Sunscreen Active Ingredients Research Articles

Safety Study of Purple Sweet Potatoes Leaves Extract (Ipomoea batatas (l.) Lamk) Antin-3 Variety as a Sunscreen Active Ingredient on Human Skin

Background: Ultraviolet (UV) radiation intensively has known as a major cause of photoaging and photodamage on skin. Anthocyanin is one of flavonoid group, which has a chromophore and conjugated double bond, absorbing electromagnetic radiation in UV wavelength. Ethanolic leaves extract of (Ipomoea batatas (L.) Lamk) Antin-3 variety contains considerably high anthocyanins so that it can be a potential sunscreen active ingredient. However, the safety effect of ethanolic extract of (Ipomoea batatas (L.) Lamk) Antin-3 variety on human skin is still unclear. Objective: The objective of this study is to evaluate the safety (irritation and allergic effect) of ethanolic leaves extract of (Ipomoea batatas (L.) Lamk) Antin-3 variety on human skin trough a patch test. Materials and Methods: Ethanolic young and old leaves extract of (Ipomoea batatas (L.) Lamk) Antin-3 variety. Each of them is on a 500, 1000 and 5000 ppm on vaselinum album base. The patch test was applied on the back skin on seven of adult females who are included in inclusion criteria (as a subject study) for 24 hours and they were observed for four days. Results: There are two out of seven subjectsindicated irritation which understandably were caused by the old leaves 1000 and 5000 ppm. Conclusions: The old leaves vary in the phytochemical compound compared to the young leaves which have more potential risk to irritate and cause allergies to the human skin. Anthocyanin is a major content in young leaves.

Safety Threshold Considerations for Sunscreen Systemic Exposure: A Simulation Study.

Sunscreens are regulated as over-the-counter drugs in the United States. Some sunscreen ingredients are absorbed into the systemic circulation, which raises concerns about the safety of these drugs. There is limited information on the systemic exposure for most sunscreen ingredients. This report estimates the systemic absorption of two sunscreen active ingredients, oxybenzone and enzacamene, by developing a pharmacokinetic model from published sunscreen absorption data and compares the results with safety thresholds proposed by the US Food and Drug Administration and in the literature. Our analysis indicates that systemic absorption can be substantial, and evaluation of the systemic exposure of sunscreen ingredients is warranted to better assess any long-term risks ofuse.

From fundamental science to product: a bottom-up approach to sunscreen development.

Despite the pivotal role of ultraviolet (UV) radiation in sustaining life on Earth, overexposure to this type of radiation can have catastrophic effects, such as skin cancer. Sunscreens, the most common form of artificial protection against such harmful effects, absorb UV radiation before it reaches vulnerable skin cells. Absorption of UV radiation prompts ultrafast molecular events in sunscreen molecules which, ideally, would allow for fast and safe dissipation of the excess energy. However, our knowledge of these mechanisms remains limited. In this article, we will review recent advances in the field of ultrafast photodynamics (light induced molecular processes occurring within femtoseconds, fs, 10-15 s to picoseconds, ps, 10-12 s) of sunscreens. We follow a bottom-up approach to common sunscreen active ingredients, analysing any emerging trends from the current literature on the subject. Moreover, we will identify the main questions that remain unanswered, pinpoint some of the main challenges and finally comment on the outlook of this exciting field of research.

Sunscreen delays prompt push for high-throughput tests

Sunscreen manufacturers are urging the U.S. FDA to relax testing requirements for new active ingredients, claiming the tests are too costly, animal intensive, and slow. Companies want instead to use high-throughput, nonanimal methods. Animal welfare groups and some members of Congress support the idea. In a Jan. 17 letter to the director of the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods, Rep. Robert Pittenger (R-N.C.) asked what the center is doing “to facilitate the regulatory acceptance of alternatives to animal testing for sunscreen ingredients.” The Sunscreen Innovation Act, enacted in 2014, set deadlines for FDA to review new sunscreen active ingredients, but it did not eliminate the need for FDA to determine that each substance is “generally recognized as safe and effective.” Eight ingredients—amiloxate, bemotrizinol, bisoctrizole, drometrizole trisiloxane, ecamsule, enzacamene, iscotrizinol, and octyl triazone—were under review when the la...

Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite.

In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography–mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdown products identification than n-hexane. Reaction of EHMC with HOCl lead to the formation of C=C bridge cleavage products such as 2-ethylhexyl chloroacetate, 1-chloro-4-methoxybenzene, 1,3-dichloro-2-methoxybenzene, and 3-chloro-4-methoxybenzaldehyde. High reactivity of C=C bond attached to benzene ring is also characteristic for MCA, since it can be converted in the presence of HOCl to 2,4-dichlorophenole, 2,6-dichloro-1,4-benzoquinone, 1,3-dichloro-2-methoxybenzene, 1,2,4-trichloro-3-methoxybenzene, 2,4,6-trichlorophenole, and 3,5-dichloro-2-hydroxyacetophenone. Surprisingly, in case of EHMC/HOCl/UV, much less breakdown products were formed compared to non-UV radiation treatment. In order to describe the nature of EHMC and MCA degradation, local reactivity analysis based on the density functional theory (DFT) was performed. Fukui function values showed that electrophilic attack of HOCl to the C=C bridge in EHMC and MCA is highly favorable (even more preferable than phenyl ring chlorination). This suggests that HOCl electrophilic addition is probably the initial step of EHMC degradation.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-015-5444-0) contains supplementary material, which is available to authorized users.

Hazy Outlook For U.S. Sunscreen Users

AS summer approaches, bringing time in the sun, people in the U.S. are no closer to benefiting from advanced sunscreen active ingredients than they were a decade ago. European outdoors lovers, meanwhile, can bask in the sun knowing they have access to new and highly effective sunscreens. These products protect them from ultraviolet (UV) rays that cause sunburn and contribute to wrinkling and increasing rates of skin cancer. U.S. consumers don’t have access to eight advanced European sun-filtering molecules because the Food & Drug Administration is not convinced they are safe for users. Chemical and cosmetics industry executives counter that people are being denied potentially lifesaving protection. Despite legal efforts to break the stalemate, the wrangling could go on for many more years. Most sunscreen actives protect users against UV-B rays with wavelengths between 290 and 320 nm, the primary culprits in sunburn. Some also protect against UV-A rays in ...

Altered UV absorbance and cytotoxicity of chlorinated sunscreen agents

Sunscreens are widely utilized due to the adverse effects of ultraviolet (UV) radiation on human health. The safety of their active ingredients as well as that of any modified versions generated during use is thus of concern. Chlorine is used as a chemical disinfectant in swimming pools. Its reactivity suggests sunscreen components might be chlorinated, altering their absorptive and/or cytotoxic properties. To test this hypothesis, the UV-filters oxybenzone, dioxybenzone, and sulisobenzone were reacted with chlorinating agents and their UV spectra analyzed. In all cases, a decrease in UV absorbance was observed. Given that chlorinated compounds can be cytotoxic, the effect of modified UV-filters on cell viability was examined. Chlorinated oxybenzone and dioxybenzone caused significantly more cell death than unchlorinated controls. In contrast, chlorination of sulisobenzone actually reduced cytotoxicity of the parent compound. Exposing a commercially available sunscreen product to chlorine also resulted in decreased UV absorbance, loss of UV protection, and enhanced cytotoxicity. These observations show chlorination of sunscreen active ingredients can dramatically decrease UV absorption and generate derivatives with altered biological properties.

Characterization of the UVA Protection Provided by Avobenzone, Zinc Oxide, and Titanium Dioxide in Broad-Spectrum Sunscreen Products

Solar UV radiation (UVR) is composed of UVB (290-320 nm) and UVA (320-400 nm) wavelengths. Only two sunscreen active ingredients approved in the US, avobenzone (butylmethoxydibenzoylmethane) and zinc oxide (ZnO), provide true broad-spectrum protection against UVA wavelengths >360 nm. Although effective against shorter UVR wavelengths <360 nm, titanium dioxide (TiO(2)) is also often believed to confer broad-spectrum protection and is substituted for ZnO or avobenzone. To sustain its absorption capacity within a sunscreen film during UVR exposure, avobenzone needs to be formulated into sunscreen products using sound formulation strategies. To characterize the efficacy of avobenzone, ZnO, and TiO(2) in terms of their abilities to provide broad UVA protection and to demonstrate the effectiveness of the different formulation strategies used today to maintain the efficacy of avobenzone even during prolonged exposures to UVR. UVA efficacy was assessed by measuring absorbance profiles in vitro using Vitro Skin® (IMS Inc., Orange, CT, USA) as an inert substrate and by determining UVA protection factors (PFA) on human skin. The impact of avobenzone loss on sun protection factor (SPF) and PFA values was evaluated by serially reducing avobenzone concentrations in an otherwise photostable product. The photostabilizing influence of specific formulation ingredients was monitored by measuring the extent to which they prevented UVR-induced degradation of avobenzone, whereas photostability of commercial sunscreen products was quantified by measuring the percentage change in absorbance within the UVB and UVA spectral regions following irradiation of thin product films on inert substrates. Model formulations containing 3% avobenzone or 5% ZnO provided superior attenuation of UVA wavelengths >360 nm compared with formulas containing 5% TiO(2). Additionally, sunscreen products of similar SPF containing avobenzone or ZnO exhibited significantly higher PFA values than those containing TiO(2). The addition of photostabilized avobenzone or ZnO increased PFA values nearly 3-fold, whereas the addition of TiO(2) increased PFA values only modestly. Judicious selection of sunscreen actives alone or in combination with extra stabilizing agents maintained the photostability of avobenzone in formulations to deliver sustained broad-spectrum absorbance during 4 hours of exposure to UVR. Small losses (<20%) of avobenzone did not significantly reduce a product's protective effects as measured by SPF and PFA values on human skin. TiO(2) provided neither the same level of UVA attenuation nor the same degree of UVA protection on human skin as did products containing photostabilized avobenzone or ZnO. Hence, TiO(2) cannot be considered a substitute for avobenzone or ZnO in providing high levels of UVA protection to human skin. Use of proper formulation strategies can ensure that avobenzone losses are minimized to the extent that they have no impact on a product's ability to deliver sustained protection, even over periods of prolonged exposure to UVR.

1,3-Diferuloyl-sn-glycerol from the biocatalytic transesterification of ethyl 4-hydroxy-3-methoxy cinnamic acid (ethyl ferulate) and soybean oil

1,3-Diferuloyl-sn-glycerol is found ubiquitously throughout the plant kingdom, possessing ultraviolet adsorbing and antioxidant properties. Diferuloyl glycerol was synthesized and isolated as a byproduct in up to 5% yield from a pilot plant scale packed-bed, biocatalytic transesterification of ethyl ferulate with soybean oil or mono- and diacylglycerols from soybean oil. The yield of the diferuloyl glycerol byproduct was directly proportional to the overall water concentration of the bioreactor. The isolated diferuloyl glycerol exhibited good ultraviolet adsorbing properties, 280-360 nm with a lambda(max) 322 nm, and compared well to the efficacy of commercial sunscreen active ingredients. The antioxidant capacity of diferuloyl glycerol (0.25-2.5 mM) was determined by its ability to scavenge 2,2-diphenyl-1-picrylhydrazyl radicals and was comparable to that of ferulic acid. At current pilot plant scale production capacity, 120 kg diferuloyl glycerol byproduct could be isolated per year.

Ultraviolet resonance Raman spectroscopy as a robust spectroscopic tool for in situ sunscreen analysis

Current techniques being used for sunscreen analysis are incapable of direct determination of the active ingredients in sunscreen formulations. Therefore, the development of methodologies for rapid in situ analysis of sunscreens is desirable. This paper describes the application of ultraviolet resonance Raman spectroscopy (UVRRS) to the direct in situ analysis of sunscreen formulations. High-quality UV resonance Raman spectra were obtained for five sunscreen active ingredients (AIs), mixtures of the AIs and real sunscreen formulation samples. The spectra from the sunscreen formulations gave distinct spectral signatures indicative of the sunscreen AIs in each sample, with essentially no interference from the complex sunscreen matrix. Also, despite the fact that many of the AIs are fluorescent, no fluorescence interferences in the resonance Raman spectra were observed. Excitation wavelength-dependent studies throughout the 244–275 nm region demonstrate that the best discrimination of the AIs was achieved at an excitation wavelength of 244 nm. Thus, by tuning the excitation wavelength within the absorption bands of the AIs, complete identification of these analytes can be achieved in situ without any sample pretreatment or separation. The limit of detection found for a common AI in situ with this technique is 0.23% (w/w), the limit of quantitation is 0.78% (w/w), while the dynamic range is between 0.8% and 50% (w/w). The technique is fast, robust, lacks any major interference, and can be adapted for routine online quality control.

Enhancing high SPF, high UVA protection through the use of organic and inorganic sunscreen active ingredients

Enhancing high SPF, high UVA protection through the use of organic and inorganic sunscreen active ingredients

Starch-encapsulated, soy-based, ultraviolet-absorbing composites with feruloylated monoacyl- and diacylglycerol lipids

Ferulic acid is a hydroxy cinnamic acid derivative found ubiquitously throughout the plant kingdom, is especially abundant in rice and corn bran, and possesses excellent ultraviolet (UV) and antioxidant properties. Ferulic acid was enzymatically incorporated into soybean oil to form feruloylated monoacyl- and diacylglycerols (FAG). The FAG possess the UV-absorbing and antioxidant properties of ferulic acid but are water insoluble and extremely lipophilic. These characteristics make FAG attractive in the cosmeceutical industry as an all-natural replacement for petroleum-based sunscreen active ingredients and antioxidants. The FAG were synthesized from the transesterification of soybean oil with ethyl ferulate catalyzed by the commercial lipase, Novozym 435 ( Candida antartica lipase B). The FAG were encapsulated as microdroplets within a starch matrix via steam jet cooking (140 °C and 225 kPa). Up to 50% (w/w) of the feruloylated lipids was encapsulated into the starch matrix with the microdroplets ranging in size from 1 to 10 μm. Transmittance and irradiance measurements of UV radiation (300–400 nm) through thin films of neat FAG (not manipulated after FAG synthesis) and starch-encapsulated FAG showed that the FAG retained its ultraviolet-absorbing efficacy after steam jet cooking. Furthermore, starch-encapsulation of the FAG was found to enhance the ultraviolet absorbance of the feruloylated lipids. When encapsulated at 50% (w/w) in the starch matrix, one-half of the coverage (mg/cm 2) of FAG was required to block the same amount or more UV radiation as neat FAG. The starch-encapsulated FAG was formulated as an aqueous dispersion without the need for emulsifiers or surfactants. The dispersions were drum dried to a powder and shown to be easily reconstituted into water dispersions without the loss of ultraviolet-absorbing efficacy.

NEW-WAVE SUNSCREENS

THE REST OF THE WORLD BENEFITS FROM A VARIETY of sunscreen active ingredients and effectiveness rating systems that aren't available in the U.S. The Food & Drug Administration has promised to give ...

Cinnamoyl esters of lesquerella and castor oil: Novel sunscreen active ingredients

AbstractLesquerella and castor oils were esterified with cinnamic acid (CA) and 4‐methoxycinnamic acid (MCA). Esterification of the hydroxy oils reached 85% completion with CA and 50% conversion with MCA. The hydroxy oils were esterified at 200°C under a nitrogen atmosphere within a sealed system. Unreacted CA and MCA were removed from the reaction mixtures by sublimation at 100°C under vacuum. The resultant methoxycinnamic oils possessed a broader, more blue‐shifted UV absorbance, 250 to 345 nm with a λmax of 305 nm, compared with the cinnamic oils, which absorbed from 260 to 315 nm, λmax of 270 nm. The methoxycinnamic oils provide better UV‐B absorption and thus are better candidates to be used as sunscreen active ingredients. Esterifications of the hydroxy oils with MCA at 200°C resulted in conversion of 40% of the MCA to undesirable by‐products. Esterifications with MCA performed at 175°C in the presence of a tin catalyst resulted in similar percent conversions to product without degradation of MCA. Esterifications of lesquerella oil with MCA at 175°C resulted in higher conversions, 43%, than analogous esterifications with castor oil, 29%. The hydroxyl groups of the lesquerella and castor oils provide their excellent emolliency, lubricity, and noncomedogenicity in skin and personal‐care products. Therefore, reactions that convert only 50% of the available hydroxyl groups of the lesquerella oil to cinnamoyl‐esters are preferred.

Solvent effects on sunscreen active ingredients using Raman spectroscopy

AbstractWe present Raman spectra of five sunscreen active ingredients in 10 solvents. Shifts in the UV absorption maxima and the CO Raman mode wavenumber are observed for some of the sunscreens as a function of solvent. Correlations between the observed wavenumber shifts and solvent properties indicate that hydrogen bonding is a key interaction between sunscreen active ingredients and solvent. Interestingly, the relative Raman intensities are also sensitive to the hydrogen‐bonding and polarizability properties of the solvent, reflecting differential stabilization of the sunscreen's resonance structures. These results suggest an ‘expanded polarizability’ view of the solvent's effect on the solute. The observed wavenumber and relative intensity changes were also utilized to identify the active agents present in commercial sunscreen preparations from their in situ Raman spectra. Copyright © 2003 John Wiley &amp; Sons, Ltd.

Advanced Sunscreens: UV Absorbers Encapsulated in Sol-Gel Glass Microcapsules

Undesirable phototoxic and photoallergic reactions accompanying a justified increased use of sunscreen active ingredients within cosmetic products have encouraged the development of new products safer for human use. The sol-gel microencapsulation technology developed utilizes an interfacial polymerization process, allowing for the achievement of transparent silica glass microcapsules with sizes ranging between 0.3–3 microns and a characteristic core-shell structure. Within the sol-gel microcapsule structure a UV absorber core, constituting roughly 80% of the final product weight, is enclosed within a silica shell. These advanced sunscreen actives are then incorporated into a suitable cosmetic vehicle to achieve high Sun Protection Factors (SPF), while affording an improved safety profile, as the penetration of the UV absorbers is markedly reduced.

PUTTING ON A HEALTHY, MORE YOUTHFUL FACE

AN ANNUAL RITE OF SPRING, THE In-Cosmetics show brought together personal care products ingredients suppliers and their customers to review the latest formulation trends. Plant-derived natural ingredients continued to be a big draw at the show, held this year in London's Excel exhibition hall April 9-11. Also remarkable was the number of new hair-fixative polymers from National Starch & Chemical, Noveon, and ISP; sunscreen active ingredients from BASF, Bayer's Haarmann & Reimer unit, and Germany's Merck; and the small but growing number of suppliers of biotechnology-based materials. The 2,850 visitors—about the same number as attended the In-Cosmetics show in Dusseldorf a year ago—continued to find ingredients suppliers eager to satisfy consumer demand for age-defying compounds. Booths that seemed to draw the biggest crowds generally had some stake in the trend toward plant-derived ingredients. Everyone is looking for 'natural' products, said a supplier of synthetic ingredients whose display drew li...

Photochemical formation of singlet molecular oxygen in illuminated aqueous solutions of several commercially available sunscreen active ingredients.

Evidence is presented for the photochemical formation of singlet molecular oxygen (1O2) in air-saturated aqueous solutions of several sunscreen active ingredients using sunlight-range illumination. This is of significance because (1) 1O2 is known to be cytotoxic, and (2) there have been several reports of toxic effects associated with the use of some sunscreens; most notably, with p-aminobenzoic acid (PABA). Illuminated aqueous solutions of PABA, 2-ethylhexyl p-(dimethylamino)benzate (ODPABA), 2-hydroxy-4-methoxybenzophenone (BZ3), 2,2'-dihydroxy-4-methoxybenzophenone (BZ8), 2-ethylhexyl 2-cyano-3,3-diphenylacrylate (OCR), 2-ethylhexyl p-methoxycinnamate (OMC), and 2-ethylhexyl salicylate (OCS) were evaluated individually for 1O2 formation. Furfuryl alcohol (FFA), a well-known chemical trap for 1O2, was added to each of the aqueous sunscreen solutions. The FFA was consumed when solutions of PABA, ODPABA, OMC, and OCR were illuminated, but no loss of FFA other than by direct photolysis occurred in solutions of BZ3, BZ8, or OCS. There was also no significant loss of FFA in any of these solutions kept in the dark. Further evidence for the formation of 1O2 in illuminated aqueous sunscreen solutions is provided by the results of experiments in which individual solutions containing sunscreen active ingredients and FFA that were diluted with D2O exhibited an increased rate of FFA consumption while the addition of azide ion (N3-) reduced the rate of FFA consumption. Continuous sunlight-range illumination of aqueous PABA solutions produced significantly higher steady-state concentrations of 1O2 than in solutions containing any of the other sunscreen active ingredients evaluated. The substituted benzophenone compounds (BZ3 and BZ8) and the salicylate-based compound (OCS) not only appear to produce no 1O2, but they also appear to produce no other reactive oxidant species that are capable of consuming FFA. This indicates that BZ3, BZ8, and OCS may be peferable, from the standpoint of toxic oxidant formation, for use as sunscreen active ingredients when compared to the other compounds evaluated in this study.

The frequency of reactions to sunscreens: results of a longitudinal population-based study on the regular use of sunscreens in Australia

Six-hundred-and-three people aged 40 or more years, from Maryborough in central Victoria, were enrolled in a randomized longitudinal study, which required daily application of either a SPF 15+, broad-spectrum, water-resistant sunscreen cream or the cream base without the active ingredients. The study duration was 7 months, from September 1991 until April 1992. One-hundred-and-fourteen (18.9%) of these subjects developed an adverse reaction to the cream they were applying. Patch testing, photopatch testing and scratch testing with the ingredients of the creams revealed that only a small proportion (< 10%) of the inflammatory eruptions were allergic in nature. None of the people tested was allergic to the sunscreen active ingredients. History and examination findings, where available, suggested that the majority of adverse responses were consistent with an irritant reaction, both to the sunscreen preparation and the base cream control. A higher than expected proportion of the people who developed an adverse reaction had a personal history consistent with atopy. Other reactions included acneiform eruptions and contact urticaria. A frequency of reactions to sunscreen preparations of over 15% means that further work is necessary to improve both the formulation of such products, and the manner and conditions under which they are used, to ensure satisfactory compliance.