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Showing papers in "Journal of Cosmetic Science in 2002"


Journal Article
TL;DR: Cyclodextrins are non-toxic cyclic polysaccharides that form inlusion complexes with numerous organic molecules and can be used for the formulation of cosmetic products.
Abstract: Cyclodextrins are non-toxic cyclic polysaccharides. They form inlusion complexes with numerous organic molecules. The physical and chemical properties of the guest molecules change due to complex formation. Thus, for example, the stability of the complexed molecule against light and oxygen increases and the vapor pressure is reduced. The solubility of slightly soluble molecules increases in a cyclodextrin complex. All these and further advantages of cyclodextrins and their complexes can be used for the formulation of cosmetic products. As a result, effects are possible not realizable with common techniques.

234 citations


Journal Article
TL;DR: From the results obtained in in vitro and in vivo tests, LECS showed a significant antioxidant effect and some flavonols (kaempferol and quercetin derivatives) and hydroxycinnamic acids (caffeic acid, ferulic acid, p-cumaric Acid, and cinnamic acid).
Abstract: The aim of the present study was to evaluate the in vitro antioxidant and in vivo photoprotective activities of a lyophilized extract of Capparis spinosa L. (LECS) obtained by methanolic extraction from the flowering buds of this plant. For the in vitro experiments, LECS was tested employing three different models: (a). bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test); (b). peroxidation, induced by the water-soluble radical initiator 2,2'-azobis(2-amidinopropane) hydrochloride, of mixed dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles (LUVs) (LP-LUV test); and (c). UV-induced peroxidation of phosphatidylcholine multilamellar vesicles (UV-IP test). The in vivo antioxidant/radical scavenger activity was assessed by determining the ability of topically applied LECS to reduce UVB-induced skin erythema in healthy human volunteers. From the results obtained in in vitro and in vivo tests, LECS showed a significant antioxidant effect. Furthermore, by chromatographic fractionation and spectroscopic methods, we identified the major constituents of LECS, and particularly some flavonols (kaempferol and quercetin derivatives) and hydroxycinnamic acids (caffeic acid, ferulic acid, p-cumaric acid, and cinnamic acid).

111 citations


Journal Article
TL;DR: The results suggest that the Fucus vesiculosus extract possesses anti-aging activities and should be useful for a variety of cosmetics.
Abstract: Recently the researchers found that an extract of Fucus vesiculosus, which is a type of seaweed, promotes the contraction of fibroblast-populated collagen gels through increased expression of integrin molecules. In this study, they investigated the effects of topical application of an aqueous extract of this alga on the thickness and the mechanical properties of human skin. A gel formulation that included 1% of the extract was applied topically to human cheek skin twice daily for five weeks. A significant decrease in skin thickness measured by B-mode ultrasound was elicited, as was a significant improvement in elasticity measured with a Cutometer as compared with controls. In cheek skin, the thickness normally increases and the elasticity usually decreases with age. These results suggest that the Fucus vesiculosus extract possesses anti-aging activities and should be useful for a variety of cosmetics.

61 citations


Journal Article
TL;DR: The jewelry powders (fine powdered jade and tourmaline powders) were screened by far-infrared rays for radiation properties and tested for the effects of far- Infrared rays on the human skin by temperature observation using an infrared thermal analyzer.
Abstract: Far-infrared rays have certain kinds of effects on the human body, especially on skin, blood circulation, and skin cell vitalizing. Some jewelry powders radiate far-infrared rays. Jade has powerful far-infrared ray radiation, and tourmaline has pyroelectric and piezoelectric properties and radiated far-infrared rays. The jewelry powders (fine powdered jade and tourmaline powders) were screened by far-infrared rays for radiation properties and tested for the effects of far-infrared rays on the human skin by temperature observation using an infrared thermal analyzer.

55 citations



Journal Article
TL;DR: Results indicated that phosphatidylcholine could act as a penetration enhancer, irrespective of its presence in vesicular form or solubilized form.
Abstract: Phospholipids or liposomes are recognized to have skin permeation enhancing ability, although their mechanisms are still controversial. The aim of this study was to establish a method of increasing the skin permeation of active ingredients, using phosphatidylcholine as a permeation enhancer. Caffeine was used as a model active ingredient and in vitro skin penetration experiments were performed using Franz-type diffusion cells to determine the amount of absorbed caffeine. Lipid vesicles were prepared by the microfluidization process. The encapsulation efficiency of caffeine was found to be very low due to the instability of the liposome structure and the water solubility of caffeine. However, the amount of absorbed caffeine was nearly independent of the encapsulation efficiency and the vesicle size, but increased with the increase of phosphatidylcholine concentration. These results indicated that phosphatidylcholine could act as a penetration enhancer, irrespective of its presence in vesicular form or solubilized form.

38 citations


Journal Article
TL;DR: It was found that the pores in the medulla can be generated in a heat-drying process, and the decreases in contrast caused a whitish and lusterless appearance.
Abstract: In this study the influence of the medulla structure on hair appearance was examined. Hair with a porous medulla gave a whitish and lusterless appearance because of light scattering from the fiber center, whereas in the cases without pores, a clear and brilliant appearance was observed. The optical influences of the medulla pores were measured by a spectral goniophotometer, and obtained data were analyzed in terms of the CIE L*a*b* color system. Both contrasts in lightness and apparent color (chroma and hue) decreased in the hair with medulla pores, and the decreases in contrast caused a whitish and lusterless appearance. The distribution of the amount of medulla pores was investigated for Japanese females. The histogram was further analyzed by hair care behavior of individual panelists, and it was found that the pores in the medulla can be generated in a heat-drying process.

38 citations


Journal Article
TL;DR: The aim of the present investigation is to provide an alternative tool for the estimation of SPF values using a calculation based on the UV spectroscopic properties of the individual UV absorbers using a step film model.
Abstract: Measurements of in vitro sun protection factors (SPFs) are a common way of assessing sunscreen formulations at the stage of screening. The aim of the present investigation is to provide an alternative tool for the estimation of SPF values using a calculation based on the UV spectroscopic properties of the individual UV absorbers. As with in vitro measurements, the crucial step is to work out realistic values of transmissions of UV light through a film of the sunscreen formulation in the important spectral range between 290 and 400 nm. Once these transmissions are given, the SPF can be calculated. Since the human skin is an inhomogeneous substrate, a step film model for the calculation of such transmissions had been proposed by J.J. O'Neill. The step film geometry in this model is a function of two parameters that characterize the fraction of the thin and thick parts of the film and their difference in thickness. The transmissions and therefore the SPF are sensitive functions of the step film parameters. In order to use the model for the prediction of realistic SPF values, the step film parameters are calibrated using three sunscreen standard formulations with well-known in vivo SPF. A satisfactory correlation of in vivo SPF values and SPF values calculated with the calibrated step film model using an additional 36 different sunscreen formulations (in vivo SPF values between 3 and 36) is demonstrated.

37 citations


Journal Article
TL;DR: DSC in water is an especially suitable method to determine the kinetics of damage formation in human hair resulting from cosmetic treatments, with apparent first-order kinetics with respect to the number of treatments as well as treatment time.
Abstract: By applying differential scanning calorimetry (DSC) on human hair in water, the thermal stability of hair' major morphological components is determined. Against the background of the two-phase model for alpha-keratins, these components are identified as the partially helical, fibrous intermediate filaments (IF) and the intermediate filament associated-proteins (IFAP) as a cross-linked, amorphous matrix. DSC yields the denaturation enthalpy deltaH(D), which depends on the amount and structural integrity of the alpha-helical material, and the temperature T(D), which is kinetically controlled by the cross-link density of the matrix. To assess the effects of cosmetic treatments, hairs were investigated that had undergone either multiple bleaching or perm-waving treatments. The respective dependencies between denaturation temperature and enthalpy show that both morphological components are similarly affected by bleaching, while reductive damage, in comparison, is more pronounced in the IFs. For both types of treatments, changes in enthalpy follow apparent first-order kinetics with respect to the number of treatments as well as treatment time (perm-waving), yielding characteristic reaction rate constants. It appears that DSC in water is an especially suitable method to determine the kinetics of damage formation in human hair resulting from cosmetic treatments.

36 citations


Journal Article
TL;DR: The use of SE vaginal moisturizer resulted in significantly less vaginal residue compared to Rp vaginal moisturizing, based on polycarbophil, and in comparable relief of vaginal dryness, which strongly suggest that bioadhesion is not important in vaginal moisturizers.
Abstract: This study was designed to compare the vaginal deposition and moisturization of two vaginal moisturizers, Summer's Eve (SE), based on pectin, and Replens (Rp), based on polycarbophil, in a double-blind crossover study design. Fifty-one female patients were each randomly assigned to one of two treatment groups. After a one-week washout period, the products were used for two weeks. After another one-week washout period, product assignments were switched. Colposcopy examinations were performed at the beginning and at the end of each product use. Of the forty-seven patients completing the study, 41 (87%) were found to have no vaginal residue after SE vaginal moisturizer, while only 25 (53%) were found to have no vaginal residue after using Rp vaginal moisturizer. No difference in relief of vaginal dryness or in product acceptance was found between the two products. This study shows that the use of SE vaginal moisturizer, based on pectin, resulted in significantly less vaginal residue compared to Rp vaginal moisturizer, based on polycarbophil, and in comparable relief of vaginal dryness. These results strongly suggest that bioadhesion is not important in vaginal moisturizers.

33 citations


Journal Article
TL;DR: It was found that DSC may be used to identify vehicles that are miscible with sebum and that may deliver drugs preferentially to the sebaceous follicle using differential scanning calorimetry (DSC).
Abstract: It is hypothesized that vehicles that are miscible with sebum may concentrate drugs in the sebaceous follicle. This is important for the treatment of diseases like alopecia and acne. The main objective of the study was to identify different vehicles that affect the thermal behavior of sebum using differential scanning calorimetry (DSC). For this purpose, a model sebum mixture was prepared based on a composition reported in the literature. The test vehicle was added in a concentration of 15% of the weight of the sebum. Small portions of the above mixture were put in a pre-weighed DSC pan. These were run from -50 to 100 degrees C at 5 degrees C/minute. In the model sebum, four distinct transitions were observed: Mp-1 and Mp-2 occurred below 0 degrees C while Mp-3 and Mp-4 occurred above 30 degrees C. Vehicles that affected Mp-3 and Mp-4 were considered for further analysis. From the vehicles tested it was found that the hydrophobic materials were more effective in lowering Mp-3, while the ones that affected Mp-4 did not show any particular trend. Some of the vehicles tested are known skin permeation enhancers, and it is proposed that they interact with sebum and increase permeation by the follicular route. It was found that DSC may be used to identify vehicles that are miscible with sebum and that may deliver drugs preferentially to the sebaceous follicle.

Journal Article
TL;DR: It is demonstrated that the amount of soluble proteins internally formed in permed and bleached hair, labile proteins, is a useful index for hair damage assessment and suggests that a portion of the stable proteins in normal hair was transformed intolabile proteins upon permanent waving and bleaching treatments.
Abstract: We previously found that certain hair proteins were soluble by means of a partial extraction method. In this study, we demonstrate that the amount of soluble proteins internally formed in permed and bleached hair, labile proteins, is a useful index for hair damage assessment. Compared to tensile property changes, this index rose in widely dynamic ranges as the time of either permanent waving or bleaching treatments increased. The amount of labile proteins was much larger than that of proteins eluted into perming and bleaching lotions. However, the labile proteins showed electrophoretic profiles similar to those of the eluted proteins. These results suggest that a portion of the stable proteins in normal hair was transformed into labile proteins upon permanent waving and bleaching treatments. Consequently, permed and bleached hair tends to release the resultant labile proteins.

Journal Article
TL;DR: The elasticity and flexibility of virgin and polymer-treated hair fiber assemblies were investigated by employing straight hair tresses or hair shaped into omega loops, andUntreated hair was found to be almost perfectly elastic and flexible at 50% RH, evident by the linear dependence of force vs deformation.
Abstract: The elasticity and flexibility of virgin and polymer-treated hair fiber assemblies were investigated by employing straight hair tresses or hair shaped into omega loops. Polymer treatment was accomplished by saturating fibers with polymeric solutions, resulting in a deposition of 10-90 mg of polymer per gram of hair. The mechanical testing procedure consisted of subjecting omega-loop-shaped hair or straight hair tresses to multiple bending deformations at 25% strain in a texture analyzer. A total of ten deformations were typically carried out, and elasticity or flexibility parameters were evaluated from data such as (a). the force at 8% deformation, i.e., within the elastic region of bending deformation for hair shaped into an omega loop, (b). maximum force in the first (F(1)) and tenth (F(10)) deformation cycles, (c). elastic modulus in the first (E(1)) and tenth (E(10)) deformation cycles, and (d). the change in hair sample dimensions between the first (H(1)) and tenth (H(10)) deformation cycles. Parameters such as stiffness ratio (1), F(10)/F(1), E(10)/E(1), and H(10)/H(1) were employed to characterize hair tress rigidity, flexibility or resistance to breakage, and plasticity. Untreated hair was found to be almost perfectly elastic and flexible at 50% RH, evident by the linear dependence of force vs deformation. Flexibility parameters F(10)/F(1), E(10)/E(1), and H(10)/H(1) were in the range of 0.95 to 1.0 at low humidity, while the parameters F(10)/F(1) and E(10)/E(1) and were 10% lower at 90% RH. Examination of polymer-modified hair allowed for classification of treatments into categories termed brittle, quite flexible and nonplastic, flexible and plastic, very flexible and very plastic, and very flexible and nonplastic. Poly(vinyl pyrrolidone) is shown as an example of a quite flexible and nonplastic material, with its flexibility and stiffness dependent upon its molecular weight. The effect of plasticizers on polymer behavior is also discussed.

Journal Article
TL;DR: The 7:2:1 (10% TA,-) liposome was the best formulation, due to its small size, low leakage, high stability, and prolonged and sustained release profile.
Abstract: Tranexamic acid (TA) has been claimed to have whitening effects. The effects of TA contents (5% and 10%) and charges on the stability and release of TA entrapped in hydrogenated soya phosphatidylcholine/cholesterol/charged lipid [dicetyl phosphate (-) or stearylamine (+)] liposomes at molar ratios of 7:2:1(-) and 7:2:1 (+) were investigated. The TA contents were determined spectrophotometrically at 415 nm, following derivatization with 2,4,6-trinitrobenzosulfonic acid. Stability and leakage of TA from liposomes were characterized at 4 degrees, 30 degrees and 45 degrees C for 90 days. The leakage rates of TA in negative liposomes were lower than those in positive liposomes. The TA in all liposome formulations was relatively stable, as > 90% of total drug remained after up to two months. The release of TA from liposomes was examined using vertical Franz diffusion cells at 37 degrees C for 24 h. The release rates of TA from all liposome formulations were approximately 3 times lower than those from solutions. Charges appeared to affect the physical stability, leakage, and shelf life of TA in liposomes, whereas TA concentrations seemed to affect the release of TA. The 7:2:1 (10% TA,-) liposome was the best formulation, due to its small size, low leakage, high stability, and prolonged and sustained release profile.

Journal Article
TL;DR: The protective effects of the P. persica extract were evaluated against solar ultraviolet (UV)-induced skin damage using in vivo animal models of UVB-induced erythema in guinea pigs and ear edema in ICR mice and suggest that it may be useful for protection when topically applied.
Abstract: The flowers of Prunus persica Batsch have been used for skin disorders in East Asia from ancient times. In this investigation, the ethanol extract from this plant material was prepared and several major constituents were isolated. In addition, the protective effects of the extract were evaluated against solar ultraviolet (UV)-induced skin damage using in vivo animal models of UVB-induced erythema in guinea pigs and ear edema in ICR mice. From the extract, four kaempferol glycoside derivatives were successfully isolated and their contents were measured with HPLC. Among the derivatives isolated, the content of multiflorin B was highest (3.3%, w/w). The P. persica extract clearly inhibited UVB-induced erythema formation dose dependently when topically applied (IC(50) = 0.5 mg/cm(2)). It also inhibited UVB-induced ear edema (49% inhibition at 3.0 mg/ear). Moreover, multiflorin B inhibited UVB-induced erythema formation (80% inhibition at 0.3 mg/cm(2)), indicating that this compound is one of the active principles of the extract. All these results suggest that P. persica extract may be useful for protection against UVB-induced skin damage when topically applied.

Journal Article
TL;DR: Vitamins A and E and ceramide III are not likely to contribute to the hydrating effects of the base moisturizing formulation when assessed by capacitance, at the low doses typically used in cosmetic formulations.
Abstract: Moisturizers containing vitamins A and E as well as ceramides are believed to improve the skin condition by increasing the water content of the stratum corneum. The aim of this research was to evaluate, through the capacitance method (a non-invasive method), the moisturizing effect of an O/W emulsion (non-ionic self-emulsifying base) containing vitamin A palmitate, vitamin E acetate, and ceramide III on human skin. The studies were carried out on a group of 40 healthy Caucasian female test subjects between 30 and 45 years of age, using the Corneometer CM 825 PC. Skin measurements were taken from the volunteers at 7 and 30 days after daily use (twice a day) of the tested products. The presence of vitamins A and E or ceramide III did not cause an improvement in the hydration of the stratum corneum, which means that none of those compounds strengthens the hydration effectiveness of the base formulations used, at least at the doses tested. The interpretation of electrical measurement regarding skin moisture should be made with caution; thus the results observed in this study show the importance of using different approaches (or methodologies) to verify the performance of the formulas tested. We conclude that, at the low doses typically used in cosmetic formulations, vitamins A and E and ceramide III are not likely to contribute to the hydrating effects of the base moisturizing formulation when assessed by capacitance.

Journal Article
TL;DR: This work gives here, through binding experiments, the unambiguous demonstration that SLC is able to antagonize the alpha(2)-adrenergic receptor that is known to reduce intracellular AMPc content and, subsequently, to down-regulate lipolysis.
Abstract: Most of the slimming products already developed for cosmetic applications did not result from strategies that integrate whole lipolysis-regulating mechanisms. We thus focused our attention on a more complete integration of these mechanisms and we developed slimming liposomes (SLC) containing two micro-circulation activators, i.e., esculoside and Centella asiatica extracts, one phosphodiesterase inhibitor, i.e., caffeine, and one fatty acid-beta oxidation activator, i.e., L-carnitine. The validity of our approach was assessed through (a) in vitro tests demonstrating that SLC induced a dramatic increase in the cyclic adenosine monophosphate (cAMP) content in human adipocytes, with a subsequent rise in the nonesterified fatty acids (NEFA) content of human adipocyte incubation medium, and (b) in vivo studies showing that SLC could provide an actual potent slimming effect on human volunteers. Moreover, we give here, through binding experiments, the unambiguous demonstration that SLC is able to antagonize the alpha(2)-adrenergic receptor that is known to reduce intracellular AMPc content and, subsequently, to down-regulate lipolysis. This alpha(2)-adrenergic antagonism has never been reported for any component of SLC, and this work is the first demonstration of the alpha(2)-adrenergic antagonism of such a combination of active liposome compounds.

Journal Article
TL;DR: A candidate reference method is validated that enables the identification and quantification of hair dye-forming compounds and includes common criteria such as the repeatability of the analysis and the establishment of figures of merit.
Abstract: A high range and variety of cosmetic formulations that contain oxidative hair dyes and matrix-forming compounds have been industrially developed over recent years and are now available on the international market. Member states of the European Union are responsible for conducting analyses of cosmetic products as deemed necessary by law and European regulation enforcement. Therefore, inspection authorities as well as the cosmetics trade and industry need validated analytical methods for the identification, characterization, and/or quality control of specific active ingredients or formulations with the aim of implementing the European Union Cosmetic Directives (76/768/ECC, 95/17/EC), In this frame, we validated a candidate reference method that enables the identification and quantification of hair dye-forming compounds. This method consists of a separation by RP-HPLC coupled with a DAD after a liquid-liquid extraction procedure for separating matrix components from the dye-forming compounds. The validation of the method includes common criteria such as the repeatability of the analysis and the establishment of figures of merit, as well as statistical evaluations and quality assurance in order to follow the recommendations of the Eurachem guide for analytical measurements.

Journal Article
TL;DR: Among rosin polymers, polymer 2 (glycerol-based) is reported in the present study as it produced creams with a better stability and release profile as compared to other creams.
Abstract: The literature contains many references to the wide range of uses of rosin-based polymers, but little has appeared in the area of rosin-based polymers used as cream bases. Various rosin polymers based on glycerol, sorbitol, and pentaerythritol were prepared and screened for efficacy as cream bases. Among these polymers, polymer 2 (glycerol-based) is reported in the present study as it produced creams with a better stability and release profile as compared to other creams. The creams were formulated employing polymer 2 (P2) and Tween 60 as surfactants. The stability of the prepared creams, as well as the diclofenac diethylammonium release pattern, was investigated using particle size analysis, conductivity, relative dielectric constant, spreadability, and irritation potential measurement, and was compared with that of creams containing Tween 60 (RT) prepared in the laboratory. The release of the drug, diclofenac diethylammonium, was measured after eight hours and compared with a standard cream (RT) and a marketed cream (RM).

Journal Article
TL;DR: Small-angle x-ray diffraction was used to determine the location of the alpha-hydroxyoctanoic acid in the lamellar liquid crystal, and the final result was a suspension of solid acid particles with dissolved oil and surfactant in a surfactants/oil liquid with only minute amounts of solubilized acid.
Abstract: The phase diagram was determined for the alpha-hydroxyoctanoic acid/Laureth 4/white oil/water system using visual observation with an optical microscope. Typical emulsions were evaporated to determine the structural changes. These were compared to those predicted from the phase diagram. Small-angle x-ray diffraction was used to determine the location of the alpha-hydroxyoctanoic acid in the lamellar liquid crystal. The most important result is the fact that irrespective of initial composition, the final result was a suspension of solid acid particles with dissolved oil and surfactant in a surfactant/oil liquid with only minute amounts of solubilized acid.


Journal Article
TL;DR: The results demonstrate that cosmetic benefits from the use of hydroxy acids are caused by modification of the skin surface, the epidermis, and were more effective when compared with the control and their derivatives in a mouse model.
Abstract: Hydroxy acids have been extensively used in cosmetic and dermatologic formulations because of their satisfactory results in terms of maintaining a young and healthy skin and in recovering aged skin. The purpose of the present study was to examine whether treatment with glycolic acid, lactic acid, a fruit acids mixture, malic acid ester, or salicylic esters of lipophilic acid produces different cosmetic results and produces changes in hairless mice epidermis. Histopathologic, morphometric, and stereologic studies were carried out to investigate the possible alterations caused by formulations containing hydroxy acids or derivatives. Statistical analysis from the results indicate that, under present experimental conditions, formulations containing glycolic acid or lactic acid or a fruit acids mixture or malic acid ester acted on the epidermis, causing a thickening of the epithelium where the basal and spinous layers also showed increased thickness. The cells reached the largest volume, and the nuclei were also more voluminous. The results demonstrate that cosmetic benefits from the use of hydroxy acids are caused by modification of the skin surface, the epidermis. The hydroxy acids were more effective when compared with the control and their derivatives in a mouse model.


Journal Article
TL;DR: The optical properties of hair fibers were studied, focusing on the reflections (highlights) from both the front and the back surfaces of the fiber in consideration and on the effect these have on the perceptions of hair appearance.
Abstract: The optical properties of hair fibers were studied, focusing on the reflections (highlights) from both the front and the back surfaces of the fiber in consideration and on the effect these have on the perceptions of hair appearance. The two reflections are distinguished from each other by sight, because only the back surface reflection is colored by melanin granules and/or dyestuffs inside the fiber. When we observe a flat plate as a model for hair without a cuticle structure, the visual angle between the two light loci correlates with the thickness of the model plate and gives an impression of depth. In the case of hair with a cuticle angle, the visual angle is maintained even when the fiber thickness is reduced. This visual angle causes an overestimation of the thickness and enhances the impression of depth. The visual angle changes dramatically with a curl curvature change of the hair tress, meaning that the impression of depth is also dynamically changed by a small change in hairstyle. The dynamic change in the impression of depth probably causes a vibrant impression. The following are required for beautiful hair appearance along with an impression of depth and vibrancy: (a). Internal structure without light scattering origins is essential to observe vivid colored highlights from the back surface. (b). Well-ordered cuticles are essential to get intensive double highlights from the front and back surfaces. (c). A properly curved hairstyle is essential to obtaining a more vibrant impression.

Journal Article
TL;DR: The use of a polysorbate 80 concentration of 5% by weight can be proposed for stable oil-in-water emulsions of isopropyl myristate in glycerol-and-water mixtures.
Abstract: Phase studies were carried out on systems consisting of isopropyl myristate, polysorbate 80, glycerol, and water. The stable oil-in-water emulsion regions were identified. An influence of the glycerol-to-water ratio on the area of existence of stable emulsions was obtained. The Coulter counter technique was used to determine the droplet size in oil-in-water emulsions. A decrease in average particle size with an increase in glycerol and polysorbate concentration was observed 24 hours after the preparation. Rheologically, the emulsions displayed Newtonian behavior. Their viscosities increased with increasing glycerol and polysorbate concentrations. The influence of glycerol and polysorbate concentrations on the cream separation of one-month-old emulsions indicated an increase in emulsion stability with the increase in glycerol and polysorbate concentrations. The use of a polysorbate 80 concentration of 5% by weight can be proposed for stable oil-in-water emulsions of isopropyl myristate in glycerol-and-water mixtures.

Journal Article
TL;DR: A technique to assay for the activity of antioxidants in a finished cosmetic product by adapting the Randox Assay for Total Antioxidant Status kit so that diluted samples could be evaluated by kinetic as well as end-point determinations is developed.
Abstract: The aim of this study was to develop a technique to assay for the activity of antioxidants in a finished cosmetic product. This was accomplished by adapting the Randox Assay for Total Antioxidant Status kit so that diluted samples could be evaluated by kinetic as well as end-point determinations. Using this technique, we found that a finished product had an IC(50) of 0.07 gm of product and a relative antioxidant activity concentration of 52.7 nmoles/mg.

Journal Article
TL;DR: A simple and rapid procedure is described for the isolation, silylation, and simultaneous capillary gas chromatographic quantitation of alpha hydroxy acids and beta Hydroxy acids in various personal care products.
Abstract: A simple and rapid procedure is described for the isolation, silylation, and simultaneous capillary gas chromatographic quantitation of alpha hydroxy acids and beta hydroxy acids in various personal care products. The sample is dissolved in acidified N,N-dimethylformamide to simultaneously acidify/extract the hydroxy acids; a portion is then trimethylsilyl derivatized with BSTFA and quantified by capillary gas chromatography (GC) using flame ionization detection.

Journal Article
TL;DR: The Food and Drug Administration has completed a survey of consumer and salon/professional cosmetic products for glycolic and lactic acids, and product pH, to determine conformity with recommended levels established by the Cosmetic Ingredient Review (CIR).
Abstract: The Food and Drug Administration has completed a survey of consumer and salon/professional cosmetic products for glycolic and lactic acids, and product pH, to determine conformity with recommended levels established by the Cosmetic Ingredient Review (CIR). In twenty-five consumer products, concentrations of glycolic and lactic acid ranged from 1.1% to 8.7%. Two products had pHs lower than the recommended minimum of 3.5. In seventeen salon/professional products, glycolic and lactic acids were found at levels ranging from 0.9% to 28.5%. Two salon products had pHs significantly lower than the 3.0 recommended by the CIR. About half of the products contained either a sunscreen or a recommendation for the use of a sunscreen.

Journal Article
TL;DR: A method has been developed and validated for the analysis of commonly used intermediates of oxidative hair dyes in commercial cosmetic formulations, including both liquid and cream forms, in dark and blonde shades, found to be highly suitable for the identification and quantification of dye intermediates.
Abstract: A method has been developed and validated for the analysis of commonly used intermediates of oxidative hair dyes in commercial cosmetic formulations, including both liquid and cream forms, in dark and blonde shades. The commercial formulations are submitted to extraction by an organic solvent, and the resulting aqueous phase is analyzed by reverse-phase HPLC with a gradient elution and detection with DAD and/or ESI-MS-MS. A spectra library containing 200-400 nm spectra of the target substances and their HPLC retention times has been recorded for the identification. The quantification of the target substances is also performed after spiking of the commercial formulations, using an external calibration. The recoveries obtained are very good for all selected intermediates. The whole procedure has been found to be highly suitable for the identification and quantification of dye intermediates. Also implemented has been a database containing (a) the retention times, (b) the spectral, MS, and MS/MS characteristics of the intermediates, (c) acidity constant values of some intermediates of interest experimentally determined and compared to the available NIST values, (d) the chromatographic conditions used, (e) the behavior towards extraction of dye intermediates, and (f) matrix compounds.

Journal Article
TL;DR: Model mechanical calculations were carried out to simulate the properties of hair fiber assemblies operating in the bending mode, suggesting a good agreement between the theoretical and experimental data.
Abstract: Model mechanical calculations were carried out to simulate the properties of hair fiber assemblies operating in the bending mode. It was assumed that the fibers were in omega-loop configuration (as in experimental work), and the theory of deformation of thin rings provided a fundamental relationship between stress and strain. A dependence on the stiffness of multi-fiber assembly was derived and verified empirically. Theoretical bending stiffness for fixative-treated hair was calculated for various model fiber distributions by calculating their area moment of inertia according to the parallel axis theorem. General equations for stiffness of fiber assemblies were derived for cross sections placed on cubic and hexagonal lattices. The results suggest a good agreement between the theoretical and experimental data.