The pharmaceutical industry waited many years for the finalisation and publication of Annex 1 of the EU GMP Guidelines, which was released at the end of August 2022. Anticipation surrounding the document was considerable, and it is now evident that Annex 1 has become an internationally accepted regulatory standard.
The guideline provides overarching principles for the design, operation, and control of facilities, equipment, systems, and procedures used in the manufacture of sterile medicinal products.
CCS and QRM are noted as key drivers in Annex 1. A consistent requirement for a CCS, together with the systematic application of Quality Risk Management (QRM), runs throughout the entire document. Within this framework, the CCS is defined as an integrated, end-to-end approach to sterile pharmaceutical manufacturing, detailing the measures necessary to reduce the risk of microbial, particulate, and pyrogenic contamination.
Prior to the implementation of the revised Annex 1, risk assessments were already commonly performed for most manufacturing steps. Tools such as Failure Mode and Effects Analysis (FMEA) were used to identify potential contamination sources and to define suitable mitigation actions. Manufacturing processes were subdivided into individual steps, each assessed for contamination hazards and evaluated to determine whether appropriate controls existed or needed to be introduced. It should also be noted that, from a regulatory standpoint, quality control activities are considered part of the manufacturing process. Consequently, the EU GMP Guidelines, including Annex 1, apply equally to quality control operations.
Isolators differ fundamentally from RABS by providing a fully closed and rigid physical separation
Isolator technology fully aligned with current regulatory expectations
Over the past two decades, isolator systems have firmly established themselves within the pharmaceutical industry as a proven technology for both sterile manufacturing and quality control. Annex 1 explicitly acknowledges this development in several sections and provides a clear recommendation for the use of barrier technologies, as they substantially enhance product protection against contamination risks arising from endotoxins/pyrogens, particles, and microorganisms introduced by personnel, materials, or the surrounding environment.
Preventing operator involvement in critical aseptic steps is recognised as a crucial measure for contamination prevention. For this reason, Annex 1 explicitly identifies barrier systems as the preferred technical solution and requires a clear scientific justification when alternative environmental concepts are applied.
Section 2.1 of GMP Annex 1:
The manufacture of sterile products is subject to special requirements in order to minimize risks of microbial, particulate, and endotoxin/pyrogen contamination. The following key areas should be considered:
- …The use of appropriate technologies (e.g. Restricted Access Barriers Systems (RABS), isolators…) should be considered to increase the protection of the product from potential extraneous sources of endotoxin/pyrogen, particulate and microbial contamination such as personnel, materials and the surrounding environment, and assist in the rapid detection of potential contaminants in the environment and the product.
Section 8.9 of GMP Annex 1:
Where possible, the use of equipment such as RABS, isolators …, should be considered in order to reduce the need for critical interventions into grade A and to minimize the risk of contamination…
Section 4.3 of GMP Annex 1:
Restricted Access Barrier Systems (RABS) or isolators are beneficial in assuring required conditions and minimizing microbial contamination associated with direct human interventions in the critical zone. Their use should be considered in the CCS. Any alternative approaches to the use of RABS or isolators should be justified.
As a result, barrier technology—characterised by an aseptic background environment, physical separation of product handling from contamination sources, automated decontamination processes, unidirectional airflow, and defined pressure differentials—receives further regulatory endorsement.
When comparing barrier technologies, isolators differ fundamentally from RABS by providing a fully closed and rigid physical separation between the surrounding environment and the aseptic processing area. During operation, access to the isolator interior is restricted to glove ports and validated transfer systems. This design enables a substantially higher Sterility Assurance Level (SAL) compared with RABS-based solutions. Figure 1 illustrates the various environmental concepts alongside their associated SAL values. From a drug safety perspective, isolators represent the highest standard available for aseptic processing.
Figure 1: Environmental concepts and their associated SAL values
Robotic Systems
Annex 1 specifically highlights the consideration of robotic solutions in Sections 2.1 and 8.9. This recommendation reflects the overarching objective of minimising or eliminating direct human intervention in aseptic processes. Robotic systems have been widely used in pharmaceutical packaging for many years and are increasingly adopted in other production areas.
The logical extension of this trend is now commercially available in the form of gloveless isolator filling systems. These systems enable full automation of critical aseptic operations and provide the highest levels of safety, operational flexibility, and efficiency (see Figure 2).
Figure 2: A gloveless isolator
Isolators and CCS
As stated at the beginning, the CCS represents a central element of Annex 1. Consequently, it has a direct influence on isolators designed for aseptic applications. At an early stage, a risk-based assessment of the isolator system design should therefore be performed, including the installation and integration of equipment.
The system design provides the foundation for effective cleaning, with the objective of preventing potential particulate or microbiological contamination of sterile products and avoiding cross-contamination, particularly in multi-product operations.
In addition, the design is a key factor for subsequent surface decontamination using H₂O₂. It is also essential to assess whether robotic solutions can be implemented, as a high level of automation minimises manual interventions within the aseptic zone.
Conclusion
Annex 1 of the GMP guidelines clearly identifies barrier technologies—especially isolators—as the most appropriate background environment from a drug and patient safety perspective and explicitly advocates their use. The guideline even requires a formal justification when an alternative background environment that does not involve barrier technology is selected. As a result, Annex 1 has substantially strengthened the role of isolator technology, since isolators offer the highest level of environmental protection for aseptically manufactured sterile pharmaceutical products.