Isopropylparaben Research Articles

Exposure and potential risks of thirteen endocrine- disrupting chemicals in pharmaceuticals and personal care products for breastfed infants in China

Ingestion of breast milk represents the primary exposure pathway for endocrine-disrupting chemicals (EDCs) in newborns. To elucidate the associated risks, it is essential to quantify EDC levels in both breast milk and infant urine. This study measured the concentrations of 13 EDCs, including parabens (methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP), iso-propyl paraben, butyl paraben, and iso-butyl paraben), bisphenols (bisphenol A (BPA), bisphenol F, bisphenol S, bisphenol AF, and bisphenol Z), triclosan (TCS), and triclocarban, in breast milk and infant urine to assess their potential health effects and endocrine disruption risks. In total, 1 014 breast milk samples were collected from 20 cities across China, along with 144 breast milk samples and 134 urine samples from a mother-infant cohort in Hangzhou. The EDCs were detected using ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry. Endocrine-disrupting potency was evaluated using a predictive method based on EDC affinity for 15 hormone receptor proteins. The toxicological priority index (ToxPi), incorporating population exposure data, was employed to assess health risks associated with exposure to multiple EDCs. Among the 13 EDCs, MP, EP, PP, BPA, and TCS were detected in over 50 % of breast milk samples, with the highest median concentrations observed for MP (0.37 ng/mL), EP (0.29 ng/mL), and BPA (0.17 ng/mL). Across the 20 cities, 0 %–40 % of infants had a hazard index (HI) exceeding 1. Based on affinity prediction analysis and estimated exposure, cumulative endocrine disruption risk intensity was ranked as MP > TCS > BPA > EP > PP. This research highlights the extensive exposure of Chinese infants to EDCs, offering a detailed analysis of their varying endocrine disruption potencies and underscoring the significant health risks associated with EDCs in breast milk.

Comparative study on estrogen receptor alpha dimerization and transcriptional activity of parabens.

Parabens are used as preservatives in various household products, including oral products, cosmetics, and hair/body washes. In recent years, the widespread use of parabens has raised concerns due to the potential health risks associated with their estrogenic effects. In the present study, we evaluated and compared the estrogenic activity of parabens using two cell-based in vitro tests: (1) bioluminescence resonance energy transfer (BRET)-based estrogen receptor alpha (ERα) dimerization using HEK293 cells that were stably transfected with ERα-fused NanoLuc luciferase (Nluc) and HaloTag (HT) expression vector, and (2) stably transfected transcriptional activation (STTA) assays using ERα-HeLa9903 cells. The following parabens were tested using the BRET-based ERα dimerization assay and showed estrogenic activity (PC20 values): methyl paraben (MP, 5.98 × 10-5M), ethyl paraben (EP, 3.29 × 10-5M), propylparaben (PP, 3.09 × 10-5M), butyl paraben (BP, 2.58 × 10-5M), isopropyl paraben (IsoPP, 1.37 × 10-5M), and isobutyl paraben (IsoBP, 1.43 × 10-5M). Except MP, all other parabens tested using the STTA assay also showed estrogenic activity: EP, 7.57 × 10-6M; PP, 1.18 × 10-6M; BP, 3.02 × 10-7M; IsoPP, 3.58 × 10-7M; and IsoBP, 1.80 × 10-7M. Overall, EP, PP, BP, IsoPP, and IsoBP tested positive for estrogenic activity using both assays. These findings demonstrate that most parabens, albeit not all, induce ERα dimerization and possess estrogenic activity.

THE CHEMICAL COMPOSITION OF PARABEN AND ITS EFFECTS ON HEALTH

Parabens are a group of alkyl esters of p-hydroxybenzoic acid and usually include methyl paraben, ethyl paraben, propyl paraben, butyl paraben, isobutyl paraben, isopropyl paraben and benzyl paraben. Parabens (or their salts) are widely used as preservatives in cosmetics and medicine due to their relatively low toxicity and long history of safe use. Testing of parabens has shown, to varying degrees, that individual paraben compounds have weak estrogenic activity in some in vitro screening tests, such as estrogen receptor ligand binding, regulation of CAT gene expression, and proliferation of MCF-7 cells. Reported in vivo effects include uterine weight gain (eg, butyl, isobutyl, and benzyl parabens) and male reproductive tract effects (eg, butyl and propyl parabens). However, in relation to estrogen as a control during in vivo studies, parabens are much less active than estrogen. While exposure to sufficient doses of exogenous estrogens can increase the risk of certain adverse effects, it is hypothesized that similar risks may arise from exposure to much weaker endocrine-active chemicals (EACs) is still speculation. In evaluating the possibility that exposure to weakly active EACs may be associated with adverse effects due to their endocrine mode of action, it is important to consider both the dose and potency of these compounds compared to estrogen. In this review, a comparative approach involving dose and potency is used to assess whether in utero or adult exposure to parabens may be associated with adverse effects due to their estrogen-modulating mode of action. Keywords: parabens, p-Hydroxybenzoates, PHBA, paraben applications, Methyl paraben.

An environment-friendly approach using deep eutectic solvent combined with liquid-liquid microextraction based on solidification of floating organic droplets for simultaneous determination of preservatives in beverages.

With the increase in environmental protection awareness, the development of strategies to reduce the use of organic solvent used during the extraction process has attracted wide attention. A simple and green ultrasound-assisted deep eutectic solvent extraction combined with liquid-liquid microextraction based on solidification of floating organic droplets method was developed and validated for the simultaneous determination of five preservatives (methyl paraben, ethyl paraben, propyl paraben, isopropyl paraben, isobutyl paraben) in beverages. Extraction conditions including the volume of DES, value of pH, and concentration of salt were statistically optimized through response surface methodology using a Box-Behnken design. Complex Green Analytical Procedure Index (ComplexGAPI) was successfully used to estimate the greenness of the developed method and compare with the previous methods. As a result, the established method was linear, precise, and accurate over the range of 0.5-20 μg mL-1. Limits of detection and limits of quantification were in the range of 0.15-0.20 μg mL-1 and 0.40-0.45 μg mL-1, respectively. The recoveries of all five preservatives ranged from 85.96% to 110.25%, with relative standard deviation less than 6.88% (intra-day) and 4.93% (inter-day). The greenness of the present method is significantly better compared with the previous reported methods. Additionally, the proposed method was successfully applied to analysis of preservatives in beverages and is a potentially promising technique for drink matrices.

A rapid and environmentally friendly method for determination of parabens preservatives in flavors by supercritical fluid chromatography-tandem mass spectrometry.

A rapid method for determination of parabens preservatives (methyl paraben, ethyl paraben, isopropyl paraben, propyl paraben, isobutyl paraben, and butyl paraben) in flavors was established by using supercritical fluid chromatography-tandem mass spectrometry combined with dispersive solid-phase extraction. After adding methanol and primary secondary amine to the sample simultaneously, high extraction efficiency and good sample cleanup could be obtained by simple shaking. Parabens were well separated on a Chiralpak IG-3 column in 6min by gradient elution. Recoveries from spiked blank samples at 0.5, 1.0, and 5.0mg/kg were determined to be 88.3-106.6%with relative standard deviations less than 8.0%. All analytes achieved good linear relation (r ≥ 0.999 2). The limits of detection for all analytes ranged from 0.03 to 0.09mg/kg and the limits of quantification from 0.11 to 0.31mg/kg, respectively. A total of 20 actual samples were successfully analyzed by taking the proposed method. Being simple, rapid, green, and reliable, this method can be taken for the determination of parabens preservatives in flavors.

Parabens in urine of children and adolescents in Germany – human biomonitoring results of the german environmental survey 2014–2017 (GerES V)

Parabens are antimicrobial preservatives used in a wide range of consumer products such as personal care products, cosmetics, pharmaceuticals, and food. Consequently, the general population is ubiquitously exposed to these substances via dermal absorption, ingestion, and inhalation. Parabens promote estrogenic activity and are hence under assessment as endocrine disrupting substances. Urine samples from 3- to 17-year-old children and adolescents (N = 516) living in Germany were analysed for concentrations of nine parabens in the population representative German Environmental Survey for Children and Adolescents 2014–2017 (GerES V). Detection rates and urinary concentrations of the parabens decreased with increasing length of the alkyl chain. Methyl paraben was quantified in 97% of the samples with a geometric mean (GM) concentration of 7.724 μg/L (6.714 μg/gcreatinine), ethyl paraben was quantified in 69% (GM: 0.943 μg/L and 0.825 μg/gcrea), and n-propyl paraben in 31% (GM: 0.563 μg/L and 0.493 μg/gcrea). Concentrations of iso-propyl paraben, butyl paraben, iso-butyl paraben, and benzyl paraben were below the limit of quantification in most samples. Pentyl paraben and heptyl paraben were not detected in any of the samples. Paraben concentrations in urine were found to be associated with frequent usage of leave-on personal care products and cosmetics. Cumulative exposure to parabens (back-calculated daily intakes, expressed as hazard index) was found to be on a level raising concern in up to 14% of the population, mainly driven by n-propyl paraben, and depending on the level of conservativeness and point-of departures used for calculation.

Fabric phase sorptive extraction combined with high-performance-liquid chromatography-photodiode array analysis for the determination of seven parabens in human breast tissues: Application to cancerous and non-cancerous samples

An improved pretreatment approach of human breast tissue is demonstrated for subsequent analysis of seven parabens including methyl paraben (MPB), ethyl paraben (EPB), propyl paraben (PPB), butyl paraben (BPB), isopropyl paraben (iPPB), isobutyl paraben (iBPB), and benzyl paraben (BzPB). Specifically, a well-designed homogenization procedure, conjugated with an optimized fabric phase sorptive extraction (FPSE) protocol, resulted in a carefully outlined sample preparation process as part of a green, simple, sensitive, economical and fast HPLC-PDA analytical method in agreement with Green Analytical Chemistry (GAC) demands. Among all tested FPSE membranes, the highest extraction efficiency was achieved by employing sol-gel poly(tetrahydrofuran) (sol-gel PTHF) coating on 100% cotton cellulose fabric that represents a medium polarity microextraction device, which combined the advanced material characteristics of sol-gel sorbent and the rich surface chemistry of an inherent porous cellulose fabric substrate. The chromatographic separation was accomplished with a Spherisorb C18 column and an isocratic mobile phase consisted of ammonium acetate and acetonitrile at a flow rate of 1.4 mL/min. The total analysis time was 13.6 min. The analytical adequacy of the composite sample preparation and chromatographic separation method was strongly evidenced by its successful application in the bioanalysis of real cancerous and non-cancerous tissue samples originated from different sub regions of human breast including axila, the upper left and the right quadrant. In all samples, at least one paraben was detected, while 35% of the samples were tested positive for all seven target parabens. Moreover, concentration levels of parabens in cancerous tissues were unambiguously higher than in healthy tissues. The obtained results underlined bioaccumulation potential of parabens in human breast tissue as a consequence of constant low-dose exposure of humans, despite the statutory concentration limits. The developed methodology has demonstrated to be suitable and efficient for future epidemiological and toxicological studies.

An improved fabric-phase sorptive extraction protocol for the determination of seven parabens in human urine by HPLC-DAD.

An improved fabric-phase sorptive extraction (FPSE) protocol has been developed and validated herein for the simple, fast, sensitive and green determination of seven parabens-methyl paraben, ethyl paraben, propyl paraben, butyl paraben, isopropyl paraben, isobutyl paraben and benzyl paraben-in human urine samples by HPLC-DAD. The mobile phase consisted of ammonium acetate (0.05 m) and acetonitrile, while total analysis time was 13.2 min. Sol-gel poly (tetrahydrofuran) coated FPSE membrane resulted in optimum extraction sensitivity for the seven parabens. The novel FPSE medium as well as the improved and faster sample preparation procedure resulted in lower limit of detection and quantitation values in comparison with previously reported methods. The separation was carried out using an RP-HPLC method with a Spherisorb C18 column and a flow rate of 1.4 ml/min. The validation of the analytical method was carried out by means of linearity, precision, accuracy, selectivity, sensitivity and robustness. For all seven parabens, the limits of detection and quantitation were 0.003 and 0.01 μg/ml, respectively. Relative recovery rates were between 86.3 and 104%, while RSD values were <12.6 and 19.3% for within- and between-day repeatability, respectively. The method was subsequently applied to real human urine samples.

QuEChERS and C18 as solid phase extraction sorbent - ultra-high performance liquid chromatography -ultraviolet-visible method for determination of parabens in cosmetics products

Concerns are growing about human exposure to endocrine-disrupting chemicals (EDCs), especially during the preadolescent development stage. Parabens are prevalent EDCs widely used as additives in cosmetics. So, the determination of parabens in such products is important. In this study, we developed a reliable and sensitive method to determine simultaneously nine common parabens (methylparaben, ethylparaben, phenylparaben, benzylparaben, penthylparaben, and two groups of isomeric compounds include propylparaben, isopropyl paraben, and butylparaben, isobutylparaben) in cosmetics products. The QuEChERS and solid-phase extraction techniques are used for extraction parabens from non-surfactant cosmetics (perfume, mouth wash solution) and surfactant cosmetics (shampoo, cream, gel), respectively and quantified by using ultra-performance liquid chromatography coupled with the ultraviolet-visible detector. All nine compounds showed good linearity with regression coefficients predominantly above 0.990. The LOD and LOQ of parabens were 0.07 µg/mL; 0.2 µg/mL, respectively. The recoveries ranged from 80 to 110% with the relative standard deviations below 8%. The developed method was successfully applied to determine parabens in various commercial cosmetic products from a local supermarket and the total parabens concentrations are in a wide-ranged from 2.0 to 1270 mg/kg.

A Novel HPLC Method for Simultaneous Determination of Methyl, Ethyl, n-propyl, Isopropyl, n-butyl, Isobutyl and Benzyl Paraben in Pharmaceuticals and Cosmetics.

The alkyl esters of p-hydroxybenzoic acid at the C-4 position, "the parabens," including methyl, ethyl, propyl, and butyl, are widely used as antimicrobial preservatives in foods, cosmetics, and pharmaceuticals. Official regulations on the use of these compounds make their analysis essential for the estimation of their exposure. On this basis, the presented study was realized to develop a simple, selective and cheap high-performance liquid chromatographic method for the quantitative determination of methylparaben, ethylparaben (EP), n-propyl paraben (NPP), isopropyl paraben (IPP), n-butyl paraben (NBP), isobutyl paraben (IBP) and benzyl paraben (BP) in pharmaceuticals and cosmetic products. The chromatographic separation of the analytes was achieved under flow rate gradient elution conditions using a C18-bonded core-shell silica particle column (2.6 μm particle size, 150 × 3.0 mm from Phenomenex Co.). The samples were injected into the system as aliquots of 1.0 μL, and the compounds were detected by using a photodiode array detector set at 254 nm wavelength. With this technique, seven paraben derivatives can be determined in the concentration range of 250-2000 ng/mL. The recovery of the method is in the range of 99.95-13.84%, and the RSD is at a maximum value of 3.95%. The proposed method was fully validated and successfully applied to different pharmaceutical and cosmetic samples (n=16), including syrups, suspensions, oral sprays, gels, etc. At least one paraben derivative was detected in six samples and was determined quantitatively. The maximum amount of a paraben derivative found in the analyzed samples was 321.7 ng/mL, which was MP. To the best of our knowledge, this is the first LC method, which is applicable both on pharmaceutical and cosmetic samples.

A Simple Method for the Simultaneous Determination of Various Preservatives in Liquid Foods

A direct injection gas chromatography (GC) instrument equipped with an intermediate polar column (CP-SIL 8CB, 30 m × 0.53 mm) was used to determine nine preservatives (including sorbic acid, dehydroacetic acid, benzoic acid, methyl paraben, ethyl paraben, isopropyl paraben, propyl paraben, isobutyl paraben and butyl paraben) in vinegar, soy sauce, pickle condiment liquid and fish sauce. A water soluble compound 1,4-dihydroxybenzene (DHB) was used as an internal standard. The detection limits of the above preservatives were found to be lower than 0.5 ppm. A recovery study was performed by spiking 200 μg target compounds into 1 ml of vinegar or soy sauce and then analyzed by GC. Results showed the recoveries of the above nine preservatives were in the range of 95-106% with coefficients of variation less than 7.2%. These results indicate that the direct injection GC method is an accurate, simple and rapid method to simultaneously screen and quantify sorbic acid, dehydroacetic acid, benzoic acid and six parabens in liquid foods without further sample preparation. Thirty-seven liquid food samples of vinegar, soy sauce, pickle condiment liquid and fish sauce were analyzed using the developed method. The contents of sorbic acid, benzoic acid, dehydroacetic acid, and 6 parabens in vinegar samples were found to be 0-407, 0-519, 0 and 0-102 μg/mL; in soy sauce samples were 0-311, 0-266, 0 and 0-243 μg/mL; in pickle condiment liquid samples were 0-462, 0-3, 0 and 0-209 μg/mL; and in fish sauce samples were 0-1044, 0-266, 0 and 0-163 μg/mL, respectively. Results also showed most of the test samples were fortified with two or more preservatives. Thirteen out of 14 samples labeled "preservative-free" were detected to be preservative containing products. The total preservative contents in some test samples were over the regulation levels of 100 "g/mL in vinegar and 500 "g/mL in soy sauce or fish sauce.

Simultaneous Determination Of Six Parabens In Cosmetics By A New High Performance Liquid Chromatography Method With Fluorescence Detection

In this study, a new high performance liquid chromatography method with fluorescence detection was developed and validated for the simultaneous determination of methyl paraben, ethyl paraben, propyl paraben, isopropyl paraben, butyl paraben and benzyl paraben in cosmetics. Separations were achieved using a C18 guard column (2.1 Ч 10 mm, 3 µm) and a C18 analytical column (2.1 Ч 150 mm, 3 µm). Isocratic elution was applied with a mobile phase consisting of 45 % aqueous o-phosphoric acid solution (0.08 %) and 55 % methanol/water mixture (90 : 10 v/v). The excitation and the emission wavelengths were 254 and 310 nm, respectively. Column temperature was fixed at 40 єC. The linear range was 0.50-10.00 μg/mL for all of the parabens. Limits of detection and quantification were in the range of 0.29-0.32 μg/mL and 0.88-0.97 μg/ mL, respectively. Precision and accuracy values were calculated by analysis results of standard solutions at 0.50, 2.50 and 10.00 μg/mL. The developed and validated method was applied for simultaneous quantitative determination of six paraben species in cosmetic tonic and micellar water samples successfully.

FPSE-HPLC-PDA analysis of seven paraben residues in human whole blood, plasma, and urine

This work describes a new, fast and sensitive method for the simultaneous determination of seven paraben residues including methyl paraben (MPB), ethyl paraben (EPB), propyl paraben (PPB), isopropyl paraben (iPPB), butyl paraben (BPB), isobutyl paraben (iBPB) and benzyl paraben (BzPB) in human whole blood, plasma and urine. The analytes were extracted from the biological matrices by an innovative technique, fabric phase sorptive extraction (FPSE) and subsequently analyzed by high-performance liquid chromatography (HPLC) coupled with photo diode array detector (PDA).The separation was carried out with a Spherisorb C18 column using methanol and phosphate buffer as mobile phases. Ketoprofen was used as the internal standard (IS). The analytical method has been validated according to the International Guidelines in terms of calibration curves for each biological matrix, precision (intra and inter day), trueness, selectivity, LODs, LOQs and ruggedness. Subsequently, the performance of the analytical method was evaluated on real biological samples.The proposed innovative method allows simultaneous analysis of seven paraben residues in three different biological matrices, including whole blood, plasma and urine and therefore it is easily applicable to monitor these substances in different biological samples. Furthermore, extraction technique used in this work is fast, easy to use and in accordance with the modern green analytical chemistry (GAC) principles.

Investigation on Parabens Occurrence in Romanian WWTP Sludge by LC-MS/MS Method

A sensitive and precise method for detection of five parabens in sewage sludge was developed based on ultrasonic assistedextraction, SPE clean-up and LC-MS/MS. Most of the parameters that affect the extraction step such as type of solvent and volume, extraction time were optimized. For ultrasonic extraction it was used a mixture of methanol: acetone, then the extract was centrifuged in order to obtain clean supernatant and the extract was purified on polymericSPE cartridges. The parabens were separated on C18 column in 13 min at 18�C using a gradient of mobile phase of 0.01% acetic acid and acetonitrile. Using the method, limit of quantitation (LOQ) were obtained ranging from 0.4 to 2ng/g. All recoveries ranged from 71% to 109% for all compounds. The repeatability and reproducibility between days expressed as RSD (%) were less than 7.4% and 14.5%, respectively. The sum concentrations of all parabens for each sludge sample ranged between 19 ng/g dry weight and 32.7 ng/g dry weight. The study of the profile sample composition shows that the average contribution of each compound of the total parabens concentration was as follow: methyl paraben 62.9%, ethyl paraben 18.6%, iso-propyl paraben 10.9%, propyl paraben 10.8%. This result indicate that methyl paraben is the most used paraben followed by ethyl paraben.

In vitro genotoxic and cytotoxic effects of some paraben esters on human peripheral lymphocytes

Parabens (PBs) are p-hydroxybenzoic acid ester compounds commonly employed as antimicrobial preservatives, mainly in food, cosmetic, and pharmaceutical products. The aim of the present study was to investigate the genotoxic and cytotoxic effects of some paraben esters (butyl paraben, propyl paraben, isobutyl paraben, and isopropyl paraben) on human peripheral lymphocytes, using in vitro sister chromatid exchange (SCE), chromosome aberration (CA), and cytokinesis-block micronucleus (CBMN) tests. Lymphocyte cultures were treated with four concentrations of PBs (100, 50, 25 and 10 µg/mL) for 24 and 48 h. Paraben esters significantly induced MN formations as compared to solvent control. Furthermore, butyl paraben and propyl paraben increased MN formations a concentration-dependent manner at 24 and 48 h. PBs increased the CA at 24 and 48 h. However, this increase was not meaningful for butyl paraben and isopropyl paraben at 48 h when compared with solvent control. Butyl, isobutyl, and isopropyl paraben significantly increased the SCE at 24 and 48 h. However, propyl paraben did not induce SCE meaningfully in both treatment periods. A significant decrease in the cytokinesis-block proliferation index and mitotic index was observed in cells exposed to all concentrations of PBs at 24 and 48 h. However, proliferation index was not affected at all concentrations of PBs after 24 h treatment, although it was decreased at the highest concentration of PBs at 48 h. It is concluded that all of the paraben esters used in this study have highly genotoxic and cytotoxic effects on human lymphocytes cells in vitro.

Simultaneous determination of nine preservatives in food by liquid chromatography with the aid of coagulant in the clean-up process

ABSTRACTA simple HPLC method was developed for the simultaneous analysis of nine preservatives in food including benzoic acid, sorbic acid, dehydroacetic acid, methyl paraben, ethyl paraben, isopropyl paraben, propyl paraben, isobutyl paraben and butyl paraben. Samples were extracted with 60 v/v% methanol containing poly-aluminium chloride (PAC) and sodium hydroxide prior to analysis. PAC, which is normally used as a coagulant, was successfully applied to remove interfering substances from the samples. The method showed good linearity with coefficients of determination higher than 0.999 over the range of 0.2–5 µg ml–1 for all target preservatives. LOQs of the method were in the range of 0.002–0.008 g kg–1. Method performance was evaluated in a variety of foods demonstrated to have quantitative recoveries of 81.7–102.5% with satisfactory intra-day precision of < 3.7% and inter-day precision of < 6.5%. The method also demonstrated applicability to real foods containing preservatives.

어린이용 화장품에 사용되는 보존제 및 함유량 조사

본 연구에서는 시중에서 유통 중인 어린이용 화장품 총 125건(n = 125)을 대상으로 하여 파라벤 6종과 벤질알콜, 페녹시에탄올, 소르빈산, 벤조산 등 10종의 보존제에 대한 혼합 사용실태와 함량을 HPLC를 이용하여 조사하였다. 유형별 보존제 검출률은 세정제 63%, 크림류 48%, 자외선차단제 46%, 로션류 38%, 오일이 13%의 순으로 검출되어 총 125건 중 63건(50%)의 제품에서 1종류 이상의 보존제를 사용하고 있는 것으로 조사되었다. 보존제별 검출범위는 페녹시에탄올 0.01 ~ 0.91% (n = 35), 벤조산 0.01 ~ 0.48% (n = 28), 벤질알콜 0.01 ~ 0.78% (n = 9), 소르빈산 0.01 ~ 0.11% (n = 3)였으며, 파라벤류 중 메틸 파라벤과 프로필 파라벤은 0.04 ~ 0.21% (n = 8)와 0.02 ~ 0.09% (n = 8)의 검출범위를 보였고, 에틸 파라벤은 1개 제품에서 0.04%로 모두 배합한도 이내로 검출되었다. 조사결과 어린이용 화장품에서는 파라벤류 보다 페녹시에탄올과 벤조산의 사용빈도가 높았으며 검출된 파라벤류 중에서는 메틸 파라벤과 프로필 파라벤이 주로 혼합 사용되는 것으로 나타났다.

Toxicological evaluation of isopropylparaben and isobutylparaben mixture in Sprague–Dawley rats following 28 days of dermal exposure

The alkyl esters of p-hydroxybenzoic acid (Parabens) have been of concern due to their probable endocrine disrupting property especially in baby consumer products. The safety of parabens for use as a preservative in cosmetics has come into controversy, and thus consumer demand for paraben-free products is ever increasing. Thus, more comprehensive studies are needed to conclusively determine the safety of the multiple prolonged exposure to parabens with cosmetic ingredients. This study was conducted to investigate the potential repeated 28 days dermal toxicity (50, 100, 300, or 600 mg/kg bw/day) of isopropylparaben (IPP), isobutylparaben (IBP), or the mixture of IPP and IBP in rats. There were no significant changes in body and organ weights in any group. However, histopathological examinations showed that weak or moderate skin damages were observed in female rats by macroscopic and microscopic evaluations. In female rats, no observed adverse effect levels (NOAELs) of IPP with no skin lesion and IBP for skin hyperkeratosis, were estimated to be 600 mg/kg bw/day, and 50 mg/kg bw/day, respectively. With regard skin hyperkeratosis, the lowest observed adverse effect level (LOAEL) of the mixture of IPP and IBP was estimated to be 50 mg/kg bw/day. Analysis of six serum hormones (estrogen, testosterone, insulin, T3, TSH, or FSH) in animals showed that only FSH was dose-dependently decreased in the mixture groups of 100 mg/kg bw/day or higher. These data suggest that the mixture of IPP and IBP showed a synergistic dermal toxicity in rats and should be considered for future use in consumer products.

Pressurized liquid extraction-gas chromatography-mass spectrometry analysis of fragrance allergens, musks, phthalates and preservatives in baby wipes

Baby wipes and wet toilet paper are specific hygiene care daily products used on newborn and children skin. These products may contain complexes mixtures of harmful chemicals. A method based on pressurized liquid extraction (PLE) followed by gas chromatography-mass spectrometry (GC-MS) has been developed for the simultaneous determination of sixty-five chemical compounds (fragrance allergens, preservatives, musks, and phthalates) in wipes and wet toilet paper for children. These compounds are legislated in Europe according Regulation EC No 1223/2009, being twelve of them banned for their use in cosmetics, and one of them, 3-iodo-2-propynyl butylcarbamate (IPBC), is banned in products intended for children under 3 years. Also, propyl-, and butylparaben will be prohibited in leave-on cosmetic products designed for application on the nappy area of children under 3 years from April 2015. PLE is a fast, simple, easily automated technique, which permits to integrate a clean-up step during the extraction process reducing analysis time and stages. The proposed PLE-based procedure was optimized on real non-spiked baby wipe samples by means of experimental design to study the influence on extraction of parameters such as extraction solvent, temperature, extraction time, and sorbent type. Under the selected conditions, the method was validated showing satisfactory linearity, and intra-day, and inter-day precision. Recoveries were between 80–115% for most of the compounds with relative standard deviations (RSD) lower than 15%. Finally, twenty real samples were analyzed. Thirty-six of the target analytes were detected, highlighting the presence of phenoxyethanol in all analyzed samples at high concentration levels (up to 0.8%, 800μgg−1). Methyl paraben (MeP), and ethyl paraben (EtP) were found in 40-50% of the samples, and the recently banned isobutyl paraben (iBuP) and isopropyl paraben (iPrP), were detected in one and seven samples, respectively, at concentrations between 0.093 and 247μgg−1. In the case of phthalates, the forbidden phthalates dibutyl phtalate (DBP) and di(2-ethylhexyl)phthalate (DEHP) were also found in thirteen samples at low levels. All the samples contained fragrance allergens in many cases at high levels (up to 2400μgg−1) and three musks were detected in the samples. Excluding the banned compounds, all samples complied with the concentration limits established by the European Regulation although 25% of them did not fulfill the labeling requirements for fragrance allergens.

Synergistic effects of parabens on the induction of calbindin-D9k gene expression act via a progesterone receptor-mediated pathway in GH3 cells

Although the endocrine-disrupting bioactivity of parabens is weakly estrogenic (parabens are xenoestrogens), their combined synergistic effect is unknown. The aim of this study was to investigate the effects of methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP), isopropyl paraben (IPP), butyl paraben (BP), and isobutyl paraben (IBP), either alone or in combination (MP + EP + PP + BP; PP + IPP; and BP + IBP) on the induction of the estrogenic biomarker gene, calbindin-D(9k) (CaBP-9k), in rat pituitary lactosomatotrophic GH3 cells. The expression of CaBP-9k mRNA and protein was analyzed using real-time PCR and Western blot analysis, respectively. After 24 h of treatment, a significant increase in CaBP-9k expression was observed. This was dependent upon the length of the paraben alkyl chains (shortest in MP and longest in IBP). Interestingly, the synergistic effects of these paraben combinations were observed at a dose (10(-5) M) of these parabens, which induced the highest expression of CaBP-9k mRNA and protein. To investigate the involvement of estrogen receptors (ERs) and progesterone receptors (PRs), through which parabens exert their effects, the expression levels of ERα and PR-B were also examined. The expression of ERα mRNA and protein fluctuated after paraben treatment in GH3 cells, which was not significant. However, the expression level of ERα gene was induced when cotreated with 17β-estradiol (E2) and ICI 182, 780 (estrogen receptor antagonist). The different combinations of parabens induced the expression of the PR-B gene, which was abolished by cotreatment with ICI 182,780. The expression patterns of CaBP-9k and PR-B genes appeared to be similar in response to paraben treatments. This implied that CaBP-9k expression in GH3 cells may be induced by parabens via a PR-mediated pathway. Taken together, these results suggest that exposure to multiple parabens at low concentrations may increase their synergistic estrogenic activities in GH3 cells through a PR-mediated pathway.