Assessment of immunomodulatory effects of five commonly used parabens on human THP-1 derived macrophages: Implications for ecological and human health impacts.

Parabens are widely used as broad-spectrum anti-microbials and preservatives in food, cosmetics, pharmaceuticals, and personal care products. Studies suggest that the utilization of parabens has substantially increased over the past years, particularly during the global pandemic of coronavirus disease 2019 (COVID-19). Although parabens are generally recognized as safe by the U.S. FDA, some concerns have been raised regarding the potential health effects of parabens associated with immunotoxicity. Herein, we comprehensively investigated several key characteristics of immunotoxicants of five commonly used parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl parabens) in human THP-1 derived macrophages, which are effector cells serving as a first line of host defense against pathogens and tumor immunosurveillance. The results indicate parabens, at concentrations found in humans and biota, significantly dampened macrophage chemotaxis and secretion of major pro-inflammatory cytokines (TNF-α and IL-6) and anti-inflammatory cytokine (IL-10), corroborating the mRNA expression profile. Furthermore, some parabens were found to markedly alter macrophage adhesion and cell surface expression of costimulatory molecules, CD80+ and CD86+, and significantly increase macrophage phagocytosis. Collectively, these findings heighten awareness of potential immunotoxicity posed by paraben exposure at biologically relevant concentrations, providing implications for human health and ecological risks associated with immune dysfunctions.

Butylparaben induces glycolipid metabolic disorders in mice via disruption of gut microbiota and FXR signaling.

Butylparaben, a common preservative, is widely used in food, pharmaceuticals and personal care products. Epidemiological studies have revealed the close relationship between butylparaben and diabetes; however the mechanisms of action remain unclear. In this study, we administered butylparaben orally to mice and observed that exposure to butylparaben induced glucose intolerance and hyperlipidemia. RNA sequencing results demonstrated that the enrichment of differentially expressed genes was associated with lipid metabolism, bile acid metabolism, and inflammatory response. Western blot results further validated that butylparaben promoted hepatic lipogenesis, inflammation, gluconeogenesis, and insulin resistance through the inhibition of the farnesoid X receptor (FXR) pathway. The FXR agonists alleviated the butylparaben-induced metabolic disorders. Moreover, 16 S rRNA sequencing showed that butylparaben reduced the abundance of Bacteroidetes, S24-7, Lactobacillus, and Streptococcus, and elevated the Firmicutes/Bacteroidetes ratio. The gut microbiota dysbiosis caused by butylparaben led to decreased bile acids (BAs) production and increased inflammatory response, which further induced hepatic glycolipid metabolic disorders. Our results also demonstrated that probiotics attenuated butylparaben-induced disturbances of the gut microbiota and hepatic metabolism. Taken collectively, the findings reveal that butylparaben induced gut microbiota dysbiosis and decreased BAs production, which further inhibited FXR signaling, ultimately contributing to glycolipid metabolic disorders in the liver.

Enhanced oxidation of parabens in an aqueous solution by air-assisted cold plasma.

Various contaminants of emerging concern (CECs) including pharmaceuticals and personal care products (PPCPs) have been known to threaten the aquatic ecosystem and human health even at low levels in surface water. Among them, the wide variety use of parabens as preservatives may pose potential threat to human because parabens may present estrogenic activity. Various advanced oxidation processes have been attempted to reduce parabens, but challenges using cold plasma (CP) are very rare. CP is worth paying attention to in reducing parabens because it has the advantage of generating radical ions, including reactive oxygen/nitrogen species and various ions. Accordingly, this study demonstrates how CP can be utilized and how CP competes with other advanced oxidation processes in energy requirements. Quantified ethyl-, propyl-, and butyl-paraben indicate that CP can effectively degrade them up to 99.1% within 3 h. Regression reveals that the kinetic coefficients of degradation can be increased to as high as 0.0328 min-1, comparable to other advanced oxidation processes. Many by-products generated from the oxidation of parabens provide evidence of the potential degradation pathway through CP treatment. In addition, we found that the electrical energy consumption per order of CP (39-95 kWh/m3/order) is superior to other advanced oxidation processes (69∼31,716 kWh/m3/order). Overall, these results suggest that CP may be a viable option to prevent adverse health-related consequences associated with parabens in receiving water.

Preservative contact allergy in occupational dermatitis: a machine learning analysis.

Occupational dermatoses impose a significant socioeconomic burden. Allergic contact dermatitis related to occupation is prevalent among healthcare workers, cleaning service personnel, individuals in the beauty industry and industrial workers. Among risk factors, the exposure to preservatives is frequent, since they are extensively added in products for occupational use. The goal of this study is to investigate the contact allergy patterns in order to understand the linkage among hypersensitivity to preservatives, occupational profiles, patients' clinical and demographic characteristics. Patch test results were collected from monosensitized patients to Formaldehyde 2%, KATHON 0.02%, thimerosal 0.1%, and MDBGN 0.5%; information was also collected for an extended MOAHLFA (Male-Occupational-Atopic-Hand-Leg-Face-Age) index. To assess the relationship between allergen group and occupational-related ACD, the chi-square test for independence was utilized. To uncover underlying relationships in the data, multiple correspondence analysis (MCA) and categorical principal components analysis (CATPCA), which are machine learning approaches, were applied. Significant relationships were found between allergen group and: occupation class, atopy, hand, leg, facial, trunk, neck, head dermatitis, clinical characteristics, ICDRG 48 h and ICDRG 72 h clinical evaluation. MCA and CATPCA findings revealed a link among allergen group, occupation class, patients' demographic and clinical characteristics, the MOAHLFA index, and the ICDRG scores. Significant relationships were identified between the allergen group and various manifestations of dermatitis. The utilization of machine learning techniques facilitated the discernment of meaningful patterns in the data.

Multiple use of preservative-free single dose unit dexamethasone 0.1% eye drops is safe within 24 hours.

BACKGROUND: Unpreserved single-dose unit (SDU) eye drops are commonly used to avoid benzalkonium chloride-related toxicity. Although intended for single use, many patients report off-label repeated use of SDUs over a prolonged period. We investigated whether repeated use of dexamethasone 0.1% SDUs in the same patient increases the bacterial contamination rate. METHODS: We prospectively enrolled patients scheduled for inpatient corneal and glaucoma surgery receiving dexamethasone 0.1% SDU four times per day from the same vial. To assess contamination rates, one drop from the vial was cultured immediately after opening the SDU (t0), 10 hours later after four drop applications (t10) and 24 hours after opening without further drop applications (t24). Conjunctival swabs were taken before and after drop application. Contamination rate was assessed with a standard clinical culturing protocol without introducing a positive control. RESULTS: 110 eyes of 109 patients were evaluated. Drops collected immediately after opening the SDU (t0) were contaminated in 9/110 cultures (8.1%). At t10, 13/110 cultures were contaminated (11.8%; p=0.267) and 11/110 at t24 (10.0%; t24 vs t0; p=1.00). In 5 of 21 cases of contaminated drops at t10 and/or t24, the same isolates were cultured from the initial conjunctival swab and the SDU. In three cases, the same bacterial species was found in consecutive samples. CONCLUSION: The contamination rate of the SDU did not increase after multiple use within 24 hours. Contamination from fingertip flora was more likely than from ocular surface flora. Reuse of dexamethasone 0.1% SDU in the same patient within 24 hours appears to be safe.

Contact sensitization and self-reported eczema in Swedish painters with occupational exposure to isothiazolinones.

BACKGROUND: Due to an increasing occupational usage of isothiazolinone (IT)-containing preservatives, and their potential to cause skin sensitization and allergic contact dermatitis, that is, chronic disease, there is a need for more knowledge on how highly exposed workers are affected. OBJECTIVES: The overall objective was to explore dermatological symptoms of potentially long-lasting or chronic character in Swedish painters. METHODS: Building painters from western and southern Sweden were initially invited to perform a questionnaire on occurrence of skin symptoms. Participants with affirmative responses, and the right inclusion criteria, were further invited to patch testing with four different ITs: benzisothiazolinone (BIT), methylisothiazolinone, methylchloroisothiazolinone and octylisothiazolinone. RESULTS: There was a tendency towards higher occurrence of positive patch test reactions among the painters compared with occupationally unexposed registry patients; however, not statistically significant differences. BIT was the substance most frequently causing positive test results in both groups. The occurrence of adult-onset eczema was higher in painters than in the control group of electricians, and just shy of statistical significance concerning any of several skin locations (face/legs/arms/hands). CONCLUSION: Building painters present with positive patch test reactions to common paint preservatives (ITs), and they report adult-onset eczema more often than do less occupationally exposed groups.

The influence of Leucidal, a natural cosmetic preservative, on fibroblast and keratinocytes. Studies on cells and on model membrane systems.

The aim of this work was to investigate the influence of Leucidal® Liquid (abbr. Leucidal), which is recommended as a natural cosmetic ingredient of antimicrobial properties, on model membranes of keratinocytes and fibroblasts. The toxicity tests on cell lines were also performed to allow for a more detailed discussion of the results. As model membrane systems the lipid Langmuir monolayers were applied. During the investigations, the surface pressure/area measurements, penetration studies and Brewster Angle Microscopy (BAM) visualization were performed for one component and mixed lipid monolayers. It was evidenced that at the membrane - corresponding conditions, the components of Leucidal do not penetrate either model keratinocyte and fibroblast membranes or one component films composed of the major lipids of skin cell membranes. Leucidal makes these systems slightly more expanded and less stable, however this is not reflected in the changes in the film morphology. Only the ceramide systems were sensitive to the presence of Leucidal, i.e. the incorporation of Leucidal components manifested well in the decrease of the films' condensation and alterations in their morphology. The tests on cells demonstrated that Leucidal is non toxic for these types of cells at the concentrations suggested by the producer. A thorough comparison of these results with those published for bacteria model membranes enabled us to discuss them in the context of the mechanism of action of Leucidal components. It was concluded that Leucidal components are of low affinity to the skin cellular model membranes of low content of Leucidal-sensitive ceramides and are not toxic for fibroblast and keratinocyte cell lines. Moreover, the lipid composition of the membrane and its molecular organization can be important targets for Leucidal components, decisive from the point of view of the activity and selectivity of the studied composition.

[Translated article] Physicochemical and microbiological stability study of two new preservative-free methylprednisolone eye drops.

OBJECTIVE: To study the physicochemical and microbiological stability over 90 days of two preservative-free methylprednisolone sodium succinate (MTPSS) 1 and 10 mg/mL eye drops for use in ocular pathologies such as Sjögren's syndrome and dry eye syndrome. METHOD: The two eye drops were prepared from injectable MTPSS (Solu-moderin® and Urbason®), water for injection and normal saline solution. In accordance with ICH (International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use) guidelines, they were then stored in triplicate under refrigerated conditions (5±3 °C), at room temperature (25±2 °C), and at 40 °C (±2 °C). In accordance with the USP (United States Pharmacopeia), physicochemical controls of the active ingredient content were carried out by HPLC-UV (High Performance Liquid Chromatography with Ultraviolet detection), together with controls of pH, osmolality, and visual examination. Microbiological sterility was also tested under refrigerated conditions up to 30 days in open containers and up to 90 days in closed ones. RESULTS: The eye drops stored at 5 °C were the most stable; in the 1 mg/mL eye drops, degradation of the drug fell below 90% from day 21, and in the 10 mg/mL eye drops, from day 42. pH change did not vary by ≥1 unit in formulations stored at 5 °C, unlike the other formulations. Changes in osmolality did not exceed 5% on day 90 in any storage conditions. Samples of non refrigerate eye drops at 10 mg/mL, presented a white precipitate from day 14 and 28, respectively. Non-refrigerated 1 mg/mL eye drops presented suspended particles on day 90. There were no color changes. Microbiological analysis showed that sterility was maintained for over 90 days in the closed containers, although microbial contamination was detected from day 21 in the open containers. CONCLUSIONS: 1 mg/mL MTPSS eye drops show physicochemical and microbiological stability for 21 days under refrigeration, compared to 42 days for 10 mg/mL eye drops stored under the same conditions. However, since they do not include preservatives in their composition, they should not be used for more than 7 days after opening.

Association between parabens exposure and neurodevelopment in children.

OBJECTIVE: Parabens are a group of substances commonly employed as antimicrobial preservatives. The effect of parabens on the development of neurotoxicity in children is still controversial. This study aimed to explore the associations between parabens exposure and children's neurodevelopmental performance, emphasizing potential sex differences and the combined effects of parabens. METHODS: We used the long-term follow-up study of Taiwanese generation, Taiwan Birth Panel Study II (TBPS II). We recruited the group of children at 6-8 years old. And, we measured parabens in children urine, including methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP). Children's attention-related performance was evaluated using the Conners Kiddie Continuous Performance Test 2nd Edition (K-CPT 2). The study employed both linear regression and mixture analysis quantile g-computation (QGC) methods to discern associations. A stratified analysis by sex and QGC was implemented to delve deeper into the cumulative effects of parabens. RESULTS: A total of 446 subjects completed both the parabens analysis and the K-CPT 2 survey. The overall association between parabens and neurodevelopmental performance was not pronounced, but discernible sex differences emerged. In the single pollutant analysis, elevated PP concentrations were associated with higher K-CPT 2 scores particularly in detectability (d') (ß = 0.92 [95 % CI = 0.15 to 1.69]) and commissions (ß = 0.95 [95 % CI = 0.12 to 1.78]), among girls. Further, in the mixture analysis, a significant association between PP and detectability (d') was observed in girls (ß = 1.68 [95 % CI = 0.11 to 3.26]). CONCLUSIONS: This study identified sex-specific associations between parabens and attention performance. Consistent outcomes across single and mixture analysis methods. Further research is crucial to clarify these causal associations.

Integrated high-throughput drug screening microfluidic system for comprehensive ocular toxicity assessment.

Traditional experimental methodologies suffer from a few limitations in the toxicological evaluation of the preservatives added to eye drops. In this study, we overcame these limitations by using a microfluidic device. We developed a microfluidic system featuring a gradient concentration generator for preservative dosage control with microvalves and micropumps, automatically regulated by a programmable Arduino board. This system facilitated the simultaneous toxicological evaluation of human corneal epithelial cells against eight different concentrations of preservatives, allowing for quadruplicate experiments in a single run. In our study, the IC50 values for healthy eyes and those affected with dry eyes syndrome showed an approximately twofold difference. This variation is likely attributable to the duration for which the preservative remained in contact with corneal cells before being washed off by the medium, suggesting the significance of exposure time in the cytotoxic effect of preservatives. Our microfluidic system, automated by Arduino, simulated healthy and dry eye environments to study benzalkonium chloride toxicity and revealed significant differences in cell viability, with IC50 values of 0.0033% for healthy eyes and 0.0017% for dry eyes. In summary, we implemented the pinch-to-zoom feature of an electronic tablet in our microfluidic system, offering innovative alternatives for eye research.

Influence of Surfactant on the Skin Permeation of Methylisothiazolinone and Methylchloroisothiazolinone.

Patch tests are often used in safety evaluations to identify the substance causing skin irritation, but the same substance can sometimes give positive or negative results depending on the test conditions. Here, we investigated differences in the skin penetration of two test compounds under different application conditions. We studied the effects of the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant polysorbate 80 (PS) on skin penetration of the preservatives methylisothiazolinone (MT) and methylchloroisothiazolinone (MCT), which are used in cosmetics such as shampoos. The skin permeation of MT was enhanced by SDS but was unchanged by PS. Skin impedance decreased in the presence of SDS whereas PS had the same effect as the control aqueous solution, suggesting that SDS reduction of the barrier function of skin affects the permeation of MT, a hydrophilic drug. Application of a mixture of MCT and MT in the presence of SDS did not affect the skin permeation of MCT whereas the permeation of MT was enhanced by SDS, indicating that the skin permeation of MCT is less affected by SDS than is MT. Thus, attention should be paid to the possible effect of co-solutes, especially hydrophilic drugs.

Preservative-Free Fixed Combination of Tafluprost 0.0015% and Timolol 0.5% for Treatment-Naive Patients with Open-Angle Glaucoma.

PURPOSE: To assess efficacy, safety, and tolerability of the preservative-free (PF) fixed-dose combination (FC) of tafluprost 0.0015%/timolol 0.5% (PF tafluprost/timolol FC) in treatments-naive patients with primary open-angle glaucoma (POAG). METHODS: This was a retrospective, real-world clinical practice setting study that included 107 eyes of 107 subjects with POAG who had never been treated for glaucoma. All subjects were received PF tafluprost/timolol FC once daily. Intraocular pressure (IOP) levels were documented for each eye at the untreated baseline and up to 6 months after the initiation of medical treatment. All adverse events, including ocular and systemic adverse reactions, were recorded. Additionally, the reasons for medication discontinuations were thoroughly documented. RESULTS: A total of 32 POAG patients with high-baseline IOP (>21 mmHg) and 75 with normal-baseline IOP were included in the study. The subjects' baseline mean age was 62.4 ± 8.7 years (range, 26.0-85.0 years); among them, 42 were female (39.3%). Mean IOP at baseline for all patients was 18.6 ± 4.3 mmHg. The mean IOP at 6 months was 12.6 ± 4.7 mmHg, representing a significant decrease compared to the baseline (-32%, p < 0.001). In POAG patients with high-baseline IOP, mean IOP was significantly lowered from 28.0 ± 5.7 mmHg at baseline to 18.0 ± 5.5 mmHg (-35%, p < 0.001); in patients with normal-baseline IOP, from 14.6 ± 3.4 mmHg at baseline to 10.3 ± 4.1 mmHg (-29%, p < 0.001). PF tafluprost/timolol FC was well-tolerated and safe. After 6 months, 97.2% of all patients remained on therapy. CONCLUSIONS: In this real-world observational study, once-daily treatment with PF tafluprost/timolol FC demonstrated clinically relevant and statistically significant efficacy, as well as safety and good tolerability, in treatment-naive patients diagnosed with POAG.

Physicochemical and microbiological stability study of two new preservative-free methylprednisolone eye drops. / Estudio de estabilidad fisicoquímica y microbiológica de dos nuevos colirios de metilprednisolona sin conservantes.

OBJECTIVE: To study the physicochemical and microbiological stability over 90 days of two preservative-free methylprednisolone sodium succinate (MTPSS) 1 mg/ml and 10 mg/ml eye drops for use in ocular pathologies such as Sjögren's syndrome and dry eye syndrome. METHOD: The two eye drops were prepared from injectable MTPSS (Solu-moderin® and Urbason®), water for injection and normal saline solution. In accordance with ICH (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) guidelines, they were then stored in triplicate under refrigerated conditions (5 ±3 °C), at room temperature (25 ± 2 °C), and at 40 °C (±2 °C). In accordance with the USP (United States Pharmacopeia), physicochemical controls of the active ingredient content were carried out by HPLC-UV (High Performance Liquid Chromatography with Ultraviolet detection), together with controls of pH, osmolality, and visual examination. Microbiological sterility was also tested under refrigerated conditions up to 30 days in open containers and up to 90 days in closed ones. RESULTS: The eye drops stored at 5 °C were the most stable; in the 1 mg/ml eye drops, degradation of the drug fell below 90% from day 21, and in the 10 mg/ml eye drops, from day 42. pH change did not vary by ≥1 unit in formulations stored at 5 °C, unlike the other formulations. Changes in osmolality did not exceed 5% on day 90 in any storage conditions. Samples of non refrigerate eye drops at 10 mg/ml, presented a white precipitate from day 14 and 28 respectively. Non-refrigerated 1 mg/ml eye drops presented suspended particles on day 90. There were no color changes. Microbiological analysis showed that sterility was maintained for over 90 days in the closed containers, although microbial contamination was detected from day 21 in the open containers. CONCLUSIONS: 1 mg/ml MTPSS eye drops show physicochemical and microbiological stability for 21 days under refrigeration, compared to 42 days for 10 mg/ml eye drops stored under the same conditions. However, since they do not include preservatives in their composition, they should not be used for more than 7 days after opening.

Repeated-dose toxicity and toxicokinetic study of isobutylparaben in rats subcutaneously treated for 13 weeks.

Parabens have historically served as antimicrobial preservatives in a range of consumables such as food, beverages, medications, and personal care products due to their broad-spectrum antibacterial and antifungal properties. Traditionally, these compounds were believed to exhibit low toxicity, causing minimal irritation, and possessing limited sensitization potential. However, recent evidence suggests that parabens might function as endocrine-disrupting chemicals (EDCs). Consequently, extensive research is underway to elucidate potential human health implications arising from exposure to these substances. Among these parabens, particular concerns have been raised regarding the potential adverse effects of iso-butylparaben (IBP). Studies have specifically highlighted its potential for inducing hormonal disruption, significant ocular damage, and allergic skin reactions. This study aimed to evaluate the prolonged systemic toxicity, semen quality, and estrus cycle in relation to endocrine disruption endpoints, alongside assessing the toxicokinetic behavior of IBP in Sprague-Dawley rats following a 13-week repeated subcutaneous administration. The rats were administered either the vehicle (4% Tween 80) or IBP at dosage levels of 2, 10, and 50 mg/kg/day for 13 weeks. Blood collection for toxicokinetic study was conducted on three specified days: day 1 (1st), day 30 (2nd), and day 91 (3rd). Systemic toxicity assessment and potential endocrine effects were based on various parameters including mortality rates, clinical signs, body weights, food and water consumption, ophthalmological findings, urinalysis, hematological and clinical biochemistry tests, organ weights, necropsy and histopathological findings, estrus cycle regularity, semen quality, and toxicokinetic behavior. The findings revealed that IBP induced local irritation at the injection site in males at doses ≥ 10 mg/kg/day and in females at 50 mg/kg/day; however, systemic toxicity was not observed. Consequently, the no-observed-adverse-effect level (NOAEL) for IBP was determined to be 50 mg/kg/day in rats of both sexes, indicating no impact on the endocrine system. The toxicokinetics of IBP exhibited dose-dependent systemic exposure, reaching a maximum dose of 50 mg/kg/day, and repeated administration over 13 weeks showed no signs of accumulation.

The new preservative-free ophthalmic formulation of bilastine 0.6% preserves the ocular surface epithelial integrity in a comparative in vitro study.

Allergic conjunctivitis (AC) is the most common form of allergic eye disease and an increasingly prevalent condition. Topical eye drop treatments are the usual approach for managing AC, although their impact on the ocular surface is not frequently investigated. The aim of this study was to perform a comparative physicochemical characterization, and in vitro biological evaluations in primary conjunctival and corneal epithelial cells of the new multidose preservative-free bilastine 0.6% and main commercially available eye drops. MTT assay was used to measure cell viability; oxidative stress was analyzed with a ROS-sensitive probe; and apoptosis was evaluated monitoring caspase 3/7 activation. Differences in pH value, osmolarity, viscosity and phosphate levels were identified. Among all formulations, bilastine exhibited pH, osmolarity and viscosity values closer to tear film (7.4, 300 mOsm/l and ~ 1.5-10 mPa·s, respectively), and was the only phosphates-free solution. Single-dose ketotifen did not induce ROS production, and single-dose azelastine and bilastine only induced a mild increase. Bilastine and single-dose ketotifen and azelastine showed high survival rates attributable to the absence of preservative in its formulation, not inducing caspase-3/7-mediated apoptosis after 24 h. Our findings support the use of the new bilastine 0.6% for treating patients with AC to preserve and maintain the integrity of the ocular surface.

The combined effects of preservative chemicals in consumer products: An analysis using embryonic and adult zebrafish.

Benzisothiazolinone (BIT) and propyl paraben (PP) are preservatives in cleaning products; however, their toxicities are not well understood. In this study, zebrafish embryos were exposed to BIT, PP, and mixtures of both for 96 h to investigate the effects on growth hormone (GH), insulin-like growth factor-1 (IGF-1), and the transcription of 19 genes related to the GH/IGFs axis. Concentrations of BIT and PP were measured in the whole body of larvae. Zebrafish pairs were also exposed to BIT, PP, and mixtures for 21 d to evaluate the effects on sex hormones, histology in gonad, and transcription of 22 genes related to the hypothalamus-pituitary-gonad axis and vitellogenin. The mixtures had potentiation effects on development, reproduction, hormones, and gene transcripts than individual exposure. Larvae exposed to 229 µg L-1 BIT, 64.5 µg L-1 PP, and mixtures showed reduced growth. Decreased GH and IGF-1 levels were supported by gene regulation associated with the GH/IGFs axis. In larvae, reactive oxygen species, superoxide dismutase, catalase, and glutathione peroxidase levels were increased under all exposures. The gonadosomatic index in males and number of eggs decreased after mixture exposure. In females exposed to mixtures, the percentage of atretic follicle in ovary was significantly increased. The significant decrease in testosterone in males and significant decrease in 17ß-estradiol in females exposed to mixtures suggest anti-estrogenic and anti-androgenic potential. Thus, preservative mixtures in consumer products may be more toxic than the individual substances, which is important for managing the risks of mixing preservatives.

Preservative-Free Bimatoprost 0.01% Ophthalmic Gel for Glaucoma Therapy: A Phase III Randomized Controlled Trial.

PRCIS: Noninferiority of efficacy was demonstrated for a preservative-free bimatoprost 0.01% compared with BAK-containing bimatoprost 0.01% following a 12-week treatment period in patients with open angle glaucoma or ocular hypertension. Improved tolerability, in particular conjunctival hyperemia, was also observed. PURPOSE: To evaluate the intraocular pressure (IOP)-lowering efficacy and safety of a preservative-free bimatoprost 0.01% ophthalmic gel (PFB 0.01% gel) compared with preserved bimatoprost 0.01% (PB 0.01%). DESIGN: Phase III, international, multicenter, randomized, 2-parallel group, investigator-masked, 3-month treatment duration. METHODS: Patients with glaucoma or ocular hypertension were randomized after a 7-week run-in/washout period to receive once-daily PFB 0.01% gel (n=236) or PB 0.01% (n=249) for 3 months. The primary efficacy measure was changed from baseline in IOP at week 12. Safety measures included adverse events (AEs) and assessment of conjunctival hyperemia. RESULTS: The mean changes from baseline in IOP at week 12 in the PFB 0.01% gel and PB 0.01% were -9.72±2.97 and -9.47±3.06 mm Hg, respectively, at 8 am , -9.41±3.03 and -9.19±3.12 mm Hg at 10 am , and -8.99±3.36 and -8.54±3.44 mm Hg at 4 pm . Noninferiority of PFB 0.01% gel to PB 0.01% was demonstrated at week 12 based on predetermined criteria (upper 95% CI margin of 1.5 mmHg at all time points). The most frequently reported AE was conjunctival hyperemia; 13 (5.5%) patients with PFB 0.01% gel and 17 (6.8%) patients with PB 0.01%. The percentage of patients experiencing a worsening from baseline in conjunctival hyperemia score was lower with PFB 0.01% gel compared to PB 0.01% at week 6 (20.1% vs. 29.3%, respectively) and week 12 (18.3% vs. 30.4%, respectively). CONCLUSIONS: PFB 0.01% ophthalmic gel has the same efficacy in lowering IOP as PB 0.01% and demonstrated less aggravation of conjunctival hyperemia at weeks 6 and 12.

Analysis of preservatives and fragrances in topical medical devices: The need for more stringent regulation.

INTRODUCTION: Medical devices (MDs) have a long history of use, and come with regulatory frameworks to ensure user safety. Although topically applied MDs in the form of gels and creams might be used on damaged skin, their composition is often similar to that of cosmetic products applicable to intact skin, especially in terms of preservatives and fragrances. However, unlike cosmetics, these products are not subject to compound-specific restrictions when used in MDs. OBJECTIVE: This study aimed to identify and quantify preservatives and fragrances in topically applied MDs and assess their safety towards the Cosmetic Regulation (EC) 1223/2009. METHOD: Sixty-nine MDs available on the EU market were subjected to previously validated liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) methods to identify and quantify occurring preservatives and fragrances. RESULTS: Findings revealed that 32% of the examined MDs did not provide comprehensive ingredient lists, leaving users uninformed about potential risks associated with product use. Furthermore, 30% of these MDs would not meet safety standards for cosmetic products and, most significantly, 13% of the analysed samples contained ingredients that are prohibited in leave-on cosmetics. CONCLUSION: Results highlight the pressing demand for more stringent requirements regarding the labelling and composition of MDs to enhance patient safety. Improved regulation and transparency can mitigate potential risks associated with the use of topically applied MDs.

Mass-Spectrometry-Based Research of Cosmetic Ingredients.

Cosmetic products are chemical substances or mixtures used on the skin, hair, nails, teeth, and the mucous membranes of the oral cavity, whose use is intended to clean, protect, correct body odor, perfume, keep in good condition, or change appearance. The analysis of cosmetic ingredients is often challenging because of their huge complexity and their adulteration. Among various analytical tools, mass spectrometry (MS) has been largely used for compound detection, ingredient screening, quality control, detection of product authenticity, and health risk evaluation. This work is focused on the MS applications in detecting and quantification of some common cosmetic ingredients, i.e., preservatives, dyes, heavy metals, allergens, and bioconjugates in various matrices (leave-on or rinse-off cosmetic products). As a global view, MS-based analysis of bioconjugates is a narrow field, and LC- and GC/GC×GC-MS are widely used for the investigation of preservatives, dyes, and fragrances, while inductively coupled plasma (ICP)-MS is ideal for comprehensive analysis of heavy metals. Ambient ionization approaches and advanced separation methods (i.e., convergence chromatography (UPC2)) coupled to MS have been proven to be an excellent choice for the analysis of scented allergens. At the same time, the current paper explores the challenges of MS-based analysis for cosmetic safety studies.

Estrogenic disruption effects and formation mechanisms of transformation products during photolysis of preservative parabens.

The ubiquitous presence of emerging contaminants (ECs) in the environment and their associated adverse effects has raised concerns about their potential risks. The increased toxicity observed during the environmental transformation of ECs is often linked to the formation of their transformation products (TPs). However, comprehension of their formation mechanisms and contribution to the increased toxicity remains an unresolved challenge. To address this gap, by combining quantum chemical and molecular simulations with photochemical experiments in water, this study investigated the formation of TPs and their molecular interactions related to estrogenic effect using the photochemical degradation of benzylparaben (BZP) preservative as a representative example. A non-targeted analysis was carried out and three previously unknown TPs were identified during the transformation of BZP. Noteworthy, two of these novel TPs, namely oligomers BZP-o-phenol and BZP-m-phenol, exhibited higher estrogenic activities compared to the parent BZP. Their IC50 values of 0.26 and 0.50 µM, respectively, were found to be lower than that of the parent BZP (6.42 µM). The binding free energies (ΔGbind) of BZP-o-phenol and BZP-m-phenol (-29.71 to -23.28 kcal·mol-1) were lower than that of the parent BZP (-20.86 kcal·mol-1), confirming their stronger binding affinities toward the estrogen receptor (ER) α-ligand binding domain. Subsequent analysis unveiled that these hydrophobic residues contributed most favorably to ER binding, with van der Waals interactions playing a significant role. In-depth examination of the formation mechanisms indicated that these toxic TPs primarily originated from the successive cleavage of ester bonds (OCH2C6H5 and COO group), followed by their combination with BZP*. This study provides valuable insight into the mechanisms underlying the formation of toxic TPs and their binding interactions causing the endocrine-disrupting effects. It offers a crucial framework for elucidating the toxicological patterns of ECs with similar structures.