Exploring the Invisible Bridge of Biopharmaceuticals — Pass-Through System

In the biopharmaceutical field, the cleanliness and safety of the production environment are directly linked to the quality of the pharmaceutical products. Today, let’s explore a critical technology in biopharmaceutical equipment:

Pass-Through System

It serves as the "Invisible Bridge" ensuring the cleanliness of the drug manufacturing environment.

I. What is a Pass-Through System?

In the biopharmaceutical field, a pass-through system is a transfer equipment installed between cleanrooms, either the same or different, used for the transfer of solutions, materials, tools, or samples. It ensures that cross-contamination between the cleanrooms is prevented during the transfer process through a dual-door design and efficient filtration system. At the same time, it prevents external contaminants from entering the clean areas, maintaining a highly clean production environment.

II. Core Functions of Pass-Through Systems

The core function of pass-through systems lies in addressing the risks of contamination, validation complexity, and space limitations in biopharmaceutical manufacturing through aseptic transfer design, cleanroom isolation, single-use components, and optimized flexible layout, while also enhancing production efficiency and compliance. The detailed content is as follows:

1. Achieving Aseptic Fluid Transfer and Reducing Cross-Contamination Risks

The pass-through system enables sterile fluid transfer between rooms of different cleanliness levels through stainless steel channels or single-use components. For example, in monoclonal antibody (mAb) production facilities, culture media can be directly transferred from the preparation area to bioreactors via the pass-through system, eliminating the risks of leakage or breakage associated with conventional container transfers. In vaccine production, inactivation of viral solutions must be conducted in separate areas based on viral inactivation kinetics. The pass-through system allows filtered transfer of inactivated viral solutions to dedicated inactivation containers in another area, preventing recontamination of the inactivated product and reducing the risk of inactivation failure due to protein aggregation.

The system’s single-use components (such as sleeves and end caps) eliminate the need for cleaning validation, further minimizing the risk of cross-contamination.

2. Isolation of Cleanrooms and Optimized Space Layout

Pass-through systems place product-contact parts in high-level clean zones , while the transmission, control, and maintenance parts are located in auxiliary zones. This physical isolation ensures that different cleanrooms do not interfere with each other. This design not only minimizes the size of cleanroom, reducing environmental maintenance costs, but also enhances facility maintenance efficiency by centralizing auxiliary areas (for example, around the facility) and shortening piping routes. For instance, the layout of a granulator or coating machine can limit noise and sources of contamination to the auxiliary zone, improving operational comfort in the process area.

3. Simplified Validation Process and Improved Compliance

Traditional fluid transfer processes require frequent cleaning and sterilization validation. However, the single-use components in the pass-through system (such as gaskets) are discarded after use, eliminating the need for cleaning validation and complying with GMP requirements. The system also supports standardized installation with complete documentation, ensuring traceability and compliance in the production process.

4. Flexibly Adapting to Production Needs

The Pass-through system can be adjusted according to the building structure (e.g., 5 cm standard wall panels or mezzanine walls), supports single or multiple pipelines, and can be customized to meet specific needs such as temperature control. For example, the Pass-through systems offered by Bio-Link provide different sizes of sleeves and connection methods, suitable for both new construction and renovation projects.

5. Improved Maintenance Convenience and Production Continuity

Maintenance tasks can be performed in the auxiliary zone without entering the high class cleanrooms, avoiding any disruption to the clean environment. For instance, maintenance of the mechanical parts of a fluidized bed dryer can be carried out in the auxiliary zone without affecting normal production in the process area, in compliance with Good Manufacturing Practices (GMP) requirements.

In addition, pass-through systems are also used for linking equipment between different workshops, data transmission, and the transfer of samples and reagents in certain biological laboratories to avoid external contamination. Pass-through systems are also widely used in food, cosmetics, and other industries to ensure high clean standards for the products.

III. Types of Pass-Through Systems

1. Same-Level Pass-Through System

When transmitting materials between the same class of cleanrooms, the material transfer tube passes through the sleeve and is secured with a clamp to ensure stability and prevent damage during the transfer. Additionally, this setup prevents air convection between the two rooms, ensuring both the safety of the materials and the cleanroom environment.

2. Cross-Level Pass-Through System

When transferring materials between cleanrooms of different classes, the material transfer tube passes through the sleeve, secured by clamp to ensure stability and prevent damage. Clean gas is introduced into the pass-through tube, which is then vented through exhaust holes. By adjusting the pressure-regulating valve, the exhaust gas pressure is maintained higher than the room pressure, preventing airflow exchange between rooms of different cleanliness levels and ensuring the stability of the cleanroom environment.

BioLink provides customized solutions for pass-through systems and related consumables. Please contact us for further inquiries.

BioLink Pass-Through Systems Ordering Information:

As the biopharmaceutical industry continues to raise its standards for cleanroom environments, pass-through systems are also evolving through continuous innovation. In the future, intelligent and multifunctional pass-through systems will become the industry standard, providing stronger assurance for drug safety and quality.

Though small in size, pass-through systems play an indispensable role in biopharmaceutical production. They silently safeguard each step of the manufacturing process, ensuring the safety and purity of every pharmaceutical product. Let’s give a round of applause to these Invisible Guardians!