The assessment of isolators as a barrier technology in the context of Annex 1 depends on various factors, including the manufacturing method, product characteristics and specific process and transfer risks. The choice of barrier technology used is a crucial step for pharmaceutical manufacturers to ensure the highest quality standards. Isolators, as an established barrier technology, provide a physical separation between the manufacturing process and the external environment. As a closed system, they enable comprehensive control over the process, which is particularly important in the production of sterile drugs. Isolators efficiently integrate multiple process steps and provide a flexible platform for complex manufacturing processes.