Joint poster with Lundbeck: Case study on Occupational Health and Safety
Assessing Skin Sensitizing Hazard of Drug Products and Active Pharmaceutical Ingredients using GARD®: New Approach Methodology in Occupational Health and Safety
Presented at 2025 SOT
Conclusion
In conclusion, the findings highlight NAMs like GARD®skin Dose-Response as useful tools for enhancing OHS and safety protocols in pharmaceutical manufacturing.
Abstract
Background and Purpose:
Skin sensitizers are chemicals capable of inducing hypersensitivity reactions, such as Allergic Contact Dermatitis (ACD). Identifying and characterizing these chemicals’ skin sensitizing potential is essential for limiting hazardous exposure. Significant efforts have been made in the scientific community to develop New Approach Methodologies (NAMs) to replace animal testing for skin sensitization. Internationally recognized test guidelines as well as integrated strategies have been developed, combining in vitro, in chemico, and in silico approaches for predicting skin sensitization potential.
While widely accepted in cosmetics and personal care, NAMs’ application in the pharmaceutical sector for product development and Occupational Health and Safety (OHS) is less prominent. The aim of this study is to demonstrate how NAMs, including the in vitro GARD® assay, combined with in silico data, can be used by the pharmaceutical industry to assess the skin sensitization potential of drug products and Active Pharmaceutical Ingredients (APIs) to take protective measures and improve occupational safety in production environments.
In this study, the drug product is an oral medicine used to treat mental health problems, and the two APIs are compounds that affects how dopamine works in the brain, helping with symptoms like hallucinations or delusions, and helps boost certain chemicals in the brain to improve mood and reduce feelings of depression, respectively.
Methods:
Following reports of allergic reactions in production and quality control, a drug product and two APIs A and B were assessed. The drug product contained approximately 0.5% of API A and 9.4% of API B. In silico predictions using Nexus Derek software identified all compounds as potential sensitizers. The in vitro assay GARDskin Dose-Response (GARDskin DR) was conducted to confirm these predictions.
The GARDskin method (OECD 442E) is an in vitro assay for assessment of chemical skin sensitizers. The method provides binary hazard identification of skin sensitizers by evaluation of transcriptional patterns of an endpoint-specific genomic biomarker signature, comprising 196 genes, referred to as the GARDskin Genomic Prediction Signature (GPS), in the SenzaCell cell line. Final classifications are provided by a machine-learning prediction algorithm in the form of Decision Values (DV), the sign of which is evaluated by the prediction model. Any test chemical with a positive mean DV is classified as a skin sensitizer. Conversely, any test chemical with a negative mean DV is classified as non-skin sensitizer.
GARDskin DR is an adaptation of the conventional GARDskin method, in which test chemicals are evaluated by the GARDskin prediction algorithm in an extended range of concentrations, to investigate the dose-response relationship between GARDskin DVs and test chemical concentration. It provides a quantitative estimation of sensitizing potency, referred to as cDV0, which corresponds to the lowest required dose able to generate a positive mean DV. The readouts can predict correlating LLNA EC3 values, which are traditionally used to measure the skin sensitizing potency of chemicals. Furthermore, it can predict human skin sensitizing potency NOEL and GHS/CLP classification (1A or 1B), all with high statistical significance.
Results:
All test items were identified as sensitizers by GARDskin DR with the following results:
• Drug product: cDV0 = 12.8 µg/ml. Predictions: LLNA EC3 = 7.63%, NOEL = 3108 µg/cm², GHS/CLP 1B.
• API A: cDV0 = 1.51 µg/ml. Predictions: LLNA EC3 = 1.08%, NOEL = 254 µg/cm², GHS/CLP 1A.
• API B: cDV0 = 1.77 µg/ml. Predictions: LLNA EC3 = 1.19%, NOEL = 315 µg/cm², GHS/CLP 1A.
Conclusions:
Both APIs were classified as strong sensitizers, while the drug product was classified as a weak sensitizer, reflecting the dilution effect of excipients. The GARDskin DR assay demonstrated a clear dose-dependent increase in DVs for all three test items, confirming their classification as skin sensitizers, with varying potencies.
Based on the test outcomes, recommendations were made to improve occupational safety in handling these sensitizers:
• Avoiding dust inhalation and skin/eye contact.
• Minimizing prolonged and/or repeated exposure.
• Using appropriate personal protective equipment (PPE).
• Removing contaminated clothing and washing it before reuse.
• Ensuring thorough hand washing after handling, during breaks, and at the end of each shift.
• Handling substances in closed systems with proper ventilation.
These findings highlight NAMs like GARDskin DR as useful tools for enhancing OHS and safety protocols in pharmaceutical manufacturing.
