A comparative study of the in vitro dermal absorption of radiolabeled benzophenone through human skin.

Octocrylene is a common sun filter ingredient used to protect the skin from damaging UV rays. Benzophenone is an impurity found in formulations containing octocrylene. [14C]-Benzophenone was spiked (0.1 g/L) into 2 commercial sunscreen formulations; Neutrogena® Beach Defense Sunscreen Spray Broad Spectrum SPF 70 Aerosol, Neutrogena® Ultra Sheer Body Mist Sunscreen Broad Spectrum SPF 30 Aerosol, and an acetone vehicle. The formulations were applied (ca 2 µL/cm2) to dermatomed human skin mounted in static diffusion cells in vitro. Receptor fluid was collected up to 24 h post dose. All samples were analyzed by liquid scintillation counting. The dermal delivery of [14C]-Benzophenone was 10.02, 9.04 and 5.19% for the 3 formulations. However, the [14C]-Benzophenone mass balances were low; 81.5, 85.3 and 8.02%, respectively. A volatility test was performed replacing skin with aluminum foil for the sunscreen formulations only. The [14C]-Benzophenone mass balance at dosing was 99% but fell to 56.9 and 60.6% at 24 h post dose, confirming the losses were due to [14C]-Benzophenone volatility. A conservative dermal absorption value of 12.42% was proposed to cover [14C]-Benzophenone containing formulations.

Preclinical and clinical studies to evaluate cutaneous biodistribution, safety and efficacy of UV filters encapsulated in mesoporous silica SBA-15.

Innovative technologies have been designed to improve efficacy and safety of chemical UV filters. Encapsulation can enhance efficacy and reduce transdermal permeation and systemic exposure. The aims of this work were (i) to determine the cutaneous biodistribution of avobenzone (AVO), oxybenzone (OXY), and octyl methoxycinnamate (OMC) incorporated in mesoporous silica SBA-15 and (ii) to perform preclinical (in vitro) and (iii) clinical safety studies to demonstrate their innocuity and to evaluate sun protection factor (SPF) in humans. Skin penetration studies showed that deposition of OXY and AVO in porcine and human skin after application of stick formulation with incorporated filters (stick incorporated filters) was significantly lower than from a marketed (non-encapsulated) stick. Cutaneous deposition and transdermal permeation of OXY in and across human skin were 3.8-and 13.4- fold lower, respectively, after application of stick entrapped filters. Biodistribution results showed that encapsulation in SBA-15 decreased AVO and OXY penetration reaching porcine and human dermis. Greater deposition (and permeation) of OXY in porcine skin than in human skin, pointed to the role of follicular transport. Stick incorporated filters had good biocompatibility in vivo and safety profiles, even under sun-exposed conditions. Entrapment of UV filters improved the SPF by 26% and produced the same SPF profile as a marketed stick. Overall, the results showed that SBA-15 enabled safety and efficacy of UV filters to be increased.

Application of a PBPK model to elucidate the changes of systemic and liver exposures for rosuvastatin, carotegrast, and bromfenac followed by OATP inhibition in monkeys.

The impact of organic anion-transporting polypeptide (OATP) inhibition on systemic and liver exposures of three OATP substrates was investigated in cynomolgus monkeys. A monkey physiologically-based pharmacokinetic (PBPK) model was constructed to describe the exposure changes followed by OATP functional attenuation. Rosuvastatin, bromfenac, and carotegrast were administered as a single intravenous cassette dose (0.5 mg/kg each) in monkeys with and without predosing with rifampin (RIF; 20 mg/kg) orally. The plasma exposure of rosuvastatin, bromfenac, carotegrast, and OATP biomarkers, coproporphyrin I (CP-I) and CP-III were increased 2.3, 2.1, 9.1, 5.4, and 8.8-fold, respectively, when compared to the vehicle group. The liver to plasma ratios of rosuvastatin and bromfenac were reduced but the liver concentration of the drugs remained unchanged by RIF treatment. The liver concentrations of carotegrast, CP-I, and CP-III were unchanged at 1 h but increased at 6 h in the RIF-treated group. The passive permeability, active uptake, and biliary excretion were characterized in suspended and sandwich-cultured monkey hepatocytes and then incorporated into the monkey PBPK model. As demonstrated by the PBPK model, the plasma exposure is increased through OATP inhibition while liver exposure is maintained by passive permeability driven from an elevated plasma level. Liver exposure is sensitive to the changes of metabolism and biliary clearances. The model further suggested the involvement of additional mechanisms for hepatic uptakes of rosuvastatin and bromfenac, and of the inhibition of biliary excretion for carotegrast, CP-I, and CP-III by RIF. Collectively, impaired OATP function would not reduce the liver exposure of its substrates in monkeys.

A phase 1 dose-escalation and dose-expansion study to assess the safety and efficacy of CKD-516, a novel vascular disrupting agent, in combination with Irinotecan in patients with previously treated metastatic colorectal cancer.

Introduction The combination of an anti-angiogenic agent with cytotoxic chemotherapy is a standard treatment strategy for metastatic colorectal cancer. CKD-516 is an oral vascular disrupting agent that was preliminarily shown to be safe and efficacious as a monotherapy in refractory solid cancers. We evaluated the recommended phase 2 dose, safety, and preliminary efficacy of CKD-516 in combination with irinotecan in treatment-refractory metastatic colorectal cancer. Methods This phase 1 dose-escalation and dose-expansion study included patients with treatment-refractory metastatic colorectal cancer. CKD-516 tablets were administered for five consecutive days followed by two days off in combination with intravenous irinotecan (120 mg/m2) administered on day one of each treatment cycle every two weeks. A traditional 3 + 3 dose-escalation design was used. Results In total, 16 and 23 patients were enrolled in the dose-escalation and dose-expansion cohorts, respectively. The most common adverse events included diarrhea (79%), nausea (74%), vomiting (67%), and neutropenia (62%). No dose-limiting toxicity occurred, and the recommended phase 2 dose was determined at CKD-516/irinotecan doses of 11/120 mg/m2. No cases of cardiac ischemia, cardiac dysfunction, or thromboembolism were reported. Among the 34 patients with available tumor response assessments, one patient achieved partial response (3%) and 26 patients achieved stable disease (76%). The median progression-free survival and overall survival were 4.1 and 11.6 months, respectively. Conclusion This phase 1 study showed that the combination of oral CKD-516 and irinotecan is safe and tolerable in metastatic, treatment-refractory colorectal patients and showed favorable efficacy outcomes. Further studies to confirm these preliminary findings are warranted. Trial registration number NCT03076957 (Registered at March 10, 2017).

Novel simultaneous method for the determination of avobenzone and oxybenzone in human plasma by UHPLC-MS/MS with phospholipid removal pretreatment: An application to a sunscreen clinical trial.

Application of sunscreen is one of many ways to protect skin from the harmful effects of UV radiation. Sunscreen products are widely used and regulated as over-the-counter drug products in the United States. The U.S. Food and Drug Administration recommends an assessment of human systemic absorption of sunscreen active ingredients with a Maximal Usage Trial. The FDA conducted a clinical study to determine the systemic exposure of sunscreen active ingredients present in 4 commercially available sunscreen products of different formulation types under maximal usage conditions. To support this clinical study, a sensitive and specific LC-MS/MS method for the simultaneous determination of the two sunscreens avobenzone and oxybenzone in human plasma was developed. Phospholipid removal 96-well protein precipitation plates were used for sample clean-up and the extracted samples were chromatographed on an Ethylene-Bridged Hybrid (BEH) C18 column in isocratic flow using 10 mM ammonium formate in 0.1% formic acid and methanol (24:76, v/v) as a mobile phase. A triple quadrupole mass spectrometer in multiple reaction monitoring (MRM) mode was used to acquire data. The method was validated as per current FDA bioanalytical method validation guidance, in the ranges 0.20-12.00 ng/mL for avobenzone and 0.40-300.00 ng/mL for oxybenzone. The validated method was used toanalyzethese active ingredients in human clinical study samples.

Human metabolism and urinary excretion kinetics of the UV filter Uvinul A plus® after a single oral or dermal dosage.

Hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate, better known under its trading name Uvinul A plus® is a UV filter mainly used in sunscreens, but also present in other cosmetic products with a maximum concentration of 10% (w/w) according to the EU directive. In this study we investigated the human metabolism after a single oral and a single dermal dose of Uvinul A plus®, respectively. Samples collected within 72 h of administration were analyzed with a newly developed UHPLC-MS/MS method. Results of the study revealed three major urinary metabolites, namely 2-(4-amino-2-hydroxybenzoyl)benzoic acid (AHB), 2-(4-(ethylamino)-2-hydroxybenzoyl)benzoic acid (EHB) and 2-(4-(diethylamino)-2-hydroxybenzoyl)benzoic acid (DHB), representing 52% of the administered oral dose. The three major metabolites are further converted into four minor metabolites with an additional hydroxyl group in the aniline moiety. Toxicokinetic parameters (amount excreted, tmax, elimination constant and half-life t1/2) and conversion factors were determined for the three major metabolites. The conversion factors were used to estimate the mean daily exposure to Uvinul A plus® in spot urine samples from 58 volunteers not intentionally exposed to Uvinul A plus® derived from a pilot study. The three major metabolites were quantifiable in 26% of the samples. In 35% of the samples, at least one major metabolite could be quantified. The daily systemic exposure to Uvinul A plus® was estimated to approximately 8.1-9.3 µg/d by applying the combined conversion factor for all three major metabolites. In conclusion, a very low systemic exposure to DHHB was observed with regard to the no observed adverse effect level (NOAEL) as an established threshold for chronic uptake.

Phase I and pharmacokinetic study of the vascular-disrupting agent CKD-516 (NOV120401) in patients with refractory solid tumors.

We report a phase I pharmacological study of an oral formulation of CKD-516, a vascular-disrupting agent, in patients with refractory solid tumors. Twenty-seven patients (16 in the dose-escalation cohort and 11 in the expansion cohort) received a single daily dose (5-25 mg) of CKD-516 five days per week. Nausea (67%) and diarrhea (63%) were the most common treatment-related adverse events. The recommended phase II dose of oral CKD-516 was 20 mg/d (15 mg/d with a body surface area (BSA) <1.65 m2 ). Notably, S-516 half-lives in patients receiving 15-20 mg CKD-516/d significantly differed between patients with and without splenomegaly that is suggestive of portal hypertension associated with liver cirrhosis (6.1 vs 4.6 hours, respectively). Of 11 patients without splenomegaly who completed at least one cycle of a daily CKD-516 dose of either 15 or 20 mg, only one patient (9.1%) suffered from any dose-limiting toxicity. We conclude that a daily oral dose of 15 or 20 mg CKD-516 five days per week could be tolerable in patients without liver cirrhosis.

Phototoxic risk assessment of dermally-applied chemicals with structural variety based on photoreactivity and skin deposition.

Combined use of photochemical and pharmacokinetic (PK) data for phototoxic risk assessment was previously proposed, and the system provided reliable phototoxic risk predictions of chemicals in same chemical series. This study aimed to verify the feasibility of the screening system for phototoxic risk assessment on dermally-applied chemicals with wide structural diversity, as a first attempt. Photochemical properties of test chemicals, 2-acetonaphthalene, 4'-methylbenzylidene camphor, 6-methylcoumarin, methyl N-methylanthranilate, and sulisobenzone, were evaluated in terms of UV absorption and reactive oxygen species (ROS) generation, and PK profiles of the test chemicals in rat skin were characterized after dermal co-application. All test chemicals showed strong UVA/B absorption with molar extinction coefficients of over 3000 M-1⋅cm-1, and irradiated 2-acetonaphthalene, 6-methylcoumarin, and methyl N-methylanthranilate exhibited significant ROS generation. Dermally-applied 2-acetonaphthalene and 4'-methylbenzylidene camphor indicated high and long-lasting skin deposition compared with the other test chemicals. Based on the photochemical and PK data, 2-acetonaphthalene was predicted to have potent phototoxic risk. The predicted phototoxic risk of the test chemicals by integration of obtained data was mostly consistent with their in vivo phototoxicity observed in rat skin. The screening strategy employing photochemical and PK data would have high prediction capacity and wide applicability for photosafety evaluation of chemicals.

Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: A prior pilot study demonstrated the systemic absorption of 4 sunscreen active ingredients; additional studies are needed to determine the systemic absorption of additional active ingredients and how quickly systemic exposure exceeds 0.5 ng/mL as recommended by the US Food and Drug Administration (FDA). Objective: To assess the systemic absorption and pharmacokinetics of the 6 active ingredients (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate) in 4 sunscreen products under single- and maximal-use conditions. Design, Setting, and Participants: Randomized clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) was conducted in 48 healthy participants. The study was conducted between January and February 2019. Interventions: Participants were randomized to 1 of 4 sunscreen products, formulated as lotion (n = 12), aerosol spray (n = 12), nonaerosol spray (n = 12), and pump spray (n = 12). Sunscreen product was applied at 2 mg/cm2 to 75% of body surface area at 0 hours on day 1 and 4 times on day 2 through day 4 at 2-hour intervals, and 34 blood samples were collected over 21 days from each participant. Main Outcomes and Measures: The primary outcome was the maximum plasma concentration of avobenzone over days 1 through 21. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, homosalate, octisalate, and octinoxate over days 1 through 21. Results: Among 48 randomized participants (mean [SD] age, 38.7 [13.2] years; 24 women [50%]; 23 white [48%], 23 African American [48%], 1 Asian [2%], and 1 of unknown race/ethnicity [2%]), 44 (92%) completed the trial. Geometric mean maximum plasma concentrations of all 6 active ingredients were greater than 0.5 ng/mL, and this threshold was surpassed on day 1 after a single application for all active ingredients. For avobenzone, the overall maximum plasma concentrations were 7.1 ng/mL (coefficient of variation [CV], 73.9%) for lotion, 3.5 ng/mL (CV, 70.9%) for aerosol spray, 3.5 ng/mL (CV, 73.0%) for nonaerosol spray, and 3.3 ng/mL (CV, 47.8%) for pump spray. For oxybenzone, the concentrations were 258.1 ng/mL (CV, 53.0%) for lotion and 180.1 ng/mL (CV, 57.3%) for aerosol spray. For octocrylene, the concentrations were 7.8 ng/mL (CV, 87.1%) for lotion, 6.6 ng/mL (CV, 78.1%) for aerosol spray, and 6.6 ng/mL (CV, 103.9%) for nonaerosol spray. For homosalate, concentrations were 23.1 ng/mL (CV, 68.0%) for aerosol spray, 17.9 ng/mL (CV, 61.7%) for nonaerosol spray, and 13.9 ng/mL (CV, 70.2%) for pump spray. For octisalate, concentrations were 5.1 ng/mL (CV, 81.6%) for aerosol spray, 5.8 ng/mL (CV, 77.4%) for nonaerosol spray, and 4.6 ng/mL (CV, 97.6%) for pump spray. For octinoxate, concentrations were 7.9 ng/mL (CV, 86.5%) for nonaerosol spray and 5.2 ng/mL (CV, 68.2%) for pump spray. The most common adverse event was rash, which developed in 14 participants. Conclusions and Relevance: In this study conducted in a clinical pharmacology unit and examining sunscreen application among healthy participants, all 6 of the tested active ingredients administered in 4 different sunscreen formulations were systemically absorbed and had plasma concentrations that surpassed the FDA threshold for potentially waiving some of the additional safety studies for sunscreens. These findings do not indicate that individuals should refrain from the use of sunscreen. Trial Registration: ClinicalTrials.gov Identifier: NCT03582215.

VITREOUS PROSTAGLANDIN E2 CHANGES AFTER TOPICAL ADMINISTRATION OF DICLOFENAC 0.1%, INDOMETHACIN 0.5%, NEPAFENAC 0.3%, AND BROMFENAC 0.09.

PURPOSE: To evaluate the vitreous concentration of different nonsteroidal anti-inflammatory drugs (NSAIDs) after topical administration and the related prostaglandin E2 (PGE2) levels in patients undergoing pars plana vitrectomy. METHODS: A prospective, randomized, investigator-masked study was performed. One hundred four patients scheduled for a pars plana vitrectomy for an epiretinal membrane or a macular hole were randomized to receive topical diclofenac 0.1%, indomethacin 0.5%, nepafenac 0.3%, bromfenac 0.09%, or placebo 3 days before surgery. At the beginning of surgery, a sample of undiluted vitreous was collected in each patient to assess NSAIDs concentration and PGE2 levels. RESULTS: The median vitreous concentrations were 203.35 (interquartile range 146.54-264.18) pg/mL for diclofenac, 243.45 (interquartile range 156.96-365.37) pg/mL for nepafenac, 438.21 pg/mL (interquartile range, 282.52-645.87) for its active metabolite amfenac, 350.14 (interquartile range, 290.88-481.95) pg/mL for indomethacin, and 274.59 (245.43-358.25) pg/mL for bromfenac. Vitreous PGE2 levels were significantly lower for all the NSAIDs groups compared with the control group (P < 0.001). A statistically significant higher vitreous PGE2 level was found in the diclofenac group compared with the other NSAIDs groups (P < 0.05). CONCLUSION: Topical NSAIDs achieve sufficient vitreous concentration to decrease vitreous PGE2 levels compared with the control group. The different efficacy in reducing PGE2 concentration may affect the management of posterior segment inflammation.

Organic ultraviolet filters in nearshore waters and in the invasive lionfish (Pterois volitans) in Grenada, West Indies.

Sunscreens and other personal care products use organic ultraviolet (UV) filters such as oxybenzone, 4-methylbenzylidene camphor, Padimate-O, and octyl methoxycinnamate to prevent damage to human skin. While these compounds are effective at preventing sunburn, they have a demonstrated negative effect on cells and tissues across taxonomic levels. These compounds have a relatively short half-life in seawater but are continuously re-introduced via recreational activities and wastewater discharge, making them environmentally persistent. Because of this, testing seawater samples for the presence of these compounds may not be reflective of their abundance in the environment. Bioaccumulation of organic ultraviolet filters in a high-trophic level predator may provide greater insight to the presence and persistence of these compounds. To address this, the present study collected seawater samples as well as muscle and stomach content samples from the invasive Pacific lionfish (Pterois volitans) in the nearshore waters of Grenada, West Indies to examine the use of lionfish as potential bioindicator species. Seawater and lionfish samples were collected at four sites that are near point sources of wastewater discharge and that receive a high number of visitors each year. Samples were tested for the presence and concentrations of oxybenzone, 4-methylbenzylidene camphor (4-MBC), Padimate-O, and octyl methoxycinnamate (OMC) using liquid chromatography-mass spectrometry. Oxybenzone residues were detected in 60% of seawater samples and OMC residues were detected in 20% of seawater samples. Seawater samples collected in the surface waters near Grenada's main beach had oxybenzone concentrations more than ten times higher than seawater samples collected in less frequently visited areas and the highest prevalence of UV filters in lionfish. Residues of oxybenzone were detected in 35% of lionfish muscle and 4-MBC residues were detected in 12% of lionfish muscle. Padimate-O was not detected in either seawater or lionfish samples. No organic UV filters were detected in lionfish stomach contents. Histopathologic examination of lionfish demonstrated no significant findings attributed to UV filter toxicity. These findings report UV filter residue levels for the first time in inshore waters in Grenada. Results indicate that lionfish may be bioaccumulating residues and may be a useful sentinel model for monitoring organic ultraviolet filters in the Caribbean Sea.

Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: The US Food and Drug Administration (FDA) has provided guidance that sunscreen active ingredients with systemic absorption greater than 0.5 ng/mL or with safety concerns should undergo nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies. Objective: To determine whether the active ingredients (avobenzone, oxybenzone, octocrylene, and ecamsule) of 4 commercially available sunscreens are absorbed into systemic circulation. Design, Setting, and Participants: Randomized clinical trial conducted at a phase 1 clinical pharmacology unit in the United States and enrolling 24 healthy volunteers. Enrollment started in July 2018 and ended in August 2018. Interventions: Participants were randomized to 1 of 4 sunscreens: spray 1 (n = 6 participants), spray 2 (n = 6), a lotion (n = 6), and a cream (n = 6). Two milligrams of sunscreen per 1 cm2 was applied to 75% of body surface area 4 times per day for 4 days, and 30 blood samples were collected over 7 days from each participant. Main Outcomes and Measures: The primary outcome was the maximum plasma concentration of avobenzone. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, and ecamsule. Results: Among 24 participants randomized (mean age, 35.5 [SD, 1.5] years; 12 (50%] women; 14 [58%] black or African American; 14 [58%]), 23 (96%) completed the trial. For avobenzone, geometric mean maximum plasma concentrations were 4.0 ng/mL (coefficient of variation, 6.9%) for spray 1; 3.4 ng/mL (coefficient of variation, 77.3%) for spray 2; 4.3 ng/mL (coefficient of variation, 46.1%) for lotion; and 1.8 ng/mL (coefficient of variation, 32.1%). For oxybenzone, the corresponding values were 209.6 ng/mL (66.8%) for spray 1, 194.9 ng/mL (52.4%) for spray 2, and 169.3 ng/mL (44.5%) for lotion; for octocrylene, 2.9 ng/mL (102%) for spray 1, 7.8 ng/mL (113.3%) for spray 2, 5.7 ng/mL (66.3%) for lotion, and 5.7 ng/mL (47.1%) for cream; and for ecamsule, 1.5 ng/mL (166.1%) for cream. Systemic concentrations greater than 0.5 ng/mL were reached for all 4 products after 4 applications on day 1. The most common adverse event was rash, which developed in 1 participant with each sunscreen. Conclusions and Relevance: In this preliminary study involving healthy volunteers, application of 4 commercially available sunscreens under maximal use conditions resulted in plasma concentrations that exceeded the threshold established by the FDA for potentially waiving some nonclinical toxicology studies for sunscreens. The systemic absorption of sunscreen ingredients supports the need for further studies to determine the clinical significance of these findings. These results do not indicate that individuals should refrain from the use of sunscreen. Trial Registration: ClinicalTrials.gov Identifier: NCT03582215.

Verifying community-wide exposure to endocrine disruptors in personal care products - In quest for metabolic biomarkers of exposure via in vitro studies and wastewater-based epidemiology.

This study aimed to identify human specific metabolites of selected known or suspected endocrine disruptors (EDCs), mainly UV filters, used in personal care and consumer products whose metabolism has hardly been explored and to select suitable candidate biomarkers for human exposure studies using wastewater based epidemiology (WBE). The analysis of metabolic biomarkers of target chemicals is crucial in order to distinguish between internal and external exposure, since many sources contribute to chemicals being discharged into wastewater. This was achieved through the employment of a new analytical framework for verification of biomarkers of exposure to chemicals combining human biomonitoring and water fingerprinting. Eight EDCs with unknown metabolic pathways (benzophenone-1 (BP-1); benzophenone-2 (BP-2); 4,4'-dihydroxybenzophenone (4,4'-DHBP); 4-benzylphenol (4-BenzPh); homosalate (HO); octocrylene (OC); 3-benzylidene camphor (3-BC), and two EDCs with known metabolism (bisphenol A (BPA) and benzophenone-3 (BP-3)) were tested. The biotransformation observed consisted mainly of phase I processes such as hydrolysis and hydroxylation together with phase II conjugation reactions such as sulphation and glucuronidation. Only two chemicals (BP-1, BP-3) were identified in urine and three chemicals (BPA, BP-1, BP-3) in wastewater. Five newly discovered metabolites (HO-Met1, OC-Met1, 4-BenzPh-Met4, 4-BenzPh-Met5 and 4-BenzPh-Met6) and one previously known metabolite (BPA-Met3) were detected in tested urine/wastewater samples from five WWTPs serving large communities ranging between 17 and 100 thousand inhabitants. The presence of metabolic biotransformation products of OC, 4-BenzPh, BPA and HO in wastewater provides evidence for internal exposure of studied populations to these chemicals.

In vivo schistosomicidal activity of 7-epiclusianone and its quantification in the plasma of healthy and Schistosoma mansoni infected mice using UPLC-MS/MS.

BACKGROUND: The tetraprenylated benzophenone 7-epiclusianone (7-epi) is a substance isolated from the fruits of Garcinia brasiliensis and in vitro studies have demonstrated that 7-epi is effective against Schistosoma mansoni adult worms. HYPOTHESIS/PURPOSE: Here we report the in vivo evaluation of 7-epi and its pharmacokinetic in healthy and Schistosoma mansoni infected mice. STUDY DESIGN AND METHODS: In this work, we assayed the schistosomicidal activity of 7-epi at the dose of 100 mg/kg and 300 mg/kg body weight/day in S. mansoni experimentally infected mice. Besides, two groups of animals were treated and a detailed analysis of plasma samples was performed by liquid chromatography coupled to mass spectrometry (LC-MS/MS). RESULTS: The worm burden showed a reduction in the infected mice after treatment with 300 mg/kg for five days (p < .05). And we found an increase of AUC0-∞ (20846 vs. 32438 ng.h/ml) and a decrease of total apparent clearance (0.006 vs. 0.004 l/h/kg) of 7- epi in the infected group compared to the healthy group. Consequently, the half-life increased (1.73 vs. 6.11 h) and Cmax was reduced (5427.5 vs. 3321.0 ng/ml) in the infected group compared to the healthy group. In addition, histopathological investigations were performed analysing liver samples from healthy and infected mice. CONCLUSION: The results showed significant schistosomicidal in vivo activity at 300 mg/kg. In addition, livers from S. mansoni infected mice showed a greater number of egg granulomas and the changes in the pharmacokinetic parameters in this group could be associated with the pathology of the murine experimental schistosomiasis.

Elucidation of the Impact of P-glycoprotein and Breast Cancer Resistance Protein on the Brain Distribution of Catechol-O-Methyltransferase Inhibitors.

P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) are clinically important efflux transporters that act cooperatively at the blood-brain barrier, limiting the entry of several drugs into the central nervous system (CNS) and affecting their pharmacokinetics, therapeutic efficacy, and safety. In the present study, the interactions of catechol-O-methyltransferase (COMT) inhibitors (BIA 9-1059, BIA 9-1079, entacapone, nebicapone, opicapone, and tolcapone) with P-gp and BCRP were investigated to determine the contribution of these transporters in their access to the brain. In vitro cellular accumulation and bidirectional transport assays were conducted in Madin-Darby canine kidney (MDCK) II, MDCK-MDR1, and MDCK-BCRP cells. In vivo pharmacokinetic studies were carried out for tolcapone and BIA 9-1079 in rats, with and without elacridar, a well-known P-gp and BCRP modulator. The results suggest that BIA 9-1079, nebicapone, and tolcapone inhibit BCRP in a concentration-dependent manner. Moreover, with net flux ratios higher than 2 and decreased over 50% in the presence of verapamil or Ko143, BIA 9-1079 was identified as a P-gp substrate while BIA 9-1059, entacapone, opicapone, and nebicapone were revealed to be BCRP substrates. In vivo, brain exposure was limited for tolcapone and BIA 9-1079, although tolcapone crossed the blood-brain barrier at a greater rate and to a greater extent than BIA 9-1079. The extent of brain distribution of both compounds was significantly increased in the presence of elacridar, attesting to the involvement of efflux transporters. These findings provide relevant information and improve the understanding of the mechanisms that govern the access of these COMT inhibitors to the CNS.

Dermal Uptake of Benzophenone-3 from Clothing.

Benzophenone-3 (also known as BP-3 or oxybenzone) is added to sunscreens, plastics, and some coatings to filter UV radiation. The suspected endocrine disruptor BP-3 has been detected in the air and settled dust of homes and is expected to redistribute from its original sources to other indoor compartments, including clothing. Given its physical and chemical properties, we hypothesized that dermal uptake from clothing could contribute to the body burden of this compound. First, cotton shirts were exposed to air at an elevated concentration of BP-3 for 32 days; the final air concentration was 4.4 µg/m3. Next, three participants wore the exposed shirts for 3 h. After 3 h of exposure, participants wore their usual clothing during the collection of urine samples for the next 48 h. Urine was analyzed for BP-3, a metabolite (BP-1), and six other UV filters. The rate of urinary excretion of the sum of BP-1 and BP-3 increased for all participants during and following the 3 h of exposure. The summed mass of BP-1 and BP-3 excreted during the first 24 h attributable to wearing exposed t-shirts were 12, 9.9, and 82 µg for participants 1, 2, and 3, respectively. Analysis of these results, coupled with predictions of steady-state models, suggest that dermal uptake of BP-3 from clothing could meaningfully contribute to overall body burden.

Fate of the sunscreen compound oxybenzone in Cyperus alternifolius based hydroponic culture: Uptake, biotransformation and phytotoxicity.

Oxybenzone (OBZ), a common ingredient in sunscreens and personal care products, has been frequently detected in effluents from municipal wastewater treatment plants and also in surface waters. OBZ is an emerging contaminant due to its adverse impacts on marine/aquatic ecosystems. To investigate the removal and degradation capacity of phytotreatment for OBZ, the common wetland plant species Cyperus alternifolius L. was exposed to this compound at 5, 25 and 50 µM for 120 h, respectively. Continuous uptake by roots and accumulation in plant tissues was observed over the exposure time, and depletion of spiked OBZ from the aqueous medium exceeded 73.9 ± 9.1% after 120 h. Similar to its fate in mammalian cells, OBZ is activated in a phase I reaction resulting in the hydroxylated metabolite 2,4-dihydroxybenzophenone (DHB). Independently, two phase II metabolites were identified as oxybenzone-glucoside (OBZ-Glu) and oxybenzone-(6-O-malonyl)-glucoside (OBZ-Mal-Glu) by LC-MS/MS. Formation of these metabolites increased over the experimental period. To our knowledge this is the first time that DHB, OBZ-Glu and OBZ-Mal-Glu are shown to be formed in higher plant tissues. Furthermore, plant defense systems-antioxidative enzymes (SOD, CAT, APOX and POX) were found to be elevated to counteract stress caused by exposure to OBZ. This study presents the huge potential of aquatic plants to cope with benzophenone type UV filters in contaminated water bodies.

Comparison of the In Vivo Biotransformation of Two Emerging Estrogenic Contaminants, BP2 and BPS, in Zebrafish Embryos and Adults.

Zebrafish embryo assays are increasingly used in the toxicological assessment of endocrine disruptors. Among other advantages, these models are 3R-compliant and are fit for screening purposes. Biotransformation processes are well-recognized as a critical factor influencing toxic response, but major gaps of knowledge exist regarding the characterization of functional metabolic capacities expressed in zebrafish. Comparative metabolic studies between embryos and adults are even scarcer. Using ³H-labeled chemicals, we examined the fate of two estrogenic emerging contaminants, benzophenone-2 (BP2) and bisphenol S (BPS), in 4-day embryos and adult zebrafish. BPS and BP2 were exclusively metabolized through phase II pathways, with no major qualitative difference between larvae and adults except the occurrence of a BP2-di-glucuronide in adults. Quantitatively, the biotransformation of both molecules was more extensive in adults. For BPS, glucuronidation was the predominant pathway in adults and larvae. For BP2, glucuronidation was the major pathway in larvae, but sulfation predominated in adults, with ca. 40% conversion of parent BP2 and an extensive release of several conjugates into water. Further larvae/adults quantitative differences were demonstrated for both molecules, with higher residue concentrations measured in larvae. The study contributes novel data regarding the metabolism of BPS and BP2 in a fish model and shows that phase II conjugation pathways are already functional in 4-dpf-old zebrafish. Comparative analysis of BP2 and BPS metabolic profiles in zebrafish larvae and adults further supports the use of zebrafish embryo as a relevant model in which toxicity and estrogenic activity can be assessed, while taking into account the absorption and fate of tested substances.

Bromfenac ophthalmic solution 0.09 %: human aqueous humor concentration detected by high-performance liquid chromatography.

The purpose of this study was to evaluate the aqueous humor concentrations of bromfenac ophthalmic solution 0.09 % in patients undergoing phacoemulsification. Patients requiring cataract extraction received one drop (50 µL) of bromfenac 0.09 % solution in the eye to be operated, before bedtime the day before surgery or the morning of the surgery. The last administration was recorded. At the time of paracentesis, an aqueous humor sample was collected with a 30-gauge needle attached to a TB syringe and was later analyzed by high-performance liquid chromatography for drug concentration. 188 treated volunteers and 48 control, untreated, subjects were included in the study. The mean aqueous concentration of bromfenac in the treated group was 37.60 ± 68.86 and 0 nM (nmol/L) in the control group (p < 0.0001). Correlation coefficient in bromfenac group between time elapsed from instillation and drug concentration was -0.16 (p not significant). Bromfenac showed properties of good penetration and stable concentration in aqueous humor up to about 12 h after instillation.

Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models.

Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro - in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds.