Evaluation of electric arc furnace‐processed steel slag for dermal corrosion,irritation, and sensitization from dermal contact

Electric arc furnace (EAF) steel slag is alkaline (pH of ~11–12) and contains metals, most notably chromium and nickel, and thus has potential to cause dermal irritation and sensitization at sufficient dose. Dermal contact with EAF slag occurs in many occupational and environmental settings because it is used widely in construction and other industrial sectors for various applications including asphaltic paving, road bases, construction fill, and as feed for cement kilns construction. However, no published study has characterized the potential for dermal effects associated with EAF slag. To assess dermal irritation, corrosion and sensitizing potential of EAF slag, in vitro and in vivo dermal toxicity assays were conducted based on the Organisation for Economic Co‐operation and Development (OECD) guidelines. In vitro dermal corrosion and irritation testing (OECD 431 and 439) of EAF slag was conducted using the reconstructed human epidermal (RHE) tissue model. In vivo dermal toxicity and delayed contact sensitization testing (OECD 404 and 406) were conducted in rabbits and guinea pigs, respectively. EAF slag was not corrosive and not irritating in any tests. The results of the delayed contact dermal sensitization test indicate that EAF slag is not a dermal sensitizer. These findings are supported by the observation that metals in EAF slag occur as oxides of low solubility with leachates that are well below toxicity characteristic leaching procedure (TCLP) limits. Based on these results and in accordance to the OECD guidelines, EAF slag is not considered a dermal sensitizer, corrosive or irritant. Copyright © 2014 John Wiley & Sons, Ltd.     

Assessment of the in vitro dermal irritation potential of cerium,silver, and titanium nanoparticles in a human skin equivalent model

Metal nanoparticles can potentially contact human skin during their manufacture and use in commercial products. This study examined the potential of metal nanoparticles to elicit irritant contact dermatitis in a human skin equivalent model (HSEM) derived from keratinocytes. Ag (10–100?nm), TiO₂ (22–214?nm), and CeO₂ (15–40?nm) nanoparticles were studied. The Ag particles were either coated/shelled with silica or capped with citrate or polyvinylpyrrolidone and were in water. The TiO₂ and CeO₂ particles were suspended in media containing 10% fetal bovine serum. The particles (1?mg/ml) were applied to the epidermal surface of the HSEM. Positive (5% sodium dodecyl sulfate (SDS)) and negative controls (saline or media) were included. After 1-h exposure at 37?°C, the HSEM was washed with saline to remove the nanoparticles. Following a 42-h incubation (37?°C), HSEM viability was assessed using the MTT assay. A test substance is considered a dermal irritant if the HSEM viability is?2, and CeO₂ nanoparticles examined were not dermal irritants under the conditions used in this study. The stratum corneum of the HSEM may limit penetration of metal nanoparticles to induce toxicity.     

Ocular delivery of cyclosporine A based on glyceryl monooleate/poloxamer 407 liquid crystalline nanoparticles: preparation,characterization, in vitro corneal penetration and ocular irritation

The purpose of this study was to develop an ophthalmic drug delivery system for cyclosporine A (CsA) based on glyceryl monooleate (GMO)/poloxamer 407 liquid crystalline nanoparticles with reduced ocular irritancy and improved corneal penetration. CsA-loaded liquid crystalline nanoparticles were prepared via fragmentation of a bulk GMO/poloxamer 407 cubic phase gel by high-pressure homogenization and characterized. Corneal permeation and retention was evaluated using modified Franz diffusing cells. Intra-corneal transportation was investigated with fluorescein isothiocyanate (FITC)-labeled liquid crystalline nanoparticles. Ocular irritation was then evaluated using the Draize method. The mean particle size of liquid crystalline nanoparticles was 193.5?nm and the entrapment efficiency was 95.11?±?0.67%. A bicontinuous cubic phase of cubic P-type was determined using cryo-transmission electron microscopy (cryo-TEM) observation and small angle X-ray diffraction (SAXD) analysis. A 1.52-fold increase in J_s and a 2.2-fold increase in corneal retention was achieved by liquid crystalline nanoparticles compared with oil solution. In vitro corneal permeation investigated with FITC-labeled liquid crystalline nanoparticles revealed that CsA penetrated across the cornea under the transportation of liquid crystalline nanoparticles. Liquid crystalline nanoparticles exhibited excellent ocular tolerance in the ocular irritation test. This low-irritant vehicle based on liquid crystalline nanoparticles might be a promising system for effective ocular CsA delivery.     

Mechanisms of ocular toxicity using the in vitro bovine lens and sodium dodecyl sulfate as a chemical model.

Previous work using the in vitro bovine lens as a model has shown a correlation between toxicity and lens optical function and showed much higher sensitivity in detecting irritancy of several surfactants at much lower concentrations than the Draize score. In the current study, cultured bovine lenses were used to study the effects of the surfactant sodium dodecyl sulfate (SDS) on lens optical properties and mitochondrial integrity. Bovine lenses were exposed to SDS (0.1 to 0.00625%) for 30 min and cultured for 24 h. Compared to controls (n = 17), loss of sharp focus was evident immediately following exposure to 0.1% SDS (n = 14, p < 0.0001). At 24 h loss of sharp focus became evident in all groups. Loss of lens transparency, significant increase in lens wet weight, and axial length were seen 24 h postexposure in lenses treated with 0.1 to 0.025% SDS. Confocal analysis 24 h postexposure showed SDS concentration-dependent decrease in number and length of the mitochondria in lens epithelial and superficial cortical fiber cells. The results of this study show a correlation between lens optical properties and metabolic function and together provide a sensitive in vitro model of ocular chemical toxicity. Results of confocal analysis suggest that the mitochondrial integrity of the superficial cortical fiber cells is most sensitive to damage caused by SDS. The results further suggest that recovery of lens metabolic function is necessary for the recovery of lens optical properties.     

In vitro dermal absorption rate testing of certain chemicals of interest to the Occupational Safety and Health Administration: summary and evaluation of USEPA's mandated testing

In 2004, the United States Environmental Protection Agency (USEPA) published a final test rule in the US Federal Register requiring in vitro dermal penetration rate testing for selected industrial chemicals. The test rule described procedures for determining a permeability coefficient (Kp) and two short-term dermal absorption rates at 10 and 60min using human cadaver skin mounted in an in vitro diffusion cell model. According to the USEPA announcement, the selected chemicals were to be spiked with their radiolabeled form and tested in either water, isopropyl myristate (IPM) or neat depending on their physical character at room temperature, their aqueous solubility, their potential to damage the skin and their ability to achieve the study endpoints as prescribed. Overall, and for the majority of chemicals, the short-term absorption rates were higher at 10min than at 60min and the portion of applied dose remaining in the skin at the end of the exposure period was greater than the portion of dose that had penetrated through the skin and was detected in the receptor solution. In contrast to this, the amount of chemical in the receptor solution at study termination for the Kp (steady-state) experiments was greater than the amount remaining in the skin. For the Kp experiments, which lasted from 2 to 48h, a majority of skins exposed to neat chemical exhibited a reduced barrier function. However, integrity was mostly unaltered for skins from the short-term experiments and Kp experiments using chemicals applied either in water or IPM. Quantitative structure activity relationship (QSAR) model-predicted Kp values were in fair agreement with experimental data for those chemicals that were applied in a water vehicle when the integrity of the skin was not compromised. However, QSAR-derived Kp values were not predictive for those chemicals when applied in IPM vehicle or neat. Absorption predictions, based on the measured Kp and steady-state flux data for chemicals applied in water or neat, respectively, were comparable to measured values at both 10 and 60min. Kp data for chemicals applied in water and the flux values for neat chemicals will be useful for making estimates of skin absorption in occupational settings. Kp measurements for chemicals applied in IPM vehicle are not envisioned to provide useful data for estimating the risk from dermal exposure to chemicals in the workplace. When available, in vitro dermal flux measurements should be combined with toxicity information in order to improve the utility of chemical skin notations.     

Development of a drug-in-adhesive patch combining ion pair and chemical enhancer strategy for transdermal delivery of zaltoprofen: pharmacokinetic,pharmacodynamic and in vitro/in vivo correlation evaluation

The aim of the study was to develop a drug-in-adhesive patch system for transdermal delivery of zaltoprofen (ZAL). The formulation was designed in combination with the ion pair and chemical enhancer strategy. Seven organic amines were chosen as counter ions, and the prepared ion pairs were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The in vivo pharmacokinetic performance of ZAL was studied on rabbits following transdermal and intravenous administration. A deconvolution method was applied to determine the correlation between the in vitro permeation and the in vivo absorption. Acetic acid-induced writhing response was conducted on mice to evaluate the analgesic effect. In vitro permeation results showed that both ion pairs and chemical enhancers were effective in modulating ZAL skin permeation from patches. The enhancement ratio was negatively correlated to the polar surface area (PSA) of counter ions, and was positively correlated to the octanol–water partition coefficient (log K_o/w) of chemical enhancers, respectively. The optimized formulation contained 10% (w/w) ZAL-triethylamine and 10% (w/w) isopropyl myristate, with DURO-TAK® 87-4098 as the pressure sensitive adhesive matrix. Furthermore, the in vitro permeation data were well correlated with the in vivo absorption data. The analgesic effect of the optimized patch was comparable to the commercial indometacin plasters. In conclusion, it was feasible for transdermal delivery of ZAL by the synergistic action of ion pair and chemical enhancer, and the in vitro permeation data were indicative of the in vivo performance for the developed patches.     

An alkylpolyglucoside surfactant as a prospective pharmaceutical excipient for topical formulations: The influence of oil polarity on the colloidal structure and hydrocortisone in vitro/in vivo permeation

There is a growing need for research into new skin- and environment-friendly surfactants. This paper focuses on a natural surfactant of an alkylpolyglucoside type, which can form both thermotropic and lyotropic liquid-crystalline phases. The aim of this study was to relate some physicochemical properties (characterised by polarisation and transmission electron microscopy, thermal analysis and rheology) of the three formulations based on cetearyl glucoside and cetearyl alcohol, to the results of in vitro and in vivo bioavailability of hydrocortisone (HC). The three formulations contained oils of different polarity (medium chain triglycerides: MG, isopropyl myristate: IPM and light liquid paraffin: LP), respectively. In vitro permeation was followed through the artificial skin constructs (ASC), while the parameters measured in vivo were erythema index: EI (using instrumental human skin blanching assay), transepidermal water loss (TEWL) and stratum corneum hydration (SCH). The vehicles based on cetearyl glucoside and cetearyl alcohol showed a complex colloidal structure of lamellar liquid-crystalline and lamellar gel-crystalline type, depending on oil polarity. Rheological profile of the vehicle was directly related to the in vitro profile of the HC permeation. In vivo results suggested that the vehicle with MG retarded the HC permeation, whereas less polar IPM and non-polar LP enhanced it. It is suggested that the enhancement is achieved either by a direct interaction with lipid lamellae of the SC or indirectly by improving skin hydration.

There were no adverse effects during in vivo study, which indicates a good safety profile of this alkylpolyglucoside surfactant.     

Determination of microsome and hepatocyte scaling factors for in vitro/in vivo extrapolation in the rat and dog

1.?In vivo clearance predictions from in vitro assays require scaling factors to relate the concentrations of hepatocytes or microsomal protein to the intact liver.

2.?The aims were to measure the variability in scaling factors for Wistar rat and beagle dog for which the literature is particularly scarce and determine any sex differences.

3.?Scaling factors were determined by comparing the cytochrome P450 (P450) content in hepatocytes or microsomes against the P450 content of fresh liver homogenate. The use of fresh homogenate is recommended as freezing can increase contamination and affect the P450 assay.

4.?Mean_geo hepatic microsomal concentrations in Wistar rats were 61 mg g^?1 liver (95% confidence interval (CI); 47–75 mg g^?1 liver) and in beagle dogs 55 mg g^?1 liver (95% CI = 48–62 mg g^?1 liver). Mean_geo hepatocellularity was 163 × 10⁶ cells g^?1 liver for Wistar rats (95% CI = 127–199 × 10⁶ cells g^?1 liver) and 169 × 10⁶ cells g^?1 liver (95% CI = 131–207 × 10⁶ cells g^?1 liver) for beagle dogs. The data generated in this study indicate a consistency in scaling factors between rat and dog. No sex differences were observed.     

定量检测体外诊断试剂的线性评价方法介绍及其在肿瘤标志物试剂盒检验中的应用

目的建立和评价定量体外诊断试剂注册检验中评价数据线性的方法。方法参考CLSI指南EP6-A并结合注册检验工作中的实际情况和相关规定,提出了线性评价的建议方法,并应用该方法从试剂盒校准品和样品两个方面对某企业糖类抗原19-9（CA19-9）定量检测试剂盒进行了线性评价。结果试剂盒校准品回归方程相关系数r的绝对值为0.9989,符合相应要求。线性评价用样品检测结果的最优回归方程为直线方程,测定值在10~500U·mL-1范围内呈现线性,符合企业声明的线性范围。结论被评价试剂盒线性符合相应要求;本文提出的建议方法在肿瘤标志物定量检测试剂盒注册检验线性评价中显示出较好的适用性,可供从事该类工作的检验人员参考。     

基于体外消化/MDCK细胞模型测定地龙中镉和砷的生物可给性及风险评估

为了考察动物药地龙中镉(Cd)和砷(As)的生物可给性,并对Cd和As的风险进行评估,本研究采用电感耦合等离子体质谱(ICP-MS)法测定了地龙中Cd和As的残留量;建立in vitro PBET (physiologically based extraction test)体外模拟消化/MDCK细胞模型考察地龙中Cd和As的生物可给性;分别采用危害指数法(HI)和暴露限值法(MOE)对于地龙中Cd和As的残留总量以及生物可给量的风险进行评估。结果表明:6批地龙中Cd和As的残留总量范围分别为8.319～33.606 mg·kg^-1和0.532～16.412 mg·kg^-1。经过MDCK细胞转运后,地龙中Cd的生物可给性在10.13%～64.16%之间; As的生物可给性在2.72%～46.57%之间。风险评估的结果表明:MDCK细胞转运前,所有批次地龙中As的MOE值以及Cd的HI值均大于1, As的风险可接受, Cd的风险不可接受; MDCK细胞转运后,除了1批地龙外,其余5批地龙中Cd的HI值均小于1 (风险降低至安全范围内)。本研究为...     

Establishment and assessment of a novel in vitro bio-PK/PD system in predicting the in vivo pharmacokinetics and pharmacodynamics of cyclophosphamide

1.?A novel bio-pharmacokinetic/pharmacodynamic (PK/PD) system was established and assessed in predicting the PK parameters and PD effects of the model drug cyclophosphamide (CP) considering the interrelationships between drug metabolism, pharmacological effects and dynamic blood circulation processes in vitro.

2.?The system contains a peristaltic pump, a reaction chamber with rat liver microsomes (RLMs) encapsulated in pluronic F127–acrylamide–bisacrylamide (FAB) hydrogels, an effector cell chamber and a recirculating pipeline. The metabolism and pharmacological effects of CP (5, 10 and 20?mM) were measured by HPLC and MTT assay. A mathematical model based on mass balance was used to predict the in vitro clearance of CP. In vivo clearance of CP was estimated by in vitro to in vivo extrapolations (IVIVE) and simulations using Simcyp® software.

3.?The predicted in vivo clearance of CP at concentrations of 5, 10 and 20?mM was 11.36, 10.12 and 10.68?mL/min/kg, respectively, within two-fold differences compared with the reported 11.1?mL/min/kg. The survival ratio of effector cells during the metabolism and circulation of CP was significantly enhanced.

4.?This system may serve as an alternative approach to predict in vivo metabolism, pharmacological effects and toxicity of drugs, ensuring an efficient drug screening process.     

Classification and labeling of industrial products with extreme pH by making use of in vitro methods for the assessment of skin and eye irritation and corrosion in a weight of evidence approach

Classification and labeling of products with extreme pH values (?2 or ?11.5) is addressed in chemicals legislation. Following determination of pH and alkaline/acid reserve, additional in vitro tests are needed, especially to substantiate results less than corrosive. However, only limited experience with the practical application of in vitro methods to determine appropriate classifications for pH extreme products is available so far. Expert judgment and weight of evidence are given major roles under the globally harmonized system of classification and labeling of chemicals (GHS) and should be performed on a sound data basis. We have used a tiered testing strategy to assess 20 industrial products (cleaning and metal pretreatment) regarding their corrosive and irritating properties towards human skin models in vitro in the EpiDerm™ skin corrosion and/or skin irritation test. Nine dilutions of individual compounds were additionally tested. Non-corrosive samples were tested in the Hen’s egg test chorioallantoic membrane (HET-CAM). We demonstrate how data is combined in a weight of evidence expert judgment, and give examples of classification decisions. To our knowledge this is the first comprehensive analysis of industrial products with extreme pH values to determine irritating and corrosive properties by making use of in vitro methods in a weight of evidence approach.     

Regulatory accepted but out of domain: In vitro skin irritation tests for agrochemical formulations

Several in vitro methods have gained regulatory acceptance for the prediction of skin irritation and corrosion. However, the test guidelines for the majority of in vitro methods do not state whether they are applicable to agrochemical formulations. Hence, we would like to share the results from our routine skin corrosion and irritation testing of agrochemical formulations in which both in vitro (according to OECD TG 431 and OECD TG 439) and in vivo (according to OECD TG 404) tests were conducted as regulatory requirements. The in vitro skin irritation test did not correlate well with the CLP classification by in vivo results (44% sensitivity, 60% specificity, and 54% accuracy, based on 65 data pairs). This indicates a lack of applicability of the current protocol of the in vitro skin irritation test for agrochemical formulations. The data set did not contain formulations which were skin corrosive in vivo and hence its applicability could not be assessed. The correlation of in vitro skin corrosion testing to formulations which were not corrosive in vivo was, however, high (95% specificity based on 81 data pairs).     

Examining the feasibility of mixture risk assessment: A case study using a tiered approach with data of 67 pesticides from the Joint FAO/WHO Meeting on Pesticide Residues (JMPR)

The way in which mixture risk assessment (MRA) should be included in chemical risk assessment is a current topic of debate. We used data from 67 recent pesticide evaluations to build a case study using Hazard Index calculations to form risk estimates in a tiered MRA approach in line with a Framework proposed by WHO/IPCS. The case study is used to illustrate the approach and to add detail to the existing Framework, and includes many more chemicals than previous case studies.A low-tier MRA identified risk as being greater than acceptable, but refining risk estimates in higher tiers was not possible due to data requirements not being readily met. Our analysis identifies data requirements, which typically expand dramatically in higher tiers, as being the likely cause for an MRA to fail in many realistic cases. This forms a major obstacle to routine implementation of MRA and shows the need for systematic generation and collection of toxicological data. In low tiers, hazard quotient inspection identifies chemicals that contribute most to the HI value and thus require attention if further refinement is needed. Implementing MRA requires consensus on issues such as scope setting, criteria for performing refinement, and decision criteria for actions.     

Timely awareness and prevention of emerging chemical and biochemical risks in foods: Proposal for a strategy based on experience with recent cases

A number of recent food safety incidents have involved chemical substances, while various activities aim at the early identification of emerging chemical risks. This review considers recent cases of chemical and biochemical risks, as a basis for recommendations for awareness and prevention of similar risks at an early stage. These cases include examples of unapproved genetically modified food crops, intoxications with botanical products containing unintentionally admixed toxic herbs, residues of unapproved antibiotics and contaminants in farmed aquaculture species such as shrimp and salmon; and adverse effects of chemical and biological pesticides of natural origin. Besides case-specific recommendations for mitigation of future incidents of the same nature, general inferences and recommendations are made. It is recommended, for example, to establish databases for contaminants potentially present within products. Pro-active reconnaissance can facilitate the identification of products potentially contaminated with hazardous substances. In international trade, prevention and early identification of hazards are aided by management systems for product quality and safety, rigorous legislation, and inspections of consignments destined for export. Cooperation with the private sector and foreign authorities may be required to achieve these goals. While food and feed safety are viewed from the European perspective, the outcomes also apply to other regions.     

Case studies putting the decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping) into practice

Case studies covering carbonaceous nanomaterials, metal oxide and metal sulphate nanomaterials, amorphous silica and organic pigments were performed to assess the Decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping). The usefulness of the DF4nanoGrouping for nanomaterial hazard assessment was confirmed. In two tiers that rely exclusively on non-animal test methods followed by a third tier, if necessary, in which data from rat short-term inhalation studies are evaluated, nanomaterials are assigned to one of four main groups (MGs). The DF4nanoGrouping proved efficient in sorting out nanomaterials that could undergo hazard assessment without further testing. These are soluble nanomaterials (MG1) whose further hazard assessment should rely on read-across to the dissolved materials, high aspect-ratio nanomaterials (MG2) which could be assessed according to their potential fibre toxicity and passive nanomaterials (MG3) that only elicit effects under pulmonary overload conditions. Thereby, the DF4nanoGrouping allows identifying active nanomaterials (MG4) that merit in-depth investigations, and it provides a solid rationale for their sub-grouping to specify the further information needs. Finally, the evaluated case study materials may be used as source nanomaterials in future read-across applications. Overall, the DF4nanoGrouping is a hazard assessment strategy that strictly uses animals as a last resort.