Single-use solutions have been widely adopted on a global scale within the biopharmaceutical industry due to the many advantages and process improvements they offer.
Key applications for single-use assemblies include the creation of process fluid flow paths, buffer/product storage solutions and sampling systems on varying scales.
Most of these systems will start with either a bioprocess container or a tubing option and require the ability to connect to further pieces of equipment or additional single-use systems/manifolds.
In order to achieve this connectability, some form of connection needs to be selected — but with so many different connection types available, where should biopharmaceutical manufacturers start?
There are many different options available when embarking on the selection process. Consideration must be given to whether the connection type needs to be aseptic to provide quick and easy sterile connections, (even in non-sterile environments) or non-aseptic (to provide quick and easy non-sterile connections).
How do you choose the correct option?
The choice should be guided by the process itself — and the capability of the manufacturing plant should also be taken into account.
Key factors which will determine the correct choice of connection type include:
- Whether the connection is to be made inside or outside of a laminar airflow hood.
- Whether the connection needs to address any specific safety requirements.
- Process conditions and compatibility.
- Bioburden control.
- Experience of operatives.
- Suitability for purpose.
Only when these factors have been addressed can the end-user begin to fully specify the connection type required.
The Luer connector
The Luer connector is the simplest connector. It consists of both a male and female form, and the connection is made using a twist-lock action. These connections are suited to sample lines (with syringe connectivity) and low flow narrow-bore tubing applications and can be used within a laminar airflow hood to create aseptic connections.
However, there is a downside: potential misconnections can occur when they are not mated correctly.
Quick connectors such as the MPC, MPX or MPU from CPC (Colder Products Company) are similar to Luer connectors in that they can be used within a laminar airflow hood to create aseptic connections. They have the added security of a push-fit feature with a secure locking mechanism.
Triclamp (sanitary style) fittings can be used as connectors. While these are effective and secure connections, care must be taken to position the required o-ring seal within the connection prior to fixing the connection using an external clamp. The sheer size of the external clamp may make this an unsuitable method for connecting narrow bore or thin-walled tubing due to the weights involved and the potential for kinking/doubling of the attached tubing. Triclamp connections can be used within a laminar airflow hood to create aseptic connections.
Connections outside of a laminar airflow hood
Should aseptic connections be required to be made outside of a laminar airflow hood, two options are available, which both allow the connection of varying tube sizes:
Gendered aseptic connector
The first option for connecting aseptically in a non-aseptic environment would be to use a gendered aseptic connector, such as CPC AseptiQuik® gendered, which has both a male and female version. The benefit of using a gendered connection is that it can help by safeguarding which lines can be connected to certain points in the process; this helps to mitigate against human error and the accidental connection of the incorrect lines/equipment.
When designing single-use assemblies using a gendered connector approach, care must be taken to ensure that the correct male / female side is designed into each part; this in itself can also create some areas for error to creep in.
Genderless aseptic connector
Should the end-user not have any concerns over an accidental connection to the incorrect lines/equipment, or simply want to remove the error of male/female connector type which can creep in during design, there is the genderless aseptic connector, such as CPC AseptiQuik® genderless. These connectors take out the requirement for designing in the correct male/female orientation and can enable universal assemblies to be manufactured and connected with many other assembly/equipment types.
Both gendered aseptic connectors and genderless aseptic connectors operate via a mechanism that enables connection in non-sterile environments to be made possible. This is because of the use of proprietary seals which mate together before a protective seal is removed, thus keeping the process stream in its aseptic/sterile condition.
Connecting stainless steel and single-use
Should sterile connections between traditional stainless steel biopharmaceutical processing equipment and single-use assemblies be required, there is another option:
Steam to connectors, such as CPC Steam-Thru®, work by allowing steam to pass through the section connected to the stainless steel equipment. Once steamed and connected, a valve within the connector is manipulated, creating a sterile or aseptic flow path.
It is apparent that there are many connections capable of creating or maintaining an aseptic/sterile environment, but without the correct process condition assessment, operator care or design considerations, biopharmaceutical manufacturers could be looking at a costly connection failure.
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This post was contributed by Graeme Proctor, product manager (single-use technologies), Parker Bioscience Filtration, United Kingdom.
Parker Bioscience Filtration specializes in automating and controlling single-use bioprocesses. By integrating sensory and automation technology into a process, a manufacturer can control the fluid more effectively, ensuring the quality of the final product. Visit www.parker.com/bioscience to find out more.