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International audience; Objective Growing consumer mistrust of a number of ingredients used in industry has led to the development of a trend for homemade products. This now affects all types of sectors, but particularly the hygiene sector for shampoo and toothpaste products. The aim of this work is therefore to study recipes found on the internet for these types of products in order to assess risks associated with their use.Materials and methods Eighty-four recipes were collected from the internet and their composition was analysed.Results None of the 84 formulas analysed contained any fluoride salts, well known for their oral health benefits. Eighty percent did not contain a foaming agent either, which is very useful in the cleaning function of toothpastes. Furthermore, the quantities of substances to be used were usually expressed in tablespoons or teaspoons, measures which are imprecise and could, for example, lead someone to use large quantities of an abrasive agent such as calcium carbonate.Conclusions Attention should be drawn to homemade toothpaste recipes that contain no fluoride and whose abrasivity, purity and microbial contamination cannot be verified.

Contact dermatitis linked to cosmetic products is a very common reason for visits to the dermatologist, and in more than half the cases, it is due to an allergic reaction. Fragrances are most often the culprit. The aim of the study was to describe the common fragrance allergens in different categories of cosmetic products available on the European market. We wanted to assess the influence of cosmetic type and distribution channel on the presence of fragrance allergens. There are the allergens whose concentration exceeds 0.001% in leave-on products and 0.01% in rinse-off products. A total of 2044 commercial hygiene, care, and makeup cosmetic products were analyzed to specifically study regulated fragrance allergens. The influence that the product category and its distribution channel (retail stores and specialized stores such as beauty institutes or hairdressers and pharmacy) have on the prevalence of these allergens was evaluated. The Kruskal-Wallis test has been used for statistical data analysis. There is a wide range of fragrance allergens, the most common being limonene (found in about 30% of products tested), linalool (just over a quarter of the products tested), and benzyl alcohol (approximately 16% of the products tested). The average number of allergens found and their nature varies depending on the type of product in question (maximum number for shampoos and oral care with about 70 allergens and minimum number for nail polish and makeup for eyes with fewer than 10 allergens). In the area of hygiene, deodorants and oral hygiene products are particularly noteworthy, the former for their significantly high number of allergens and the latter for their low number. There is also a significant difference between the number of allergens found in eye makeup and foundations. Our results indicate that the number of regulated fragrance allergens is particularly influenced by the type of products.

WOS:000569919500022; This study was focused on the phenolic content and associated cosmetic activities of seven brown marine macroalgae:Alaria esculenta,Ascophyllum nodosum,Bifurcaria bifurcata,Fucus serratus,Halidrys siliquosa,Himanthalia elongata, andLaminaria ochroleuca, selected for their abundance in Brittany and their phlorotannin production. Phlorotannins were extracted by maceration followed by a liquid/liquid purification to obtain fractions enriched in phlorotannins. Seasonal and yearly variations in phenolic contents were investigated thanks to the Folin-Ciocalteu assay to find the best harvesting season for each species.H-1 nuclear magnetic resonance (NMR) was used to validate the presence of phenolic compounds and to compare the species in terms of phenolic signals, as they produce different phlorotannin molecules. Activities required for cosmetic applications (i.e., radical scavenging, antioxidant, photoprotective, and anti-aging activities) were assessed by in vitro tests. Fucales, especiallyA. nodosum,F. serratus,H. elongata, andH. siliquosa, showed higher phenolic contents than Laminariales.Temporal variations were apparent for five seaweeds with the highest phenolic content, notably in autumn. The phenolic content was high regardless of the season and antioxidant and photoprotective activities were similar to those of commercial molecules, allowing year-round algal harvesting. The anti-aging activity ofA. nodosumandF. serratusfractions was higher than the active tea flavonol, epigallocatechin gallate. These results are promising for the use of abundant marine macroalgae as a source of natural active ingredients for cosmetic applications.

There are relatively few authorized ultraviolet filters in Europe and this presents a certain number of problems when we want to formulate a sun protection product which both ensures a high level of protection and respects the recommendations in force in terms of broad-spectrum efficacy, with, in particular, a critical wavelength (λc) greater than or equal to 370 nm. A new ultraviolet filter has just been launched on the market. Known as tris-biphenyl triazine, it is the first filter to be registered on Annexe VI of "Cosmetics Regulation" (EC) No. 1223/2009 of the European Parliament and of the Council, which gives a list of the ultraviolet filters allowed in cosmetic products, since the regulation came into force in July 2013. This filter is both very effective (as it enables 2 SPF units and 1 UVA-PF units to be obtained respectively, by percentage of use) and very photostable (since the SPF and UVA-PF do not vary after 2h of irradiation in a solar simulator). Its broad spectrum associated with its qualities in terms of efficacy and photostability make it a choice ingredient for the formulation of sun protection products.

The immunosuppressive properties of Benzophenone-4, an UV-filter and three ingredients, Allantoin, Bisabolol and Enoxolon used in sunscreen formulation, previously characterized as anti-inflammatory compounds, are studied. The results of this study demonstrate that four tested molecules have effects on DCs and T cells which are the most important cells of the immune system. The impact is also visible on keratinocyte cells which are in the direct contact with skin sunscreens. Each ingredient should be used with caution at reduced doses or even removed from some cosmetic preparations, such as sunscreens.

Given that previous studies have highlighted the anti-inflammatory nature, which is influenced by UV radiation, of a certain number of ultraviolet filters currently used in Europe, it seemed interesting to evaluate the persistence of this type of effect. The persistence of the anti-inflammatory effect of fourteen preparations, each containing one of the ultraviolet filters authorized by Regulation (CE) No. 1223/2009, and of 10 commercially-available sun products was studied using the phorbol-myristate-acetate test on mice, up to 6 and a half hours after application. We can observe that a benzophenone, oxybenzone, a PABA derivative, octyldimethylPABA and a derivative of cinnamic acid, OMC as well as 3 commercially-available products, display a very marked anti-inflammatory effect at the end of our experimentation phase. The type of effect observed could encourage users to prolong the time that they are exposed to the sun, due to there being no warning signs, namely sunburn.

In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting. A method to extract and purify marennine has been developed, but its chemical structure could hitherto not be resolved. For decades, H. ostrearia was the only organism known to produce marennine, and can be found worldwide. Our knowledge about H. ostrearia-like diatom biodiversity has recently been extended with the discovery of several new species of blue diatoms, the recently described H. karadagensis, H. silbo sp. inedit. and H. provincialis sp. inedit. These blue diatoms produce different marennine-like pigments, which belong to the same chemical family and present similar biological activities. Aside from being a potential source of natural blue pigments, H. ostrearia-like diatoms thus present a commercial potential for aquaculture, cosmetics, food and health industries.

00000 ăWOS:000390090300038; International audience; The present study focused on a brown macroalga (Halidrys siliquosa), with a particular emphasis on polyphenols and their associated biological activities. Two fractions were obtained by liquid/liquid purification from a crude hydroethanolic extract: (i) an ethyl acetate fraction and (ii) an aqueous fraction. Total phenolic contents and antioxidant activities of extract and both fractions were assessed by in vitro tests (Folin-Ciocalteu test, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power assay, superoxide anion scavenging assay, and beta-carotene-linoleic acid system). For the most active fraction, i.e., the ethyl acetate fraction, the oxygen radical absorbance capacity (ORAC) value, antibacterial activities, and sunscreen potential (Sun Protection Factor and UV-A-Protection Factor) were tested in vitro. A high correlation found between antioxidant activities and total phenolic content was interpreted as the involvement of polyphenolic compounds in antioxidant mechanisms. Interestingly, the ethyl acetate fraction appeared to be a broad-spectrum UV absorber and showed a strong bactericidal activity against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. In this fraction, four phenolic compounds (trifuhalols and tetrafuhalols and, for the first time, diphlorethols and triphlorethols) were identified using 1D and 2D nuclear magnetic resonance (NMR) and MS analysis. These findings are promising for the use of H. siliquosa, abundant in Brittany, as a valuable source of photoprotectant molecules for sunscreen and cosmetic applications.

When determined in vitro, the SPF of certain commercial sunscreen products can be lower than the SPF indicated on the label. The study of the composition of this type of product enabled us to note that the majority contained substances reputed to have anti-inflammatory properties. This effect is shown by inhibiting the erythema, without protecting the skin, which constitutes a serious public health problem. The anti-inflammatory effects of αbisabolol-, allantoin- and 18-β-glycyrrhetinic acid-based emulsions, as well as commercial sun products containing any one of these molecules, have been tested with phorbol myristate acetate on mice. The effectiveness of these sunscreens products is quantified using two indicators: SPF (sun protection factor) and PF-UVA (protection factor-UVA) by in vitro method. We were thus able to show that certain sun products have an anti-inflammatory effect, which in turn causes the SPF value shown on the product to be overestimated, indeed sometimes by considerably large margins.

The aim of this study was to synthesize and characterize Ca-doped CeO 2 nanopowder in order to determine in vitro the photoprotection efficiency of the combination – commercial TiO 2 /Ca-doped CeO 2 – incorporated in emulsion. Cerium based particles were synthesized by two methods, co-precipitation and spray pyrolysis, in order to study the effect of the synthesis method on the photoprotection results. While both samples synthesized by co-precipitation and spray pyrolysis methods present the same crystalline structure and the same elementary composition, they differ in granulometry. The photoprotection results showed that the combinations tested are more efficient than the classical combination TiO 2 /ZnO in both UVB and UVA ranges. While the combination TiO 2 /CeO 2 synthesized by co-precipitation allows an increase of the SPF of 27% compared to the classical combination, the combination TiO 2 /CeO 2 synthesized by spray pyrolysis allows an increase of the PF-UVA of 19%.

Hematite nanoparticles were synthesized for ultraviolet filtration application by the precipitation method followed by calcination at different temperatures. A range of crystallite sizes between 37 and 85 nm (as determined by the Scherrer formula) was obtained, according to the temperature used for the calcination. An increase in the absorbance with increasing crystallite size was observed over the whole ultraviolet B and A range. The experimental band gap was 2.94 eV for the sample calcined at 500 degrees C and 3.08 eV for the sample calcined at 300 degrees C. The in vitro sun protection factor and protection factor-ultraviolet A of a water-in-oil emulsion made with the sample calcined at 500 degrees C as active ingredient were 9.21 and 8.81, respectively, which is higher than the protection factor-ultraviolet A values obtained for titanium dioxide and zinc oxide at the same mass concentration. The emulsion was found to be photostable.

The objective of this research was to evaluate the efficacy of various sunscreen agents incorporated into an O/W emulsion. Within the scope of this study only an in vitro method was used. According to selected filter UVA, we can obtain more or less effective creams. With the seven available filters, we can cover a range of values between 2 and 12. In addition to these seven filters absorbing in UVA range, variously coated titanium dioxide and zinc oxide were tested as well. So it appears that the best organic UVA filter is anisotriazine at 10% (PF-UVA = 11.82). Its effectiveness is comparable with that of the titanium dioxide forms used at 25%. Photostability in Suntest showed that the more photostable UVA-filters are the benzophenones.

This paper describes the effect on Sun Protection Factor (SPF) of the combination of inorganic and organic filters in sunscreen products as determined by an in vitro method. O/W emulsions containing inorganic filters, such as titanium dioxide and zinc oxide, combined with 18 EU-authorized UV-B organic filters were tested. SPF measurements were carried out using a spectrophotometer equipped with an integrating sphere. This study observed a synergic effect when titanium dioxide was combined with either anisotriazine or octyldimethylPABA. The combination of zinc oxide with 11 UV-B organic filters also exhibited a similar synergy; however, the measured SPF was systematically lower than the protection factor achieved with titanium dioxide.

In temperate saltmarshes, halophytic plants have to daily protect their internal tissues against sunlight and UV rays. Consequently, they develop adaptive responses such as the synthesis of secondary metabolites, including polyphenols. The present study focused on the biological activities of fractions enriched in polyphenols from Salicornia ramosissima. Three different extracts were obtained by purification processes to concentrate polyphenols: a crude hydroalcoholic extract, and two purified fractions: an ethyl acetate fraction (EAF) and an aqueous fraction. Phenolic and flavonoid contents, antioxidant (DPPH radical-scavenging activity, reducing activity, beta-carotene linoleic acid system and the ORAC method) and sunscreen properties (Sun Protection Factor and UVA-Protection Factor) were assessed by in vitro tests. The purification process was effective in increasing phenolic and flavonoid contents as well as antioxidant and sunscreen capacities of the EAF. The EAF appeared to be a broad spectrum UV absorber. The chemical structure of 10 EAF polyphenols was elucidated using 2D NMR and mass spectrometry spectra. Furthermore, a correlation was observed between phenolic composition and biological activity. These findings are encouraging for the future use of S. ramosissima as a potential source of antioxidant and photoprotectant molecules for industrial applications.

With the aim to know the remanence of two sunscreens, PEG-25 PABA and benzophenone, two cases have been considered: the application of aqueous solution of two filters studied for the application of oil-in-water (O/W) emulsions containing the same two filters on the skin of 21 voluntary women. In order to determine the quantity of filter remaining in the stratum corneum after times of application, which vary from 1 to 7 h, a series of six strippings have been carried out. The sunscreen agents were assessed by HPLC. With this study, it has been possible to emphasize the best remanence of benzophenone 4. Moreover, the incorporation of photo-protective agents in a O/W emulsion promotes their penetration, and this is particularly due to benzophenone 4.

L'objectif de ce travail est l'etude de la photodegradation de solutions aqueuses d'aspartame 3,4 × 10 -3 M (λ max = 257 nm, e = 180 M -1 .cm -1 ). Le dosage de l'aspartame a ete effectue en chromatographie liquide haute performance. On a ainsi pu mettre en evidence que la photodegradation de cet edulcorant suivait une cinetique d'ordre un. La constante de vitesse de reaction de degradation a pH 5 est de 3,47 x 10 -3 min -1 .

The objective of this research was to study the effect of pH on the photodegradation kinetics of 15.8 μg.ml-1 aqueous solutions of climbazole. A high-performance liquid chromatographic method for the quantification of climbazole after irradiation of aqueous solutions was carried out, using a RP-18 column with a acetonitrile - 0.05 M sodium perchlorate mobile phase. The detector was set at a wavelength of 220 nm. Calibration curve showed linear response in the interval 5 to 25 μg.ml-1. Photodegradation appeared to follow first-order kinetics and was found pH-dependent. The degradation rate constant was calcu- lated to be 10.5 〈 10-3, 9.9 〈 10-3 and 16.5 〈 10-3 min-1, respectively at pH 5, 7 and 9.

The objective of this research is to evaluate the thermal stability of monoammonium glycyrrhizinate. Thermodegradation of solutions of monoammonium glycyrrhizinate at various temperatures (50, 70 and 90 degrees C) was studied. This degradation appeared to follow first-order kinetics independently of temperature and was found to be pH dependent. The experiments revealed an activation energy (Ea) of about 33 kJ mol-1 and a t 90% of about 3 years at 20 degrees C in a pH range from 7 to 9. So it can be concluded that monoammonium glycyrrhizinate is stable in a pH range from 7 to 9. It can be interesting for use in oral care or in food industry.

The objective of this research is to evaluate the stability of climbazol. Thermodegradation of solutions of climbazol at various temperatures (50, 70 and 90°C) was studied. This degradation appeared to follow first-order kinetics whatever the temperature. The experiments revealed an activation energy Ea of 5.4 kcal mol−1 and a time necessary to obtain a decrease of 10% of the initial concentration, t90%, of 81.9 days for climbazol in aqueous diluted solution at 20°C.

The target of this research was to determine the cytotoxicity of sodium laurylsulfate on single-layer cultures of human fibroblasts, using two colorimetric methods (neutral red and MTT tests) and the evaluation of the pyruvic acid consumption by the cells. For the determination of the cytotoxicity by colorimetric tests, we have determined the absorbance at 540 nm using a spectrophotometer. Pyruvic acid, present in the culture medium, is the mitochondria’s C 3 energetic metabolite. So, a measure of the cell’s consumption of pyruvic acid was developed. The reaction is as follows: Pyruvic acid + NADH → Lactic acid + NAD + and the enzyme employed is the LDH (lactate dehydrogenase). This method can be used to measure cytotoxicity, proliferation, and the cell’s activation. The method is rapid, precise, and lacks any toxic byproduct. The absorbance was measured using a spectrophotometer at 340 nm. The consumption of pyruvic acid follows upon the fibroblast’s growth. Sodium laurylsulfate cytotoxicity test after 24 h shows that the NR colorimetric test and the pyruvic acid consumption are correctly correlated ( r = 0.91, α = 0.05). This dosage can be used to study the barrier properties of the corneocyte layer without destroying the artificial skin.

The objecti ve of this work was the evaluation of neohesperidin dihydrochalcone thermostability. For this acceler ated stability stud y, we ha ve used an isothermal method at three temper atures (50, 70 and 90 °C). The thermodegradation of aqueous diluted solutions of neohesperidin dihydrochalcone at various pH was studied . This degradation appeared to follow first-order kinetics and was found to be pH-dependent. In the best stability conditions (pH = 4.50), the experiments revealed an acti vation energy ( Ea) of 45.8 kJ mol -1 and a t90% of 164 days, at 20 °C.

A certain number of filters have notable anti-inflammatory properties with percentage inhibition of PMA-induced edema in mice at over 70%. The question arose as to whether this effect was likely to continue after UV irradiation. It can be noted that 7 filters retain an equivalent anti-inflammatory effect before and after 2h of irradiation in a Suntest device (650 W/m(2)). For 9 filters, the anti-inflammatory effect decreases and for 5 filters, the anti-inflammatory effect increases. Various behaviors should be noted. 3 groups of substances can be distinguished: such as phenylbenzimidazole sulfonic acid which loses its anti-inflammatory character after irradiation (the percentage inhibition falls from 80 to 44%), oxybenzone which retains a constant anti-inflammatory character (89% inhibition before and after irradiation and also octyl methoxycinnamate which becomes very anti-inflammatory (with a percentage inhibition of 93%). The same phenomenon is observed in the case of commercial products. This should be made known as it can have a considerable impact on the results which are displayed on the packaging of sun products.

Depigmentation and skin lightening products, which have been in use for ages in Asian countries where skin whiteness is a major esthetic criterion, are now also highly valued by Western populations, who expose themselves excessively to the sun and develop skin spots as a consequence. After discussing the various possible mechanisms of depigmentation, the different molecules that can be used as well as the status of the products containing them will now be presented. Hydroquinone and derivatives thereof, retinoids, alpha- and beta-hydroxy acids, ascorbic acid, divalent ion chelators, kojic acid, azelaic acid, as well as diverse herbal extracts are described in terms of their efficacy and safety. Since a genuine effect (without toxic effects) is difficult to obtain, prevention by using sunscreen products is always preferable.

Summary The geographical and seasonal variation of 19 free amino acids was investigated in Crithmum maritimum L. (Apiaceae). To meet this goal, isolation, identification and quantitative determination of free amino acids of the halophyte and chasmophyte apiaceous plant were carried all the year 1993 round. Harvested samples were transported at 0°C to the laboratory and washed with water. The technique of HPLC was utilized for qualitative and quantitative determination of the free amino acid pool after extraction. The total nitrogen content is about 2 % dry weight but exist difference according to geographical origin and season. 19 amino acids were recorded in leafy stalks of Crithmum maritimum L. They are the following: aspartic acid, asparagine, glutamic acid, glutamine, alanine, glycine, valine, serine, histidine, threonine, arginine, tyrosine, methionine, tryptophane, phenylalanine, isoleucine, leucine, ornithine and lysine. Histidine is the main free amino acid.

Some UV-filters have side effects. For example, oestrogenic effect was demonstrated for 4-methylbenzylidene camphor. Given that secondary metabolites are known for their UVB photoprotective properties in plants that contain them, we chose to study silymarin as an agent which could potentially be used in sun products. This determination is based on the physical determination of the reduction of the energy in the UV range, through a film of product which has previously been spread on an adequate substrate. About 15 mg of O/W emulsion containing silymarin at various concentrations was applied on roughened PMMA plates and the transmission measurements were carried out using a spectrophotometer equipped with integrating sphere. Incorporated in O/W creams, at a concentration of 10% (w/w), silymarin gives a Sun Protection Factor similar to that of octylmethoxicinnamate, which is why it is predominantly used in Europe. Overall, these results demonstrate that silymarin is a promising new sunscreen agent.

The numerous uses and properties of flavonoids are well known, in particular their antioxidant, cancer-control and anti-inflammatory effects. These properties can be used to enrich the field of topically-applied sun protection. The aim of the study was to determine the effectiveness of various flavonoids and polyphenols. We have used an in vitro method based on the transmittance measurement after spreading an oil in water emulsion containing either flavonoids or polyphenols on polymethylmetacrylate plates. Chlorogenic acid and apigenin were the best UV-filter and UVA-filter, respectively. The flavonoids and polyphenols studied are good candidates for us e in photoprotective products.

We used the neutral red test, MTT assay and lactate dehydrogenase (LDH) release to compare the potential cytotoxicity of six surfactants belonging to different classes--three non-ionic surfactants (Triton x100, octylphenoxypolyethoxy alcohol, from Orion; Tween 60, polyoxyethylene (20) sorbitan monostearate, from ICI Speciality Chemicals; Tween 80, polyoxyethylene (20) sorbitan monolaurate, from Labosi), two anionic surfactants (Texapon K1298, sodium lauryl sulphate, from Henkel; Texapon N40, sodium laurylether sulphate, from Henkel) and one cationic surfactant (benzethonium chloride, from Siber Hegner)--on human fibroblast cultures. According to the LC50 (microg ml(-1)), the tested surfactants can be classified in the following order of increasing cytotoxicity: Tween 80 < Texapon N40 < Tween 60 < Texapon K1298 < Triton x100 < benzethonium chloride.

Topical sunscreens have been used for many years on exposed areas to protect the skin from the damaging effects of ultraviolets. If the sunscreens were essential, it is suggested that they have adverse effects. We chose to study ferulic acid ethyl ester (FAEE) as agent which could potentially be used in sunscreen products. FAEE was incorporated at various concentrations into O/W emulsions. Total of 30 mg of product exactly weighed were spread on poly(methylmethacrylate) plates over the whole surface (25 cm(2)). So, sun protection factor (SPF) and PF-UVA of the creams were measured in vitro. Transmission measurements between 290 and 400 nm were carried out using a spectrophotometer equipped with an integrating sphere. Incorporated in O/W creams, at a concentration of 10%, FAEE give a SPF similar to that of benzymidazilate, a filter permitted in EU.

Water is the most important molecule contained in the skin and is bound to the intracellular hygroscopic substances called natural moisturizing factors (NMF). The clinical characteristic of xerosis is rough and/or coarse skin. This anaesthetic alteration necessitates cosmetic products application. In this study, we tested the efficiency of urea incorporated into six different emulsions (O/W) and 10 different gels. Skin of 10 healthy women (20 to 45 years) was treated using 50 mg of emulsion or gel containing 5% of urea. A skin surface of 16 cm(2) was chosen in the area of the forearm. The gain in moisturizing was performed measuring the skin electrical capacity using a corneometer (Courage & Khazaka, model CM 825), one hour after treatment. Sodium carboxymethyl cellulose gel has the least moisturizing effect. On the other hand, the mixture of polyacrylamide and C13-14 isoparaffin polysorbate 85 can be a good vehicle in the treatment of skin dehydration. Adding various oils (6%) or collagen in aqueous solution does not improve the efficiency of the tested products. Moisturizing effect of gels (polyacrylamine with C13-14 isoparaffin polysorbate 85) is higher than the one of emulsions (L/H).

The target of this research was to evaluate the photostability at various pH values of 1.20 x 10(-4) M aqueous solution of arbutin (lambda max = 267 nm; epsilon = 7500 M-1.cm-1). This photodegradation appeared to follow first-order kinetics whatever the pH. The degradation rate constant was calculated to be 5.5 x 10(-4), 7.0 x 10(-4) and 24.1 x 10(-4) min-1, respectively at pH 5, 7 and 9.

Sunscreen agents are commonly used in cosmetic products to filter out noxious radiation in sunlight. A convenient high-performance liquid chromatographic (HPLC) method for the quantification of five sunscreens after irradiation has been selected. We used this analytical method to compare the photostability of benzophenone-3, PEG-25 PABA, octyl dimethyl PABA, 4-methylbenzylidene camphor and butyl methoxydibenzoylmethane, at levels in the range of 25-60 microM. The assay was carried out, using a C8 column with a methanol--water mobile phase. The detector was set at a wavelength of 300 nm. The assay was linear with the following limits: 0.2 microgram ml-1 for benzophenone-3, 1 microgram ml-1 for PEG-25 PABA, 0.15 microgram ml-1 for octyl dimethyl PABA, 0.1 microgram ml-1 for methylbenzylidene camphor and 0.05 microgram ml-1 for butyl methoxydibenzoylmethane. The half-lives calculated indicate a very good photostability of the sunscreens studied and permit to classify amongst themselves.

Given that flavonoids are known for their ultraviolet (UV)B photoprotective properties in plants that contain them, we chose to study quercetin (1) and rutin (2) as agents that could potentially be used in sunscreen products. These two substances proved to behave in similar ways. When incorporated in oil-in-water emulsions, at a concentration of 10% (w/w), 1 and 2 give sun protection factor (SPF) values similar to that of homosalate, a standard substance. These two flavonoids also provided a non-negligible level of photoprotection in the UVA range. When used in association with titanium dioxide, the SPF obtained was around 30.