Posters & Presentations
Shipping Study to Evaluate the Performance of the LabCyte EPI-MODEL 24 Tissues for Use in the Skin Irritation Test (OECD TG 439) After Long-Haul Airfreight
March 18, 2019It is recommended that an evaluation of the impact of shipping of Reconstructed human Epidermis (RhE) tissues be conducted especially after long-haul airfreight shipments. The OECD Test Guideline 439 (OECD TG 439), In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method, recommends that users do so by verifying the barrier properties of the tissues after receipt. In this study, LabCyte EPI-MODEL 24 tissues were received in the USA after an overnight shipment from Japan and were tested to evaluate their performance after shipment using several endpoints. First, the viability of untreated tissues incubated overnight in culture medium was assessed using the vital dye MTT and expressed as Optical Density (OD570-650) values. The calculated OD values were 1.2 (J-TEC) and 0.99 (IIVS) and within the range established by the manufacturer (0.8 - 2.5). The barrier function was further evaluated after the tissues were exposed to the assay negative control (Phosphate Buffered Saline - PBS) and to four concentrations of the positive control, Sodium Lauryl Sulfate (SLS) (1.0, 2.0, 3.0 and 4.0 mg/mL). The calculated IC50 values were 2.7 mg/mL (J-TEC) and 3.4 mg/mL (IIVS), respectively, and within the established historical range (1.4 - 4.0 mg/mL). The analysis of the results generated by the two labs (J-TEC and IIVS) demonstrated that the tissue lot met the acceptance criteria developed by the tissue manufacturer under conditions of shipping stress. Finally, the histological analysis of untreated fixed tissues identified all tissue layers and supported the conclusion that the tissue model was acceptable for use in subsequent studies after long-haul airfreight shipment. Such shipping studies are critical to gaining confidence in the tissues’ performance when used for research, industrial, and regulatory testing purposes.
Regarding the References for Reference Chemicals of Alternative Methods
March 18, 2019The selection of reference and proficiency chemicals is an important component of method validation and proficiency evaluations. Reference chemicals are a set of test substances used by a method developer to evaluate there liability and relevance of a new method, in comparison to reference data (usually to a validated reference method). Proficiency chemicals, as defined in OECD Guidance Document on Good In Vitro Method Practices, are defined post validation as a subset of the reference chemicals, or other chemicals with sufficient supporting data, that are used by naive laboratories to demonstrate technical competence with a validated test method. Proficiency chemicals should cover different physical states, several chemical classes within the applicability domain of the method and yield the full range of response (in the validated reference method and in vivo). They shall be commercially available (at non prohibitive costs) and have high quality reference data. If reference and subsequent proficiency chemicals are chosen without sufficient evidence for their inclusion, both test method evaluation and demonstration of technical proficiency can be hampered. In this report we present cases in which the selection of reference chemicals led to problems in the reproduction of the reference results and demonstration of technical proficiency.
Next Generation Tobacco Products and Skin Staining
March 18, 2019Next generation tobacco and nicotine products (NGPs) such as electronic cigarettes (EC) and tobacco heating products (THP) have reduced toxicity and hold great potential for reducing the risks associated with cigarette smoking. NGPs may also have hygiene benefits for consumers that switch to these products. In this study, the level of skin staining was assessed following exposure to a scientific reference cigarette (3R4F) and NGPs across the risk continuum; a prototype EC or a commercial THP (glo™). Test articles (TAs) were prepared by capturing cigarette smoke or EC/THP aerosol on Cambridge filter pads followed by elution with Dimethyl Sulfoxide (DMSO). Abattoir-obtained porcine skin (ø 0.5) samples were incubated at 37°C with each TA or DMSO control for 0, 0.25, 0.5, 1, 4 and 6h. Colour readings (L*, a*, b*) were measured for individual skin samples using a Konica Minolta CM-700d Spectrophotometer and mean colour change (ΔE) for each TA compared. The reference cigarette 3R4F TA showed the greatest colour change, which was significantly higher than the EC and THP TAs, both of which showed relatively little colour change. The mean ΔE values at 6 hrs were: 21.78 ± 2.80, 8.38 ± 2.93, 10.01 ± 2.53 and 9.23 ± 2.87 for 3R4F, a prototype EC, glo™ or DMSO respectively. The cigarette smoke extract significantly increased the level of staining of the skin samples whereas EC or the THP TAs induced little or no staining with values comparable to the DMSO control. For the first time, diverse NGPs across the risk continuum have been assessed in vitro for their impact on skin staining. Further studies are required to assess the long-term impact on skin staining of NGP aerosols.
Non-animal Vaginal Irritation Method Admitted into the US FDA Medical Devices Development Tool (MDDT)
October 18, 2018FDA’s recently launched Predictive Toxicology Roadmap calls for the optimization of non-animal methods for the safety evaluation of drugs, consumer products and medical devices. We have created an Industry Consortium comprised of manufacturers of personal lubricants/vaginal moisturizers and companies interested in the advancement of animal alternatives working collaboratively with stakeholders and the US FDA to develop an in vitro testing approach that could be used in place of the rabbit vaginal irritation (RVI) in pre-market submissions.
How the Good In Vitro Method Practices Guidance Document Can Help Implement New Toxicological Approaches: A Case Study in China
October 17, 2018Currently China is striving to adopt and implement non-animal, including in vitro, testing approaches for the safety assessment of cosmetics and ingredients. Collaborative efforts between industry and the Institute for In Vitro Sciences (IIVS, Gaithersburg, USA) have focused on the transfer of several OECD Test Guideline methods to government laboratories in China and have supported the creation of an in vitro toxicology testing laboratory within the Zhejiang Institute for Food and Drug Control (Hangzhou, China). Recently BASF SE (Ludwigshafen, Germany) and IIVS have partnered to introduce a cell based in vitro skin sensitization test, LuSens, into China using the principles of GIVIMP as a standard. This case study exemplifies the practical way in which the GIVIMP guidance can assist interested parties in the development, transfer and establishment of in vitro approaches.
Evaluation of Phototoxicity of Ocular Medical and Combination Devices
March 28, 2018To address ocular device induced phototoxicity, an in vitro 3T3 Neutral Red Uptake Phototoxicity test (OECD 432) for chemicals has been modified. Soft contact lenses formulated with three different photo-absorbing compounds and chemical solutions of these compounds were evaluated.
The Assessment of Phototoxicity Using the 3T3 Neutral Red Uptake (NRU) Phototoxicity Assay and a Modified Photo-Direct Peptide Reactivity Assay (DPRA)
March 28, 2018Alternative methods, including the validated 3T3 Neutral Red Uptake (NRU) Phototoxicity assay (OECD TG 432) may be used as a pre-clinical test to address phototoxicity. Currently, there are no validated alternative test methods to identify photoallergens; however, there are several validated alternative test methods to address skin sensitization, including the Direct Peptide Reactivity Assay (DPRA) (OECD 442C). To address photoallergy, we utilized the 3T3 Phototoxicity assay in combination with a modified photo-DPRA assay to determine if these assays were able to 1) identify compounds with phototoxicity potential and 2) discriminate between photoirritants and photoallergens.
Human In Vitro Models for Respiratory Toxicology: Evaluation of Goblet Cell Hyperplasia, Mucus Production, and Ciliary Beating Assays
March 28, 2018Robust non-animal models and assays for pulmonary toxicology are required to make competent product development and risk assessments for new materials requiring toxicity testing. Three in vitro assays (goblet cell hyperplasia , ciliary beat frequency , and MUC5AC quantitation) were evaluated for performance and reproducibility. To assess these assays, 6 laboratories contributed data using a common protocol utilizing IL-13 as an inducer of adverse mucociliary-relevant tissue changes. MatTek EpiAirway™ and Epithelix MucilAir™ 3D tissue models were used to evaluate endpoints using histology for GCH, software-based applications, Cilia FA and SAVA, for CBF, and ELISA assay for MUC5AC.
Use of Ex Vivo Precision-Cut Lung Slices as a Screening Tool for Potential Respiratory Toxicity of E-Liquids
March 28, 2018E-vapor product liquids contain a variety of ingredient combinations that should be assessed for human risk. One human lung-relevant testing platform with reasonable throughput, is human precision-cut lung slices (HuPCLS). HuPCLS are arguably the most complex non-animal model of the lung, retaining native architecture and immune-competent cells over multi-week culture periods. HuPCLS were exposed to three concentrations (0.1%, 0.5%, and 1.2%) of propylene glycol (PG; an E-vapor product constituent) continuously for 16-days. Exposure-effects were evaluated biochemically (WST-8 assay) and histologically (viability assessment of H&E stained slides). Positive control treatments consisted of 10 µM Phortress and 13 µM bleomycin.
Oral Irritation Assessment of Electronic Liquids Using an In Vitro Oral Testing Model
March 28, 2018While data are still being collected and analyzed, there were at least 1,300 accidental electronic liquid (e-liquid) exposures reported as of 2013. Deaths have occurred as a result of ingestion of e-liquid with the effects being attributed primarily to nicotine. The Food and Drug Administration (FDA) sought to regulate e-liquid through the Tobacco Control Act passed in 2009. In 2014, the FDA issued its “Deeming” proposals for public comments, which covered e-liquid manufacturing; the Final Rule giving the FDA authority to regulate e-liquids was released on May 5th, 2016. This study investigated the oral irritation of 3 different formulations of e-liquid using an in vitro time course assay in the reconstructed tissue model EpiOral™ (MatTek Corporation, Ashland, MA, USA). All products were from the same manufacturer, contained 1.2% nicotine and differed only in their flavorings.