Rapid Transfer Ports – Smart Technologies for Filling and Sealing
Last updated: 21. April 2026
Rapid Transfer Ports (RTP) are mechanical interfaces for the low-contamination transfer of components. The ports enable the aseptic transfer of material or instruments into a closed container, such as an isolator. In this way, material can be transferred into or out of the controlled area while maintaining sterility requirements. Pharmaceutical companies use this system in the production of medicinal products or vaccines.
Material Transfer via RTP: Aseptic Material Transfer via Alpha-Beta Interface
Material transfer via Rapid Transfer Port (RTP) utilizes a closed system consisting of two parts: the Alpha-Beta system. This is based on the double-door principle (Double-Door Transfer System). Fundamentally: the two separate areas only come into contact when their sealing surfaces are coupled and closed.
The barrier is maintained during material transfer because a mechanical interlock closes the interface. This preserves the integrity of the partition wall and minimizes the risk of contamination. The technical system uses two complementary components for this purpose:
- The Alpha Port is permanently installed on the isolator.
- The Beta Container (or a Beta bag) forms the flexible component of the system as a mobile transfer module.
Only when these two parts are mechanically sealed and connected can the transfer channel be opened.
Aseptic Filling Lines from Rommelag
The bottelpack systems from Rommelag, manufactured in Germany, are used in aseptic filling. According to EU-GMP Annex 1, these systems enable a reduction of the cleanroom classification in the background (often Grade C) due to their closed system. The critical area of filling (Grade A) is kept spatially limited, which can influence operating costs and reduce contamination risks.
Castus RTP systems serve to move components into the sterile core of the plants. This process can be automated and take place under protection from external influences to support product quality.
Sterile Filling Lines for Ampoules
Rommelag equipment processes liquid media such as eye drops, inhalation solutions, or injectable preparations. Depending on the configuration and container size, these systems achieve an output of up to 35,000 units per hour with filling volumes between 0.1 and 60 milliliters. Thanks to the modular design and optimized mold tools, format changes are possible to keep downtime low.
Two Foundations for Material Transport
Controlled material transfer is based on the interaction of two essential processes:
- Rapid Transfer Ports (RTP) enable the exchange of the material to be processed in process engineering.
- Blow-Fill-Seal technology (BFS) produces the containers in a closed system, fills, and seals them immediately. This is designed to secure the process.
Blow-Fill-Seal Technology
Rommelag utilizes Blow-Fill-Seal technology (BFS) in aseptic filling. BFS links the steps of container production, filling, and sealing in a continuous, automated operation.
Blow – Forming the container In the BFS process, a thermoplastic polymer is extruded into a tube. Immediately after the mold closes, the container is formed using sterile air or vacuum support. Since the inside of the container is only created at the moment of forming and the material is processed at high temperatures, a separate container sterilization is usually not required.
Fill – Filling Special devices fill the container with the defined quantity of liquid or highly viscous media (such as gels or suspensions). The dosing systems operate according to specified precision standards.
Seal – Sealing Due to the residual heat of the material, the polymer fuses directly after filling and forms a hermetic seal. This sealing serves as protection against the ingress of germs or particles.
Material Selection and Types
Rommelag integrates Rapid Transfer Ports into aseptic BFS and isolator technologies. The RTPs consist of GMP-compliant materials.
Material Variants
- Stainless steel (316L): Material for high-purity pharmaceutical applications.
- High-density polyethylene (HDPE): Chemical-resistant and lightweight alternative for specific requirements.
- Plastic Beta Container: Solution for the transfer of defined substances.
- Aluminum Beta Container: Robust alternative to stainless steel.
- Silicone seals (FDA-compliant): For sealing between Alpha and Beta port.
Designs for RTP Systems
- Alpha Port Variants: Permanently installed ports or rotating Alpha ports to support the loading process.
- Beta Port Containers: Available in stainless steel, plastic, or aluminum.
- Automatic Systems: As Auto-Ports, these enable automated loading and unloading as well as seamless digital process monitoring (Audit Trail).
Useful Sizes
The systems are available in common industry standards with inner diameters of 105, 190, and 270 millimeters and are primarily designed for use in BFS isolator plants.