Design of Rapid Transfer Ports in Aseptic Isolators

The transfer of materials into confined manufacturing spaces is a very critical operation, especially in the case of an aseptic environment. Depending on the manufacturing step, the failure of containment might have detrimental consequences, from the disruption of the working schedule (repeat preparation activities) to the rejection of the ongoing batch and impact to the sterility assurance of the previous manufacture. This article will provide an overview of the technology systems that allow passage of materials through the sterile barrier without breaking it and some useful tips to design the rapid transfer port.

What is a rapid transfer port?

The rapid transfer port (RTP) is a 2-component system that allows transferring materials between two separated contained areas, in a sterile way without incurring in contamination from the surrounding environment.


The rapid transfer ports are composed of two main parts:

  • Alpha part: this part is anchored on the wall of the fixed contained area (for example the isolator wall). The Alpha part is equipped with a door that communicates both with the contained area (internal, sterile side) and with the surrounding environment (external, non-sterile side).

  • Beta part: this part is embedded in a mobile container. The Beta part is equipped with a door that communicates both with the container area (internal, sterile side) and with the surrounding environment (external, non-sterile side).

Before the transfer of material, the Beta part is docked into the Alpha part. The rotation of the Beta part allows the two doors to connect into a single mobile (Alpha/Beta) port. The ‘non-sterile’ side of the doors is therefore masked to protect the sterility of the transfer. Once the port is opened, the two sterile chambers communicate with each other and the transfer can take place.



Interlock features of the rapid transfer port

Due to the criticality of the operation and the detrimental consequences of sterile barrier failure, the rapid transfer port is endowed with an interlock system that prevents errors. The interlock system works in the following way:

  • The Alpha door cannot be opened if a Beta system is not present or is not perfectly connected. This ensures that the sterile environment of the isolator is protected.

  • Vice versa, the Beta door cannot be opened if the Alpha system is not present or is not perfectly connected. This ensures that the sterile environment of the container is protected.

  • The Beta container cannot be disconnected from the Alpha part unless the alpha/beta port is closed so that the two environments are isolated from the surrounding environment.

What is it used for?

In general, rapid transfer ports can be used for two main purposes: