CWA 18315:2025

Guidelines for Blood-Brain Barrier on-Chip Models for Drug Delivery Testing CWA 18315:2025

Scope

This CEN Workshop Agreement establishes standardized guidelines for developing and using BBB-on-chip models as a uniform platform for evaluating how drugs pass into the brain. By offering a common framework, the CWA seeks to decrease dependence on animal testing while enhancing the reproducibility, reliability, and comparability of results across different laboratories and research institutions. The document highlights five key areas essential for the successful deployment of BBB-on-chip technologies.
- Microfluidic design and operation: Setting parameters such as flow rate, shear stress, and perfusion conditions to maintain physiologically relevant barrier function.
- Cellular sources and culture strategies: Providing guidance on the use of primary versus iPSC-derived cells, along with best practices for endothelial co-culture systems, to enhance model robustness and biological relevance.
- Drug permeability assessment: Standardizing testing protocols, including thresholds for TEER and the calculation of permeability coefficients, to ensure consistent criteria for evaluating drug transport across the BBB.
- Model validation: Recommending the use of reference drugs and benchmarking methods based on established human BBB permeability data, ensuring that models can be compared and validated against known outcomes.
- Data management and reporting: Establishing clear guidelines for documenting experimental design, methodology, and results, thereby enhancing transparency, reproducibility, and inter-laboratory comparability.
Through these guidelines, the CWA aims to speed up the adoption of BBB-on-chip models in research, regulatory, and industrial environments, while endorsing the principles of the 3Rs in biomedical research.