bluuebunny/crossref_metadata_2025 huggingface dataset:
Contributions to the chemistry of human hair. 1. Analyses of cystine, cysteine and cystine oxides in untreated human hair
Authors: HILTERHAUS‐BONG SABINE , ZAHN HELMUT
Published: May 2007

Synopsis

Amino acid analysis, photometry and polarography were selected as analytical methods for the determination of thiol and disulphide groups in untreated human hair and the results are discussed. The pre‐treatments necessary for the different analytical methods, e.g., hydrolysis, to some extent already induce chemical changes of the cysteine and cystine derivatives leading to method‐dependent differences in the results. In many cases the partial oxidation products of cystine are supposed to be responsible for this effect. Electron Spectroscopy for Chemical Analysis (ESCA), as an analytical method for the determination of the cystine oxides, was found to be inapplicable due to insufficient resolution and sensitivity, whereas by the use of Fourier Transform Infrared (FTIR) Spectroscopy the sulphur‐oxygen vibrations could be analysed and cystine monoxide and cystine dioxide were detected.
Study of the optical properties of human hair
Authors: GUIOLET A. , GARSON J. C. , LEVECQUE J. L.
Published: May 2007

Synopsis

The optical properties of human hair were studied by photogoniometry. Starting from an optical model of hair, we developed a computerized method of decomposition of the goniophotometric curve. From our analysis we obtained structural parameters of the hair surface, average scale angle and cosmetic parameters like lustre and pigmentation. This method gave us new results in the following areas:

— the effects of bleaching on scale and internally reflected light;

— the study, from root to tip, of surface damage and hair pigmentation;

— the effects of stretching the hair on scale angle and lustre;

— the effects of sebum and dust on hair lustre.
The spectral stability of several sunscreening agents on stratum corneum sheets
Authors: KAMMEYER A. , WESTERHOF W. , BOLHUIS P. A. , RIS A. J. , HISCHE E. A.
Published: May 2007

Synopsis

Film layers of seventeen commercially available sunscreen products and sixteen active ingredients on stratum corneum sheets were spectrophotometrically monitored before and after simulated solar irradiation. Fixed irradiation doses were given within the daily terrestrial limits. From the changes in the absorption spectra after irradiation the spectral stability was determined. The spectral stability reflects the photochemical stability and the assay quickly provides an insight in the sunscreen's stability towards (solar) radiation in situ. Good to excellent spectral stability was observed for the benzophenones, paraaminobenzoic acid and its esters, homomenthylsalicylate, guanine, 2‐phenylbenzimidazol‐5‐sulphonic acid (potassium salt) and guiazulene. Moderate spectral stability was observed in case of the cinnamates and 3‐[4‐methylbenzylidene] camphor.

Poor spectral stability was exhibited by phenylsalicylate and 4‐isopropyldibenzoylmethane. Among the commercial products good to poor spectral stability was established.

We recommend the performance of this assay on every sunscreen agent or cosmetic formulation which may be exposed to the sun or any other ultra‐violet/visible radiation source.
Analysis of domiphen bromide and cetylpyridinium chloride in cosmetic products by high‐performance liquid chromatography
Authors: DE BUKANSKI B. WYHOWSKI
Published: May 2007

Synopsis

HPLC separation and quantitative determination of aromatic quaternary ammonium compounds in cosmetic products by means of cation‐exchange silica gel material and UV spectrophotometric detection.
Influence of microemulsion structure on cystine reactivity with keratin fibres
Authors: SOLANS C. , PARRA J. L. , ERRA P. , AZEMAR N. , CLAUSSE M. , TOURAUD D.
Published: May 2007

The activity of thioglycolic acid, incorporated in a microemulsion, towards cystine residues present in keratin proteins has been investigated.

In an attempt to relate the structural state of the microemulsions to cystine reactivity, an appropriate model system showing a large microemulsion domain with diverse structures was chosen.

The realm of preferentially hydrocarbon‐continuous microemulsion‐type media was found to induce the highest activity.
Physical changes in hydrated skin
Authors: VAN DER MERWE ERNA , ACKERMANN CHRISITA
Published: May 2007

Synopsis

A phenomenon of increased permeation as a function of time in the percutaneous absorption of urea and water led to this in vitro study with skin of hairless mice in a closed diffusion cell system. The Latin square method was used to assess the effect of four variables, namely temperature, time of hydration, concentration of urea and stirring of the donor‐and receiver‐cell phases on the physical structure of the skin and the permeability coefficients of urea and water. The scanning electron microscope and the transmission electron microscope were used to assess the physical changes in skin structure.

Temperature and time of hydration, but not the concentration of urea or the stirring of the donor‐ and receiver‐cell phases, affected the permeability of the skin to urea and water. The scanning electron microscope and transmission electron microscope micrographs confirmed these results.
Adverse effects of cosmetics and toiletries: a retrospective study in the general population
Authors: de GROOT A. C. , NATER J. P. , van der LENDER R. , RIJCKEN B.
Published: May 2007

Synopsis

Of 1609 individuals who were interviewed and asked whether they had experienced adverse reactions to cosmetics or toiletry products in the preceding 5 years, 196 (12.2%) claimed to have experienced some such reaction.

Females (n= 124) mostly attributed their complaints to soap (41%), facial creams (33%), deodorant (25%), shampoo (16%) and eye shadow (11%). Men (n= 72) complained about adverse effects from soap (49%), aftershave (22%), deodorant (19%) and shower foam (12%). Both in women and in men, most reactions were localized on the face (60% resp. 33%), followed by the hands (19% resp. 21%) and the axillae (18% resp. 14%). The majority of patients could solve the problem by stopping the use of the suspected product and purchasing a different brand. Nevertheless, medical consultation was sought by more than 30% of all patients.

Presumably, the majority of all adverse effects were caused by irritation; contact allergic reactions are infrequent.
Perfume interactions with sodium dodecyl sulphate solutions
Authors: BEHAN J. M. , PERRING K. D.
Published: May 2007

Synopsis

Vapour phase concentrations of aroma chemicals above a model shampoo system containing sodium dodecyl sulphate (SDS) have been measured using headspace gc methodology.

It was shown that, to a first approximation, headspace concentrations were directly related to the phase volumes ratio (water/SDS), and that this could be rationalized in terms of simple partitioning. The headspace behaviour of the same materials dissolved in water and in diethyl phthalate was also investigated with a view to understanding the effect of the medium on the perfume ‘profile’. The octanol/water partition coefficient was identified as a potentially useful parameter in this connection.

Since the phase structures of the surfactant systems were not known, the results for all the materials were expressed in terms of ‘apparent activity coefficients’, calculated from headspace concentrations and mole fractions. It was found that, to a first approximation, the headspace concentration of benzyl acetate above these surfactant systems was directly proportional to the phase volumes ratio (water/SDS), and that this could be rationalized in terms of a simple partition model. It was clear, however, that a more sophisticated model would require data on the surfactant/perfume component interaction in the absence of water—such data could be more conveniently obtained using liquid analogues of SDS.
Investigation des mécanismes de liaison impliqués dans la cohésion des compacts a usage cosmétique
Authors: KOMPAORÉ FRANCIS , PONCHEL GILLES , BOELLE ANNE , DUCHĚNE DOMINIQUE
Published: May 2007

La présence d'un pourcentage élevé de particules lamellaires dans les compacts à usage cosmétique les rend difficiles à compacter. La cohésion des particules de poudre n'est rendue possible que par la présence d'un liant de caractère lipophile. La détermination du bilan énergétique de compression ainsi que des mesures de dureté par indentation et de résistance mécanique des compacts mettent en évidence l'importance des propriétés rhéologiques et aussi du pourcentage auquel il est employé pour l'obtention de caractéristiques mécaniques optimales. Il est montré que les compacts cosmétiques de ce type sont un exemple d'un système de poudre humide compactée, différent en celà de ceux rencontrés dans d'autres branches de l'industrie (pharmacie, metallurgie, céramique…). Enfin, ces résultats permettent de conclure qu'une amélioration significative de la formulation passe par une bonne connaissance des propriétés rhéologiques du liant.
Approche osmotique de l'hydratation du stratum corneum
Authors: FORESTIER J. P.
Published: May 2007

Afin de reprendre l'hypothèse selon laquelle l'absorption de l'eau par le stratum corneum est un phénomène osmotique et afin de d'effectuer des études, in vitro, de la biophysique de la diffusion de l'eau par osmose, nous avons mis au point un Modèle Osmotique de Cornéocyte (MOC), qui est constitué par de la kératine isolée par une membrane semi‐perméable.

Immeré dans de l'eau, le MOC voit sa masse augmenter. En effet, bien qu'insoluble, la kératine est hydrophile et en accord avec le Deuxième principe de la thermodynamique, elle fait diffuser par osmose, de l'eau vers l'intérieur du MOC.

A saturation, l'eau absorbée représente 13 fois la masse de kératine.

La diffusion s'effectue selon une cinétique classique: la masse de l'eau qui pénètre est proportionelle à la racine carrée du temps.

Les éléments constitutifs du Facteur Naturel d'Hydratation comme l'urée, l'acide lactique, l'acide pyrrolidone carboxylique, accroissent la vitesse de diffusion et la quantité totale d'eau absorbée. Un humectant comme la glycérine produit un effet semblable. L'urée est le composé qui donne les meilleures performances.

L'accroissement de la vitesse de diffusion par osmose dans le MOC en présence de composés hydratants peut s'interpréter comme un accroissement de l'hydrophilie de la kératine induite par ces composés.

Le MOC semble pouvoir permettre, outre une étude théorique sur le phénomène osmotique dans le stratum corneum, des études préliminaires in vitro des produits hydratants hydrosolubles utilisables en cosmétologie.
Photostability assessment of sunscreens. Benzylidene camphor and dibenzoylmethane derivatives
Authors: DEFLANDRE A. , LANG G.
Published: May 2007

Synopsis

A rapid method has been developed in order to compare the photostability of several sunscreen agents incorporated in the same type of emulsion. Thin films of the different preparations were spread on quartz plates and irradiated with a solar simulator. Differences in energy distribution according to wavelengths observed with solar simulator and sun radiation were taken into account. A kinetic study of absorption properties was carried out under solar simulator irradiation. A simple calculation gave the results which would be obtained under sunlight.

This technique differentiated the reversible transformations of photoisomerizable compounds from an irreversible disappearance which resulted in a significant loss of protective power.

Applied to benzylidene camphor derivatives, this technique showed the excellent photostability of these sunscreen agents.
Silicones: use of substantive properties on skin and hair
Authors: DISAPIO AL , FRIDD PETRINA
Published: May 2007

Silicones have been incorporated in personal care products since the 1950s. Initially used in skin care products, and more recently in hair care applications, silicones are recognized for their lubricating properties and for the characteristic soft smooth feel they impart. With recent advances in silicone technology, these fluids can also provide substantivity and durability.

Resinous silicones such as trimethylsiloxysilicate act as effective substantivity additives when combined with dimethyl silicone in skin care formulations. In tests evaluating the number of wash cycles required to penetrate a silicone barrier, resistance to removal increases markedly as the proportion of resinous silicone to dimethyl silicone is increased. This improvement is related directly to decreased solubility of the resin.
Substantivity of sunscreens—preparation and evaluation of some quaternary ammonium benzophenone derivatives
Authors: SAETTONE M. F. , ALDERIGI C. , GIANNACCINI B. , ANSELMI C. , ROSSETTI M. G. , SCOTTON M. , CERINI R.
Published: May 2007

Synopsis

In continuation of previous studies on keratin‐substantive sunscreens, two series of quaternary ammonium compounds, derived from 2,4‐dihydroxy and from 4‐hydroxybenzophenone and containing O‐alkyl and N‐alkyl chains of different length were prepared and submitted to substantivity tests on wool, to microbiological tests on two bacterial and two fungal species, and to tests for allergenicity/irritation on human skin. All compounds were rapidly adsorbed by wool in aqueous solution: as expected, the maximum amounts adsorbed at equilibrium (Smax), indicative of the skin substantivity, were greatest for the C12 N‐alkyl derivatives, and showed a progressive decrease with increasing length of the N‐alkyl substituent. No substantial substantivity differences were detected in four C12 quaternary derivatives, differing by the presence (or absence) of a 2‐OH group in the benzophenone moiety and by the length of the O‐alkyl (n= 2 or 3) side chain. When tested for antimicrobial activity, however, only the 4‐hydroxybenzophenone C12 quaternary derivatives showed an order of activity comparable with that of two reference compounds. The conditions leading to a maximal antibacterial activity in the present compounds appeared to be the absence of the 2‐OH group, and a shorter O‐alkyl side chain. None of the new quaternary derivatives showed skin‐irritant properties. The results of this investigation, while confirming the peak substantivity of C12 quaternary derivatives, indicate the possibility of dissociating, in a quaternary ammonium sunscreen, the skin substantivity from other unwanted side‐effects, and offer some guidelines for the development of safer agents of this type.
Etude de l'action d'un traitement par voie topique sur la synthèse de la kératine pilaire chez le Rat
Authors: ZAHAF F. , OUSTRIN J.
Published: May 2007

Deux protocoles expérimentaux sur des rats Wistar mǎles prépubères, ont été comparés en étudiant l'influence d'une lotion d'extraits végétaux sur la synthèse de la kératine du poil. Par l'utilisation de la cystéine S‐35 comme précurseur marqué on démontre un effet stimulant de la préparation essayée sur la synthèse de la kératine par les follicules pileux permettant peut‐ětre secondairement une pousse plus active du poil.

Les deux protocoles expérimentaux, avec un ou plusieurs prélèvement de poil chez le měme animal, donnent des résultats comparables et significatifs. L'activité de la lotion est démontrée dès le huitième jour d'application quotidienne, et 24 heures aprés l'ingestion du précurseur marqué avec un maximum en fin de la phase catagène.
Determination of sun protection factors. Correlation between in vivo human studies and an in vitro skin cast method
Authors: FERGUSON J. , BROWN M. W. , HUBBARD A. W. , SHAW M. I.
Published: May 2007

Synopsis

Sun protection factors were determined by both an in vitro method which used resin casts taken from replicas of human skin and by an in vivo SPF method. Thirty‐eight product development samples were tested for the level of sun protection using both methods and the results were compared. The values obtained showed a positive relationship which was closely approximated by a log‐linear regression of in vivo data on in vitro data (regression coefficient, r2= 0.86).

It is concluded that the cast technique is quick, convenient, inexpensive and in its present form useful for screening sunscreen products prior to in vivo SPF testing.
Image analysis as a tool for measuring biological phenomena of the skin
Authors: BARTON S. P. , MARKS R.
Published: May 2007

Synopsis

In an industry very much concerned with image it is not surprising to find that Image Analysers are beginning to fulfil the potential that a few groups recognized some time ago. This presentation will outline briefly the principles of image analysis and demonstrate how these can be put to use in measurement. Skin will be referenced as the example almost throughout this text, though it is important to remember that there are other applications which may interest cosmetic chemists; in the field of particulates and emulsions for example, and generally in production quality control. Finally, since the technology is often very easy to use, potential dangers in its misuse will also be pointed out where necessary.
Evolution of lipid composition in skin treated with blackcurrant seed oil
Authors: BROD J. , TRAITLER H. , STUDER A. , De LACHARRIERE O.
Published: May 2007

Synopsis

This report utilizes a new procedure based on epidermal stripping to analyse unlabelled skin fatty acids. This technique was applied to the study of human dry skin treated with blackcurrant seed oil, an essential fatty acid rich lipid also containing γ linolenic acid.

In human dry skin the usual fatty acids were found in the stratum corneum as in normal skin outer layers. Among the saturated series no significant difference was observed in the C16 chain but a smaller quantity of C18:0 was detected. In the unsaturated series a marked fall of linoleic acid as well as a higher level of C16:1 in the stratum corneum appeared as the major significant events that could characterize dry skin. γ linolenic acid was detectable neither in normal nor in dry skin. α linolenic acid was found but not consistently.

After multiple applications of blackcurrant seed oil in an emulsion preparation, impregnation of the stratum corneum was complete, and essential or other fatty acids contained in the oil (particularly linoleic and linolenic acids) were found in combination with endogenous lipids. Possibly they contribute to enhance the protective effect of the stratum corneum.
Odours, emotion and psychophysiology
Authors: VAN TOLLER S.
Published: May 2007

Synopsis

The basis for the relationship between emotion and olfaction is reviewed and discussed from both the theoretical and experimental approach. Published studies include olfactory memory, human semiochemicals, and olfactory communication between humans. Evidence for the olfactory system being a special emotion sense has not been conclusive. One limitation has been the verbal paucity of subjects in describing smells. This has led to the development of psychophysiological techniques involving the use of subvert bioelectrical signals generated within the body. A number of techniques involving measurement of the electrical activity of the brain are discussed. These involve evoked olfactory potentials (OEP), contingent negative voltage (CNV) and brain electrical activity mapping (BEAM). These new techniques involving the electrical activity of the cortex are helping us to unravel the complexities of olfaction and emotion.
In vivo transepidermal water loss and skin surface hydration in assessment of moisturization and soap effects
Authors: WILSON D. , BERARDESCA E. , MAIBACH H. I.
Published: May 2007

Synopsis

Transepidermal water loss (TEWL), skin surface water loss (SSWL) and water content of the stratum corneum are utilized to assess the hydration effects of moisturizers and soaps. The relationship among these parameters may help differentiating hydration obtained via occlusion or by water‐holding in the stratum corneum. Furthermore, skin function (hydration, dehydration, barrier damage) can be studied comparing the data obtained with these techniques. In this study, the effects of glycerol, petrolatum, soaps and commercial moisturizers on the skin are investigated and discussed.
The behaviour of cationic cellulose derivatives containing fatty quat groups
Authors: JONES R. T. , BROWN C. A.
Published: May 2007

The use of trimethyl quat cellulose derivatives in hair and skin care products is well established. The introduction of fatty quat groups into cellulose can modify the surface activity and conditioning behaviour. The present study was directed to a coconyl dimethyl quat derivative of cellulose, with an average molecular weight of approximately 100,000. A modified version of the rubine dye test, capable of giving quantitative results, was used to seek information on substantivity and tendency for build‐up on hair. The evidence presented indicates that this surface‐active cellulose polymer exhibits a plateau maximum value for substantivity which is achieved by a single conditioning treatment as an aqueous solution with a concentration of 1% or higher. The same plateau value can be approached by successive shampoo/conditioning cycles at lower polymer concentrations. This in‐built mechanism for preventing excessive build‐up from aqueous solutions is compared with the behaviour of other cationic cellulose polymers of higher average molecular weight.
Chemical stability and microbiological reply of preservative systems in cosmetics: a direct correlation
Authors: BENASSI C. A. , RETTORE A. , SEMENZATO A. , BETTERO A. , CERINI R.
Published: May 2007

Synopsis

The results of a chemical/microbiological comparative study on different preservative mixtures are reported. The aim of the investigation was to ascertain whether there was a correlation between chemical stability and microbiological activity.

The studies were carried out directly in cosmetic emulsions preserved with different mixtures of Prevan, Bronopol, Germall 115 and Kathon CG.

The degree of microbiological activity was tested with respect to E. coli, Ps. aeruginosa, Asp. niger, S. aureus using the agar diffusion test, over a period of 400 days.

The chemical behaviour of the different mixtures was evaluated by HPLC in reverse phase mode. The emulsion samples were directly injected after dilution with a THF/H2O) (9/1) solvent mixture.
In vitro studies on the effect of linear alkyl benzene sulphonate on serum albumin
Authors: JAVED SEEMA , MISRA VIRENDRA , VISWANATHAN P. N.
Published: May 2007

Synopsis

Linear alkyl benzene sulphonate was found to influence the thermal and fluorescence profile of serum albumin in vitro, indicating the possibility of protein‐detergent interaction in the skin irritancy of detergents.
Screening tests of free radical scavengers for preventing sun‐accelerated cutaneous ageing
Authors: BONNE C. , MULLER A. , GREGOIRE C. , SINCHOLLE D.
Published: May 2007

Synopsis

Free radical formation has been shown to occur in UV‐irradiated skin and a large body of evidence suggests that these reactive agents are responsible for sun‐accelerated cutaneous ageing. The paper describes two tests for screening free radical scavengers potentially capable of inhibiting photo‐induced skin alterations. They are based on analysis of thiobarbituric acid‐reactive materials either in an acellular model in vitro or in the epidermis of rose bengal‐sensitized mice after white light irradiation. The tests were illustrated with silymarin, a potent vegetable free radical scavenger.
Action of skin penetration enhancers—the Lipid Protein Partitioning theory
Authors: BARRY B. W.
Published: May 2007

Synopsis

Skin penetration enhancers reversibly decrease the barrier resistance of the stratum corneum and allow drugs to penetrate more readily to the viable tissues and the systemic circulation. This paper presents a general theory for accelerant activity based on possible alterations at the molecular level of the components of the horny layer. Within the intercellular route, enhancers may interact at the polar head groups of the lipids, within aqueous regions between lipid head groups, and between the lipophilic tails of the bilayer. Inside the corneocyte it is the keratin fibrils and their associated water that are the targets. High concentrations of solvents may also alter partitioning processes. Because of the involvement of lipid and protein modifications, together with partitioning phenomena, the scheme of possible enhancer interactions has been termed the Lipid Protein Partitioning (LPP) theory. This theory is applied specifically to water, Azone, dimethylsulphoxide, dimethylformamide, 2–pyrrolidone, N‐methyl‐2–pyrrolidone, oleic acid, decylmethylsulphoxide, sodium lauryl sulphate and propylene glycol.
Ageing and free radical formation. A biochemical approach to evaluate the efficacy of cosmetic preparations
Authors: MIGNINI E. , GIANI P. , LANGLOIS G. C. M. , PANTAROTTO C.
Published: May 2007

Synopsis

A new method is described for studying the in vivo formation of oxygen reactive species (free radicals) in humans after exposure to UV radiation. The procedure is based on the quantitative determination in urine of (i) metabolic products of pentane, a hydrocarbon formed during lipid peroxidation, and (ii) thymine hydroxylated bases and deoxyribonucleosides as indices of DNA repair that has taken place. Creams containing UV filters protect the organism against free radical formation. Subjects using such cosmetic preparations during complete body tanning sessions do, in fact, have reduced urinary excretion of 2‐pentanol and hydroxythmine derivatives.
Acetylene‐derived polymers and their applications in hair and skin care
Authors: PETTER P. J.
Published: May 2007

Synopsis

Since the introduction over 30 years ago of polyvinylpyrrolidone (PVP) as the first synthetic hairspray resin, acetylene‐derived polymers have found wide and increasing applications in the cosmetics and toiletries industry. This review covers the two main classes of acetylenic polymers. In the first class, in which the chemistry may be traced back to reaction of acetylene with formaldehyde, are included PVP homopolymers and copolymers of VP with vinyl acetate, dimethylaminoethyl methacrylate, vinylcaprolactam and styrene. In the second class, stemming from reaction of acetylene with methanol, are the poly (vinyl methyl ether/maleic acid) monoester resins.
Non‐invasive assessment of stratum corneum structure and function
Authors: MARKS R. , EDWARDS C. , BLACK D.
Published: May 2007

Synopsis

Methods for the study of the stratum corneum in situ are described and their application to clinical problems and cosmetic science are discussed. In vivo measurements of the thickness of skin and the components of skin can be made using high frequency pulsed ultrasound. Improved resolution of the device should allow measurement of epidermal thickness, and even that of the stratum corneum, which may vary with hydration.

The protective ability of the stratum corneum can be estimated in a number of ways, the most familiar technique being transepidermal water loss measurements. Mechanical properties of the stratum corneum have been widely investigated in vivo by numerous researchers. A recent technique devised by us to deform the stratum corneum using an extendable metal frame has been used on patients with ichthyotic disorders. The deformation or compliance of the skin surface has been measured using profilometric methods, and compared to normal individuals. The results appear to be in agreement with the loss of flexural ability experienced by ichthyotic patients.

Other mechanical methods more usually involve the measurement of the forces generated by skin while undergoing extension. Three techniques are described which have been used to investigate hydrational change with emollient application.

Finally, the phenomenon of desquamation is discussed and methods presented for its evaluation. Passive collection of corneocytes using chambers is useful for estimation of the rates of desquamation, but are laborious and inconvenient. Forced desquamation using the desquamator enables rapid controlled harvesting of corneocytes. In addition to this, the dansyl chloride fluorescence technique has been adopted for estimation of stratum corneum kinetics using visual comparison and fluorimetric techniques.

These techniques require further refinement and validation, but the tests available now are nonetheless important in understanding the biology and pharmacology of the stratum corneum.
The measurement of hair colour
Authors: GERRARD W. A.
Published: May 2007

The colour of the hair of 65 subjects was measured using a Minolta Chromameter model CR200. Readings were taken by holding the unit against the back of the subject's head, and recorded using the L*a*b* system of colour co‐ordinates.

All subjects had hair in which yellow and red (rather than blue or green) dominated. The lightness (L*) of all hair fell in the range 17–67, the redness (a*) in the range 0–6 and the yellowness (b*) 0–20. These limits can be seen as effectively outlining the range of colours which can be said to be natural.

The chromameter gave rapid and reproducible results on hair in situ and was easy to use. The method should be of use to those who wish to quantify the effects brought about by bleaching or dyeing formulations.
Progressive evaluation of skin irritancy of cosmetics using human volunteers
Authors: JENKINS H. L. , ADAMS M. G.
Published: May 2007

Synopsis

Cosmetics and toiletries should not elicit adverse reactions in use. Neither should they cause unacceptable effects if mis‐used. Reliable prediction of these product attributes can be achieved by subjecting human volunteers to typical product exposure and to grossly exaggerated exposure. However, to ensure that volunteers do not sustain harmful effects there needs to be a cautiously progressive programme of testing.

There must be adequate data on record to support exposure of human skin to the test material. The first contact with human skin should be in a small area, for short duration, and be very closely observed. When the effects are well within acceptable limits the exposure can be extended. As information accumulates, the application procedure can evolve towards simulation of the intended use of the product under controlled conditions, and eventual free use in consumer tests; and also towards exaggerated use to evaluate potential irritancy, using exaggerated frequency of use, exaggerated product concentration, or occlusive cover to promote skin penetration and enhance irritancy.

Skin reactions under exaggerated exposure conditions do not necessarily mean that a product would be unacceptable under normal use conditions or when misused predictably. Therefore, appropriate standard products must be included in tests to provide relevant comparison when significant skin reaction does occur.

Data will be presented to demonstrate progressive evaluation of irritancy of cosmetics and toiletries, based on expert assessment of visible skin reactions and on analysis of spontaneous and prompted comments about subjective effects, and including appropriate attention to the ethical requirements for tests involving human volunteers.
New oil‐gelling agents for cosmetics: formation mechanism of oil gels
Authors: FUKASAWA JUN‐ICHI , TSUTSUMI HISAO , ISHIDA ATSUO
Published: May 2007

New oil‐gelling agents have been developed composed of a long‐chain dialkyl phosphate (DP) surfactant and aluminium ion or multinuclear aluminum ion (MAI) which provide good oil‐gel systems. One such gelling agent is the aluminum salt of DP (DP‐Al) prepared as a precipitate by mixing DP with aluminum chloride in aqueous solutions. Addition of small amounts of the salt to non‐polar oils led to hardening of the oil solutions at temperature below the melting point of the alkyl chain (Tc) of DP‐Al. Results obtained by X‐ray diffraction techniques and with scanning electron microscopy (SEM) revealed that linearly‐polymerized assemblies of DP‐Al expand in oils three‐dimensionally, which suggests that the excellent stability of the gel systems arises from the highly ordered structure. The gelling agent of DP‐Al offered the ideal rheological property to waxy cosmetic products such as lipsticks. The complexes of DP with MAI particles (1 nm diameter) of aluminum chlorohydrate, Al13O4(OH)24(H2O)12CI7, provided the ideal thixotropic behaviour in non‐polar oils. The DP‐MAI particle complexes were found to interact weakly by cohesive forces which makes a highly ordered structure of the DP‐MAI particle complexes. The DP‐MAI particle complexes gave excellent stability and transparency to cosmetic products such as w/o creams.
Assessment of surfactant cytotoxicity: comparison with the Draize eye test
Authors: TACHON P. , COTOVIO J. , DOSSOU K. G. , PRUNIERAS M.
Published: May 2007

Synopsis

We have compared the in vitro cellular toxicity and the in vivo ocular irritation potency of 16 surfactants (7 non ionics, 3 anionics, 2 amphoterics, 4 cationics) ranking from very weakly irritant to strongly irritant. In vitro, the cellular toxicity was estimated on Chinese hamster lung fibroblasts (V79) using a cell mortality test and a cell growth inhibition test. For each surfactant, a lethal concentration 50% without foetal calf serum (LC.50–0) and with 10% foetal calf serum (LC50–I0), as well as the concentration required to reduce 50% of the growth (CI.50) were determined. In vivo, each surfactant was applied directly to the cornea of six albino rabbits. The maximal ocular irritation score (I0 max) and the ocular irritation score obtained seven days later (I0 J7) were collected. Comparison of in vitro results with those obtained in vivo showed good correlations, particularly when I0 max and the difference (LC.50–10 ‐ LC50–0) were considered (r= 0.845, P<0.001). These results suggest that the use of cell culture tests as pre‐screening systems to appreciate eye irritation potency of surfactants could be a reliable alternative method in order to reduce the use of the Draize rabbit eye test. They can provide a better knowledge of the irritative process induced by surfactants (cellular toxicity and protein interaction potency).
Pitfalls in the in vitro determination of sunscreen protection factors using broad band ultraviolet radiation detectors and solar simulating radiation
Authors: DIFFEY B. L.
Published: May 2007

Synopsis

Reliable in vitro techniques for assessing sunscreen protection factors have relied upon obtaining the forward scattering transmission spectrum of the test compound applied to a suitable substrate such as mouse or human epidermis. A theoretical analysis of alternative techniques using broad‐band ultraviolet radiation detectors in conjunction with a source of simulated sunlight shows that the method is likely to yield unreliable values of sun protection factors and the reasons for this are discussed.
Activity of capryloyl collagenic acid against bacteria involved in acne
Authors: FOURNIAT J. , BOURLIOUX P.
Published: May 2007

Synopsis

Capryloyl collagenic acid (Lipacide C8Co) has similar bacteriostatic activity in vitro to that of benzoyl peroxide towards the bacteria found in acne lesions (Staphylococcus aureus, Staphylococcus epidermidis and Propionibacterium acnes) (MIC between 1 and 4 mg ml−1 for C8Co, and between 0.5 and 5 mg ml−1 for benzoyl peroxide). The presence of Emulgine M8 did not affect the bacteriostatic activity of C8Co. A 4% w/v solution of C8Co (incorporating Emulgine M8) fulfilled the criteria for an antiseptic preparation as laid down by the French Pharmacopoeia (10th Edition), and had a spectrum 5 bactericidal activity according to the French Standard AFNOR NF T 72–151. The excellent cutaneous tolerance of capryloyl collagenic acid would indicate that an aqueous solution might be of value for topical treatment of the bacterial component of acne.
Use and properties of perfluoropolymethyl‐isopropylethers in skin and hair cleaning; system stabilization and interference with sebum redistribution on skin and hair
Authors: RIGANO L. , SAVONELLI S. , BENCINI P. L.
Published: May 2007

Synopsis

Perfluoro‐polymethyl‐isopropyl ethers (PPIE) are known for their low surface tension and spreading characteristics. Their use in detergent systems was difficult because of their insolubility in most fluids (except fluorinated ones), but microdispersions have been obtained with surfactant blends, the compositions of which minimize the interfacial tension. Thickeners have been tried in order to improve suspension stability during shelf life. Spreading of PPIE has been studied by using in vivo and in vitro evaluations, both on hair and on skin. Results are discussed, as these systems could improve greasy skin conditions and decrease the rebound effect.
Modèle mathématique pour l'étude des équilibres physico‐chimiques de permanentes
Authors: CHIODI F.
Published: May 2007

La plupart des permanentes du commerce sont constituées d'acide thioglycolique (éventuellement associéà l'acide thiolactique), neutralisé par l'ammoniac, elles sont additionnées de carbonate d'ammonium comme tampon. Le système peut ětre traité comme la neutralisation d'un mélange d'acides thioglycolique et carbonique par l'ammoniac, et il est complètement défini par trois paramètres, trois concentrations, ou deux concentrations et le pH, ou trois paramètres analytiques indépendants. Les calculs théoriques de l'équilibre sont compliqués du fait qu'il s'agit de l'équilibre de deux diacides faibles neutralisés par une base faible. Un modèle mathématique développé exclusivement par des équations théoriques permet l'interprétation des équilibres et la réalisation des calculs fiable pour la préparation des formules remplissant certaines caractéristiques. Le modèle permet de réaliser facilement des simulations en faisant varier les concentrations, les acides (par la voie des constantes de dissociation) ou d'associer différents acids et/ou bases organiques ou minérales. Une application complémentaire du modèle est de tracer la courbe dérivée à la courbe de neutralisation et de cette façon mesurer l'effet tampon en différents points par la mesure de sa pente.
Rheological behaviour of ‘Cérat Cosmétique, Ph. F.’
Authors: SELLÉS E. , JIMÉNEZ I. , FRESNO M.
Published: May 2007

Synopsis

Rheological analysis during the preparation of dermocosmetic products allows the deduction of properties related to consistency and fluidity, which are very important for cream application. This paper rheologically examines a cold‐cream formula, ‘Cérat Cosmétique’ from the French Pharmacopoeia. ‘Cérate’, or cold‐cream, is one of the most ancient cosmetic preparations.

The Rheotest 2 viscometer, which was used for experimental determinations, allowed the rheograms to be plotted and the characteristic rheological constants to be calculated. On the basis of this information, the preparation under study was seen to present plastic behaviour. However, posterior thixotropic studies indicated that ‘Cérat Cosmétique, Ph. F.’ had no true thixotropic behaviour.
Reactivity of hair cystine in microemulsion media
Authors: ERRA P. , SOLANS C. , AZEMAR N. , PARRA J. L. , TOURAUD D. , CLAUSSE M.
Published: May 2007

Synopsis

Reduction of keratin cystine by thioglycolic acid incorporated in microemulsions of the water/sodium dodecilsulphate/n‐pentanol/n‐dodecane system has been determined. The results obtained have been interpreted in relation to the properties of the reaction media. Microemulsions with constant oil‐to‐surface active mixture weight ratios (Ro/s) and different concentrations of water were chosen as reaction media. At low water concentrations a steep increase in reactivity with the increase of water was observed at all values of Ro/s. However it was more pronounced the higher the oil content. A relation between maximum cysteine formation and percolative behaviour of the microemulsion was found at high Ro/s values.
Sensitivity to perfumes and preservatives in patients with contact dermatitis
Authors: KINTZIOU H. , PAPAIOANNOU G. , RALLIS M.
Published: May 2007

Synopsis

Patients with contact dermatitis were patch tested for sensitivity to perfumes (perfume mixture, balsam of Peru) and to preservatives (formaldehyde). The percentages of sensitivity in Greek patients with contact dermatitis were 8.1% for the perfume mixture, 3.7% for the balsam of Peru and 2.3% for formaldehyde. It is notable that 1.4% of the patients demonstrated simultaneous sensitivity to the perfume mixture and to balsam of Peru, while no case of simultaneous sensitivity occurred for formaldehyde and the two other compounds. Factors such as sex, age, occupation and anatomic site of the appearance of dermatitis in patients were taken into account and related to the percentages of sensitivity.

Comparing with the literature we have concluded that the frequency of appearance of sensitivity by Greek patients is not significantly different from the average observed for patients in Northern or Southern Europe.
Studies of factors affecting light scattering by individual human hair fibres
Authors: BUSTARD H.K. , SMITH R.W.
Published: May 2007

Synopsis

An automated goniophotometer has been built to investigate the scattering of light by different types of singly mounted human hair fibres using white light and laser illumination. The effects that varying hair colour and treatment (gold coating, ultraviolet irradiation and dyeing) have on the specular reflectance and on the half‐peak‐height width (ω) have been studied. The polarization of light has been used to discriminate between light reflected from the front surface and light scattered internally by the hair. It has been found that the analysis of results from individual hair fibres has been useful in understanding the light scattering mechanisms which occur in human hair.
Direct contact membrane method for evaluating preservative efficacy in solid cosmetics
Authors: TRAN A.T. , HITCHINS A.D. , COLLIER S.W.
Published: May 2007

Synopsis

A method was developed for evaluating in‐product preservative efficacy of solid cosmetics. Microbes (105–106 colony‐forming units) resting on membrane filters were placed in direct contact with the surface of pressed eye shadows at room temperature in a moist chamber. At daily intervals, or as appropriate, the filters were removed and viable counts were determined by pour plates of modified letheen agar. Linear regression analysis was used to evaluate preservative efficacy. Decimal reduction times (D values) of 1.2–1.7 days were obtained for Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 8739 on in‐house pressed eye shadows preserved with parabens and Germall 115. An average D value of 1.7 was also obtained for P. aeruginosa and S. aureus on a commercially pressed eye shadow containing the same preservatives as the in‐house formulation. However, this commercial product was either totally ineffective or about 3–6 times less effective against E. coli. The predicted complete inactivation time corresponding to the above D value was about 9 days and was within the limits of current cosmetic guidelines for bacteria of ‘less than 0.1% survival by the 14th day.’
The skin microflora and the formation of human axillary odour
Authors: RENNIE P.J. , GOWER D.B. , HOLLAND K.T. , MALLET A.I. , WATKINS W.J.
Published: May 2007

Synopsis

We have examined the relationship between human axillary skin microflora and underarm odour (UAO), in particular, the ability of cutaneous bacteria to transform steroids. A study was made of bacterial population density and odour intensity of the axillae of 34 normal male subjects. There was a statistically significant association between population density of aerobic coryneform bacteria and UAO intensity. No associations could be found between population densities of staphylococci, micrococci or propionibacteria and UAO intensity. An in vitro model for formation of UAO was developed, and used to test individual bacterial isolates. Only aerobic coryneforms could produce axillary odour in vitro, most notably C. xerosis. Many aerobic coryneforms could transform testosterone, the principal metabolites being 5α‐ and 5β‐DHT, androstenedione, and 5α‐ and 5β‐androstanedione. UAO positive coryneforms were more metabolically active than UAO negative bacteria. Micrococci also transformed testosterone to androstenedione, whilst staphylococci and propionibacteria could not metabolize it. A hypothesis for the role of aerobic coryneforms in the formation of human axillary odour is discussed.
Measurement of beard hair removal efficacy using image analysis
Authors: BREUER M.M. , ACKERMAN C.S. , POZZI S. , SNEATH R.
Published: May 2007

Synopsis

Using an image analyzer, a method was developed for measuring differences in the beard hair removal efficacy of shaving systems. The method involves the collection of shaved whiskers from three panels of shavers. The panelists use two different shaving products on the two sides of their faces which they alternate from day to day. The lengths or projection areas of about 200 whiskers from each shave is then measured using an electronic image analyzer. By comparing the mean values of the whisker lengths (areas), differences in hair removal efficacies less than 1% can be measured at statistically significant levels. The protocol allows the determination of differences in both the first and second cuts of hair lengths, when twin bladed razors are used.
Influence of hazelnut oil phospholipids on the skin moisturizing effect of a cosmetic emulsion
Authors: MASSON P. , MEROT F. , BARDOT J.
Published: May 2007

Synopsis

Previous studies have shown significant differences between the moisturizing effects and skin tolerances of virgin and refined vegetable oils when incorporated in cosmetic emulsions. They have also shown significantly greater and longer lasting moisturizing potential for a cosmetic emulsion containing virgin vegetable oils when compared with refined oils in the same emulsion. Results were obtained with sweet almond and hazelnut oils. Hazelnut oil has now been analysed to show the effect of refining. The phospholipid content of the oil decreased from 286 ppm in virgin oil to traces in refined oil.

These oils were added at 10% to a cosmetic emulsion applied twice a day for 28 days to the skin of 56 volunteers and the changes in moisturizing effect measured by means of the capacitance method (corneometer CM 240 Khazaka). Measurements were made under conditions of controlled temperature and humidity on the first day of application and repeated after 21 and 28 days of treatment. A significant increase in the moisturizing effect of the emulsion containing virgin hazelnut oil was found and this was itself significantly greater than the emulsion containing refined oil. Both emulsions had a greater moisturizing effect when compared with the control emulsion and the untreated skin.

Phospholipids were isolated by dialysis from virgin oil and added to the refined oil (234 ppm). The moisturizing effect obtained with the emulsion containing the enriched refined oil was shown to be the same as that obtained with the virgin oil emulsion.
Preliminary Communication: Treatment of irritant contact dermatitis in workmen with perfluoropolymethylisopropyl ether (Fomblin HC)
Authors: PANTINI G. , FORESTIERI R. , BRUNETTA F. , BENCINI P. L.
Published: May 2007

Synopsis

Non‐allergic contact dermatitis is a major dermatological problem for the workmen of an important factory which manufactures industrial machines (SAIMP SpA) located at Padua. Such dermatitis is due to the presence in the environment of paints, solvents, surfactants, lubricants and metal powders (steel and cast‐iron). As medical treatment, the factory doctor practises the use of common barrier creams which do not give completely satisfactory results. To cope with this problem, some workmen were treated with preparations containing Fomblin HC.

The highly successful results of this new type of treatment are reported: among other findings this study shows, through experimental evidence, that Fomblin HC has a protective effect not only against water soluble substances but also against oil soluble substances (in fact, the latter are probably the main cause of contact dermatitis contracted by these workmen).