Serving as an indispensable aid in meeting and overcoming challenges are rapid transfer ports (RTPs).

Manufacturers of high-value products in life science industries share two common challenges as these products are moved into and out of cleanrooms, isolation chambers, and gloveboxes: 1) ensure that the purity or sterility of these products are not compromised and 2) make certain that any hazardous materials that are used or waste products that are created are handled safely and securely.

Serving as an indispensable aid in meeting and overcoming these challenges are rapid transfer ports (RTPs), which were developed as a way to provide safe, contained transfer of sterile or hazardous materials and waste as they are moved into and out of containment or isolation.

Over the years, Central Research Laboratories (CRL), for example, has created a full stable of RTP technologies that have been designed around the capabilities of an innovative double-door transfer system, which allows all types of materials to be rapidly transferred into and out of cleanroom, isolation chamber, or glovebox without breaking containment. This capability helps ensure product purity, quality, and integrity while helping to maintain an expected level of safety for operators.

This article looks at the ways that RTPs can help optimize product-handling operations in the life science industries.

Safe Environments

The double-door transfer system allows all types of materials to be rapidly transferred into and out of cleanrooms, isolation chambers, or gloveboxes without breaking containment. (Credit: Central Research Laboratories)

Building and maintaining a safe and secure work environment is a top-of-mind concern for all operators within the life science industry. This requires the creation and maintenance of highly reliable isolated environments that can protect against product contamination and exposure to potentially hazardous or dangerous materials.

Three operational areas within the life science realm are ideal for the use of RTPs:

  • Aseptic manufacturing: Keeping products free from contaminants is a priority in any aseptic-manufacturing process. From sterile active pharmaceutical ingredient (API) production and product formulation to the transfer of sterile liquids/components and aseptic-filling processes, sterility must be maintained at every stage with no chance that outside contaminants can infiltrate the production process.

  • Potent manufacturing: Ensuring product containment is essential when working with toxic materials, not only for the operator, but for the surrounding environment. Therefore, RTPs can play a significant role in keeping contaminants at bay during such high-value applications as high potency active pharmaceutical ingredient (HPAPI) production, the development of potent oral solid dose (POSD) pharmaceuticals, and the packaging and transport of finished APIs and POSDs.

  • Aseptic/potent manufacturing: This category combines the requirements of aseptic and potent manufacturing, with special emphasis placed on the production of sterile high potency active pharmaceutical ingredients (SHPAPI), biologics, radiopharmaceuticals, and highly concentrated formulations. RTPs can play a leading role in transferring these substances into and out of isolation safely through the prevention of exposure to toxic, hazardous, or dangerous materials.

The Role of RTPs

The first RTP model consisted of two main components: a stationary alpha flange mounted to the wall of a contained environment and the beta assembly, a mobile container, bag, or other process component that is attached to the alpha flange. (Credit: Central Research Laboratories)

RTPs have evolved through the diligent work of a design and engineering team that is constantly looking for ways to improve product performance. This innovative mindset has revealed itself again with CRL’s recent introduction of the new E Rapid Transfer Port, or ERTP (see the sidebar, “A New RTP Option”), which promises to make RTP operation easier than ever while maintaining the same product purity and containment capabilities that are the bedrock of life science production processes.

All RTP models feature the double door transfer system, but additional features have been developed over the years that give the technology more flexibility, including:

  • Handle designs that utilize minimal rotation to break the seal on the beta container, which simplifies operation while still maintaining a high safety level.

  • A streamlined interlock system with interchangeable three-bayonet and four-bayonet beta mount inserts that can be replaced without breaking containment.

  • Standard 316L stainless-steel body construction with three port-door options:

    • Stainless steel for use in strong chemical/radiation and some aseptic applications.

    • Polypropylene for use in pharmaceutical, chemical, and nuclear applications.

    • Liquid-transfer for use in sterile filling-line and fluid-transfer applications.

  • The elimination of pinch points on the handle, which minimizes glove damage.

  • The elimination of exposed fasteners that creates a smoother surface that enables easier cleaning.

  • Compatibility with various beta assembly options.

    Before the introduction of the new ERTP, two different iterations of CRL’s original RTP model incorporated some, if not all, of these features: the sterile liquid transfer port (SLTP) and the sterilizable rapid transfer port (SRTP).

  • Sterile liquid transfer port (SLTP): The patent-pending SLTP, which is a component within the company’s sterile liquid transfer system, helps enable efficient, safe, and contamination-free transfer of aseptic liquids from sterile product devices through a barrier wall and into a cleanroom or isolator. This design helps the SLTP satisfy ring of concern challenges where the alpha door and beta assembly meet, which is an area that is constantly at risk of becoming contaminated. The SLTP overcomes this challenge through its ability to allow the sealing surfaces to be heat sterilized. Other advanced features and benefits of the SLTP include:

    • A standard steam-in-place (SIP) cleaning process with a dedicated docking plate that enables proper beta flange placement during sterilization activities.

    • Polypropylene or stainless-steel protective collar at the ring of concern.

    • An alpha flange equipped with mechanical interlocks that help prevent improper port operation.

    • A product connection tube with inner surfaces polished to 15 μm and sloped to aid in drainage.

    • An extended polypropylene or stainless-steel alpha port door that accommodates longer product-connection tubes.

    • A single- or multi-connection beta flange with a condensate-drain connection.

    • Alpha and beta flange body construction of 316L stainless steel.

    • Silicone gasket seals.

    • Tri-clover fittings on product tubes for reusable, validatable, and rapid aseptic-hose connection and disconnection.

    • Testing and approval for use at hydrostatic pressures up to 3.4 bar (50 psi).

  • Sterilizable rapid transfer port (SRTP): The SRTP offers traditional double-door transfer system design and enhances it by featuring patented dry-heat sterilization technology. Unlike conventional UV-sterilization techniques, the dry-heat sterilization process eliminates concerns associated with contaminated seals that may result from inconsistent aseptic wiping or the shadowing and stacking of aseptic components. This makes SRTPs ideal for the transfer of components that require high sterility-assurance levels, such as stoppers, vials, and caps, into a sterile isolator or aseptic barrier system. This high sterility is achieved through the installation of an electric heater in the alpha flange at the intersection of the seals. This critical high-temperature zone is heated to 375 °F (190 °C) for a predetermined length of time after the alpha and beta flanges have been docked. Independent tests have shown that this dry-heat sterilization technique can result in up to a 6-log microbial reduction level at the sealing surfaces of the SRTP.

Other advanced features of the SRTP include:

  • 316L stainless-steel alpha flange with polypropylene or stainless-steel door.

  • Polypropylene or stainless-steel protective collar at the ring of concern.

  • Silicone gasket seals.

  • Automated port-door functions.

  • Automated protective collar.

  • Molded medical-grade polymer beta flange with various bag materials.

  • Automated loader system for alpha/beta flange decking.

RTPs are available in 105-, 190-, 270- and 350-mm sizes, with the measurement corresponding to the diameter of the alpha/beta assembly’s opening. Those sizes are also compatible with the various ancillary components that are available, with the exception of single-use beta bags, which are currently only available in a 190-mm configuration.


The life science industries have always been — and will continue to remain — critical in the global marketplace. Operators in these industries can only find true success, however, if they are able to safely and efficiently produce products that meet all standards for purity and consistency. Helping to achieve this goal are rapid transfer ports, which have proven for the past quarter-century to be reliable companions for those journeying through the life science industries. These RTPs have proven to provide the flexibility and reliability in these critical applications as they help maintain sterile and contamination-free workplaces around the globe.

This article is written by Rob Weber, Manager of Projects & Proposals for Central Research Laboratories (CRL), a DESTACO company. CRL is based in Red Wing, MN. Weber can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it.. For more information, visit