Documents & Resources
Human relevance of in vivo and in vitro skin irritation tests for hazard classification of pesticides
September 24, 2024Test methods to inform hazard characterization and labeling of pesticides to protect human health are typically conducted using laboratory animals, and for skin irritation/corrosion the rabbit Draize test is currently required by many regulatory agencies. Although the Draize test is generally regarded to provide protective classifications for human health, new approach methodologies (NAMs) have been developed that offer more human relevant models that circumvent the uncertainty associated with species differences that exist between rabbits and humans. (more…)
The Fibrotic Phenotype of Human Precision-Cut Lung Slices Is Maintained after Cryopreservation
September 24, 2024Human precision-cut lung slices (hPCLS) prepared from fibrotic lungs recapitulate the pathophysiological hallmarks of fibrosis. These hallmark features can also be induced by treating non-fibrotic hPCLS with a fibrotic cocktail (FC). As a result, the fibrotic and fibrosis-induced hPCLS are rapidly emerging as preferred models for disease modeling and drug discovery. However, current hPCLS models are limited by tissue viability in culture, as they are usually only viable for one week after harvesting. (more…)
Deriving a point of departure for assessing the skin sensitization risk of wearable device constituents with in vitro methods
September 24, 2024Wearable devices are in contact with the skin for extended periods. As such, the device constituents should be evaluated for their skin sensitization potential, and a Point of Departure (PoD) should be derived to conduct a proper risk assessment. Without historical in vivo data, the PoD must be derived with New Approach Methods (NAMs). To accomplish this, regression models trained on LLNA data that use data inputs from OECD-validated in vitro tests were used to derive a predicted EC3 value, the LLNA value used to classify skin sensitization potency, for three adhesive monomers (Isobornyl acrylate (IBOA), N, N- Dimethylacrylamide (NNDMA), and Acryloylmorpholine (ACMO) and one dye (Solvent Orange 60 (SO60)). (more…)
Approaches to Evaluation of Solvents for use in Photosafety Testing
March 20, 2024New Approach Methodologies (NAMs) are routinely used in photosafety testing to evaluate if a test compound has the potential to become more toxic upon exposure and subsequent exposure to light. Three such NAMs to address photosafety are the in chemico UV-Vis Assay, the cell-based 3T3 Neutral Red Uptake (NRU) Phototoxicity Test (PT), and the tissue-based Reconstructed human EpiDermis (RhE) Phototoxicity Test (PT), described under OECD Test Guidelines (TG) 101, 432, and 498, respectively. (more…)
Refinement and Optimization of the Photo-KeratinoSens™ Assay to Evaluate Photoallergy Potential
March 20, 2024Identification of test chemicals that have the potential to become more reactive, more toxic, or may become phototoxic upon application and subsequent exposure to sunlight is integral to photosafety testing. Several regulatory-based New Approach Methodologies (NAMs) are widely used in the evaluation of phototoxicity and skin sensitization potential. More recently, there has been an increased interest in ability to identify photoallergens. To this end, an innovative photo-KeratinoSens™ assay was established with addition of an irradiation exposure (5 J/cm2 of UVA) to the KeratinoSens™ Skin Sensitization Test (OECD TG 442D), as described in Tsujita-Inoue, et al. (2015). Twelve reference compounds were previously evaluated at IIVS under a protocol adapted from Tsujita-Inoue, et al. (2015), resulting in an accuracy of 58.3% (7/12 correctly predicted), with low sensitivity (50%, 5/10 positives correctly predicted) (Hilberer, et al., 2023).
Toxicity and Inflammatory Response to Common Magic Mouthwashes in a 3D Oral Reconstructed Tissue Model
November 8, 2023Magic Mouthwash is a general term describing oral rinses prescribed by a doctor for the treatment of pain, inflammation, or infection, commonly as a result of chemotherapy and radiation induced oral sores (oral mucositis). There is no set combination of ingredients for the preparation of a magic mouthwash, rather they are formulated for the individual needs of each patient, selecting from an array of various active ingredients. Although the ingredients most commonly used to formulate Magic Mouthwashes are considered safe as prescribed, the final formulations lack toxicity and inflammatory response data. (more…)
Safety Assessment of Monographed OTC Cold/Cough Medicine Using an In Vitro Testing Platform Based on Human Reconstructed Oral Tissues
November 8, 2023Over-the-counter (OTC) products are available to alleviate concurrent symptoms of colds and flu. They are primarily based on a combination of decongestants, antitussive and alpha adrenergic agonists, which are well-established pharmaceutical agents covered by U.S. monographs. Many of the active components of the OTC cough/cold drugs are bitter and must be masked using flavoring agents. Bayer internally employed a stringent safety testing program for OTC cough/cold medicine line extensions that require the products to be held in the mouth for a short period using an innovative testing platform based on reconstructed oral tissues. (more…)
The Importance of Supplier Qualification for Vendors of Materials Used in In Vitro Assays
November 7, 2023Pre-clinical assays, including in vitro assays, rely heavily on suppliers who provide essential products or services. In the current regulatory environment, the burden is placed on the users of these products or services to ensure that the methods employed at the suppliers' facilities meet a sufficient level of quality. Variable results for the same assay controls over time could indicate high lot-to-lot variability of the test system or of critical assay components. (more…)
Cryopreserved human precision-cut lung slices provide an immune competent pulmonary test system for “on-demand” use and long-term cultures
October 20, 2023Human precision-cut lung slices (hPCLS), considered a highly relevant ex vivo model of the lung, offer native architecture and cells of the lung tissue including respiratory parenchyma, small airways, and immune competent cells. However, the irregular availability of donor lungs has limited the accessibility of this system. As described here, thousands of hPCLS can be created from 1 lung, cryopreserved, and used “on demand” by applying slicing and cryopreservation methodology improvements. (more…)
A Laboratory Method to Measure Skin Surface Staining by Cigarette Smoke
October 20, 2023Exhaled or side-stream cigarette smoke (CS) may visually stain a consumer’s skin over time. Tobacco heating prod- ucts (THPs) and e-cigarettes (ECs) have reduced staining potential because they do not produce side-stream aerosols and their exhaled aerosols have significantly reduced levels of toxicants, particles and odour. Here we assess discolour- ation of porcine skin in vitro after exposure to particulate matter (PM) or aerosols from CS (3R4F), two THPs (glo and glo sens) and an EC (iSwitch Maxx). (more…)