. They show many promising characteristics for cosmetic applications.
Mise en place d'un modèle in vitro d'étude du vieillissement cellulaire sur fibroblaste dermique humain
Authors: LAFFORGUE Ch. , ZABOT M.T. , COTTE J.
Published: May 2007

Synopsis

The normal dermal human fibroblastic cell (NDHF) was used to determine a cellular ageing pattern. Cells were cultured in monolayers until the 30th passage. First of all, the following cell growth characteristics were studied: growth rate, fluorimetric DNA determination, DNA repair after UV irradiation. Secondly, metabolism characteristics were examined: lysosomal enzymatic activity and type I and III collagen biosynthesis. Strains were obtained from 10,30,43 and 69‐year‐old donors to favour a comparison between in vitro and in vivo ageing.

Cell growth ability is modified in vitro only for the oldest strain which shows a significant decrease in the cellular density at the 30th passage. The DNA rate and its repairing ability are not changed by in vitro ageing whatever the strain age.

Lysosomal activity increases during in vitro ageing whereas the collagen I synthesis decreases.

In vitro proliferating potentialities do not reflect in vivo ageing. On the other hand, in this study, metabolic potentialities evolve in the same way in vitro as in vivo and could be a good enough pattern to select anti‐ageing products.
Influence of skin cleansing preparation acidity on skin surface properties
Authors: KORTING H.C. , MEGELE M. , MEHRINGER L. , VIELUF D. , ZIENICKE H. , HAMM G. , BRAUN‐FALCO O.
Published: May 2007

Synopsis

Two long‐term trials were conducted each over eight weeks to compare the effect of the regular application of skin cleansing preparations of pH 5.5 and pH 8.5 and pH 5.5 and pH 7.0 respectively on the surface pH, roughness and transepidermal water loss (TEWL) of normal human forehead and forearm skin. Both trials were based on a cross‐over design: five healthy volunteers started with a pH 5.5 preparation and switched to the other after four weeks, five additional volunteers used the preparations in the opposite order. While the skin surface pH was markedly lower in those individuals using the pH 5.5 preparation at each examination, as compared to those using the pH 8.5 or pH 7.0 preparation, no such difference could be established with respect to skin roughness and TEWL. Hence the skin irritancy of a cleansing preparation does not seem to be linked to its pH within the pH ranges tested.
Solution behaviour of new cationic surfactants derived from Guerbet alcohols and their use in hair conditioners
Authors: YAHAGI KAZUYUKI , HOSHINO NAOKO , HIROTA HAJIME
Published: May 2007

The solution behaviour of new cationic surfactants, synthesized by using long‐chain Guerbet alcohols, in water was investigated by a polarizing microscopic technique, differential scanning calorimetry, and electric conductivity measurements. These surfactants show the gel–liquid crystalline phase transition to be lower than 0°C and form lamellar liquid crystals even in cold water and at low concentrations of surfactants. The sorption of cationic surfactants from aqueous solutions onto hair was determined as a function of temperature. The effect of adsorbed cationic surfactants on the critical surface tension and kinetic frictional coefficients of hair surface have been investigated. These surface characteristics of hair treated with quaternary ammonium compounds derived from Guerbet alcohols were found to be significantly improved. These results can be explained by the high ability of sorption onto hair. Hair rinses and conditioners having excellent ease of combing or brushing for wet and dry hair can be formulated by the application of these cationic surfactants.
Sodium lauryl sulphate/amphoteric surfactant interactions: selective diffusion through a collagen film
Authors: DOMINGO X. , PHILLIPS B.M. , LEAL J. SANCHEZ , GARCIA T. , GARBAYO A.
Published: May 2007

Synopsis

Diffusion tests of anionic, amphoteric and mixtures of amphoteric/anionic surfactants have been performed using a collagen film.

A sensitive potentiometric method has been developed to determine the surfactant diffused avoiding the interferences observed in the usual analytical measurements due to the simultaneous presence of amphoteric/anionic surfactants.

From the results obtained it is evident that the surfactant mixtures exhibit a synergistic behaviour as there is a mutual inhibition of the surfactant diffused through the collagen film.

Empirical equations have been derived to describe the diffusion process of both the individual surfactants and mixtures of surfactants which allow the diffusion of the individual surfactants and the inhibition of diffusion in mixtures to be quantified.
Three phase emulsions for controlled delivery in the cosmetic field
Authors: BONINA F. , BADER S. , MONTENEGRO L. , SCROFANI C. , VISCA M.
Published: May 2007

Synopsis

Adding perfluoropolymethylisopropylether (Fomblin HC) to conventional cosmetic emulsion, causes the physicochemical and applicative properties of the formulation to be deeply modified, the main feature being the formation of three phase systems.

The in vitro effects on percutaneous absorption of adding Fomblin HC to a cosmetic emulsion of three model compounds was assessed using caffeine, testosterone and tritiated water as model compounds. In vitro experiments were carried out through human skin using static and flow‐through diffusion cells. The presence of Fomblin HC (1, 3, 5%) in the emulsion decreased the percutaneous absorption of testosterone (0.01%) but increased water permeation. These effects were dependent on Fomblin HC concentration. On the contrary, caffeine flux through the skin was not affected by Fomblin addition to the emulsion.
The effect of smoking on skin moisture and on surface lipids
Authors: WOLF RONNI , TUR ETHEL , WOLF DANNI , LANDAU MARINA
Published: May 2007

Synopsis

In the present retrospective study we investigated the effect of smoking on the moisture and surface lipid levels of the skin. We analysed data from the files of 576 female clients treated in a Tel‐Aviv cosmetic parlour. Measurements have been conducted by the same cosmetician, by commercially available equipment, on every client receiving cosmetic treatment, regardless of the nature of the treatment.

Results demonstrated a significant difference of skin moisture in the various smoking groups: women who smoked 11–20 cigarettes per day showed significantly lower mean values than the non‐smoker group, as expected. Moreover, women before or after menopause showed no significant differences in their moisture measurements.

The surface lipid variables showed no significant differences in mean over the four smoking groups.

We believe that the objective of the study was achieved, and that the results, indicating decreased skin moisture in smokers, will serve well in anti‐smoking campaigns. We also believe that the present study will stimulate other investigators to conduct similar studies that will provide answers to the many questions which still remain open.
Future developments in cosmetic formulations
Authors: TADROS T.F.
Published: May 2007

Synopsis

In recent years, there have been a great deal of interest in applications of microemulsions, liposomes (vesicles) and multiple emulsions in cosmetic formulations. These systems will provide the cosmetic industry with new types of formulations which are easier to apply, better functional benefit and potentially safer formulations. Microemulsions are thermodynamically stable systems and hence shelf life is no problem. Many cosmetic ingredients can be adequately solubilized in the swollen micelles of the microemulsions. Such solubilized systems may enhance transport and diffusion through various barriers, eg., the skin, thus enhancing the efficacy of the formulations. However, microemulsions may cause skin irritation by disrupting the liquid crystalline structure of the stratum corneum. This problem may be overcome by formulating microemulsions, which on evaporation produce lamellar liquid crystalline structures. The problem of skin irritation is certainly reduced or eliminated using liposomes or vesicles, which offer an alternative to microemulsions. The principles for formation and stabilization of vesicles are discussed in this paper and research work is needed to produce nanocapsules from liposomes, using polymerizable surfactants. Multiple emulsions of the water/oil/water (w/o/w) or oil/water/oil (o/w/o) types are also valuable systems for formulating cosmetics. In the first place, they offer a means of sustained release of the various ingredients. Secondly, they allow one to separate the various ingredients in the formulation, thus preventing their possible interaction. The basic principles required for preparation of stable multiple emulsions are summarised. Developments of polymeric surfactants led to the formulation of stable multiple emulsions. An example of a recently formulated stable w/o/w multiple emulsion is given in this paper The stability of the system was investigated using optical microscopy. Creaming occurred on storage, particularly at high temperature (40°C) and this was significantly reduced by addition of Kelzan (a polysaccharide with high molecular weight). The final formulation was studied rheological techniques.
Method for quantifying cutaneous pigmentation in animals and preliminary study in humans
Authors: MEROT F. , SENIUTA R. , BENITA G. , MASSON Ph.
Published: May 2007

Synopsis

A preoccupation with aesthetics and a real desire for social development has brought about an increase in the demand for safe, effective depigmenting products among African and Asian populations.

For many years now, we have used an experimental model which uses the black mouse CS BL/6/JICO.

As a result of developing needs and the necessity to check the results obtained from animals on humans, we have had to change the methodology in order to take into account the specific characteristics of human skin.

After a summary of the protocol used on the mouse, here you will find a description of the technical changes which had to be made in order to carry out the study on humans.

The results of a comparative test between the two models are given. This was carried out with a cosmetic preparation containing 2% hydroquinone introduced via a vector that facilitates its absorption.

The depigmentation observed in the animal model was not found significant in humans.

Taking into consideration the large number of differences between individuals, and in order to demonstrate a significant result on humans, it would be necessary to use a larger experimental group, treated for a longer period than that normally used with animals.
Determination of methyldibromoglutaronitrile in cosmetic products by high performance liquid chromatography with electrochemical detection
Authors: ROOSELAAR J. , WEYLAND J.W.
Published: May 2007

Synopsis

A method for the determination of methyldibromoglutaronitrile in cosmetic products is described. Reversed phase high performance liquid chromatography and reductive electrochemical detection is employed to provide for improved selectivity and detectability compared to alternative methods. The method detects 0.002% methyldibromoglutaronitrile in cosmetic products and has a linear range from 0.006 up to 0.06%, which can easily be extended to the legally allowed limit of 0.1% by means of a simple dilution step. At a level of 0.03% the coefficient of variation was estimated to be 1.7%. Recoveries measured were between 98 and 100%.

The method has been subjected to a ruggedness test, which indicated that it was stable, but slightly sensitive for a decrease in the detection potential. More than 130 cosmetic products have been analysed using the method. In 19 samples methyldibromoglutaronitrile was detected in concentrations varying between 0.002% and 0.030%.
Substantivity of sunscreens —in vitro evaluation of the transdermal permeation characteristics of some benzophenone derivatives
Authors: MONTI D. , SAETTONE M.F. , CENTINI M. , ANSELMI C.
Published: May 2007

Synopsis

The in vitro permeation through excised hairless mouse skin of a series of 4‐O‐(N, N‐dimethylaminoalkyl)‐benzophenones, non‐quaternarized and quaternarized, and of two commercial benzophenone sunscreens, taken as reference compounds, was investigated. The aim of the study was to verify the skin penetration of the highly skin‐substantive quaternary ammonium derivatives, in comparison with their parent, non‐quaternarized compounds. While the quaternary derivatives proved unable to permeate the skin during the period of observation (45 h), their parent amine hydrochlorides and the reference sunscreens (2‐hydroxy‐4‐methoxy‐benzophenone‐5‐sulphonic acid and 2,2′‐dihydroxy‐4,4′‐dimethoxy‐benzophenone 5,5′‐sodium disulphonate), showed appreciable transdermal fluxes.

These data indicate that the presence of a quaternary ammonium group in a molecule, besides inducing a high affinity for cutaneous keratin, may result in hindered or reduced transdermal (and possibly systemic) absorption. Both features may contribute in improving the safety of a cosmetic sunscreen.
Rheology: how to characterize and to predict the evolution of W/O/W multiple emulsions
Authors: TERRISSE I. , SEILLER M. , RABARON A. , GROSSIORD J.L. , MAGNET A. , Le HEN‐FERRENBACH C.
Published: May 2007

Synopsis

The purpose of this work was to compare the evolution of three multiple emulsions (ME) by different controls. The series of water‐in‐oil‐in‐water (W/O/W) multiple emulsions were elaborated and controlled by both the usual analyses which permitted the classification of the multiple emulsions with respect to their thermal stability, and the rheological oscillatory and flow analyses which are polyvalent methods. Further, these allow the ‘identity card’ of the multiple emulsion to be drawn, its evolution to be followed, and moreover, its behaviour being foreseen by simulating ageing by shear. Three different behaviours are observed; a destructuration, a phase inversion and stability.
A BUREAUCRAT'S PROCUREMENT STRATEGY: BUDGET CONSTRAINTS AND RATIONING
Authors: ANTHON Signe , BOGETOFT Peter , THORSEN Bo Jellesmark
Published: May 2007

ABSTRACT**:  We investigate a bureaucratic principal responsible for the procurement of goods and services from private agents. The bureaucrat is evaluated on output and controlled by a limited budget. The agents maximize profit, have private information about variable production costs, and have positive outside options which are lost upon acceptance of a procurement contract. The setting is relevant for, e.g. governmental agencies. We show how this setup makes probabilistic rationing and overproduction for low‐cost agents a useful tool for the bureaucrat.
Counting Backward to Health Care's Future: Using Time‐to‐Death Modeling to Identify Changes in End‐of‐Life Morbidity and the Impact of Aging on Health Care Expenditures
Authors: PAYNE GREG , LAPORTE AUDREY , DEBER RAISA , COYTE PETER C.
Published: May 2007

In most developed countries, as the largest population cohorts approach the age of sixty‐five, the impact of population aging on health care expenditures has become a topic of growing interest. This articles examines trends in elderly disability and end‐of‐life morbidity, estimations of the cost of dying, and models of expenditures as a function of both age and time‐to‐death and finds broad improvement in mortality and morbidity among the elderly in the developed world. Reduced mortality and low growth in the costs associated with dying could reduce forecasted expenditures, but high growth in expenditures for those not close to death and for nonhospital services could create new economic pressures on health care systems.