Effect of vehicle on the in vitro penetration and metabolism of genistein and daidzein in ex vivo skin explants and the Phenion full-thickness skin model.

In a read-across assessment of the safety of genistein and daidzein in cosmetic products, additional information was required to account for differences in their systemic exposure after topical application in a typical body lotion formulation. Therefore, we measured the penetration and metabolism of two doses (3 and 30 nmoles/cm) of genistein and daidzein applied in ethanol and in a body formulation to fresh pig skin, fresh and frozen human skin, and PhenionFT models. Both chemicals readily penetrated all skin models when applied in ethanol.

Next-generation risk assessment read-across case study: application of a 10-step framework to derive a safe concentration of daidzein in a body lotion.

We performed an exposure-based Next Generation Risk Assessment case read-across study using New Approach Methodologies (NAMs) to determine the highest safe concentration of daidzein in a body lotion, based on its similarities with its structural analogue, genistein. Two assumptions were: (1) daidzein is a new chemical and its dietary intake omitted; (2) only data were used for daidzein, while and legacy data for genistein were considered. The 10-step tiered approach evaluating systemic toxicity included toxicokinetics NAMs: PBPK models and biokinetics measurements in cells used for toxicogenomics and toxicodynamic NAMs: pharmacology profiling (i.

Development of a non-target strategy for evaluation of potential biological effects of inhalable aerosols generated during purposeful room conditioning using an inhalation model.

Objectives: An integrated inhalation approach was outlined to estimate potential adverse acute inhalation effects of aerosols from commercial nebulizer applications used for purposeful room conditioning such as disinfection, scenting or others. Aerosol characterization, exposure estimation and evaluation of acute biological effects by inhalation were included to generate dose-response data, allowing for determination of lowest observable adverse effect levels (LOAELs). Correlation of these to estimates of human lung deposition was included for quantitative to extrapolation approach (QIVIVE) for acute effects during human exposure.

Incorporating integrated testing strategy (ITSv1) defined approach into read-across (RAx) in predicting skin sensitization potency: ITSv1-based RAx.

Recently, due to regulatory and ethical demands, new approach methodologies (NAMs), defined approaches (DAs), and read-across (RAx) have been used in the risk assessment of skin sensitization. Integrated testing strategy (ITS)v1 DA, adopted in OECD Guideline No. 497, can be used for skin sensitization potency categorization.