What are Overmoulded Assemblies? Aseptic Fluid Transfer, Silicone, TPE and more

When I learned that 70% of product recalls in biopharma are caused by contamination risks, it became clear how important sterility is in biopharmaceutical applications. This got me thinking about the solutions that could prevent such costly setbacks. That’s when I came across the term "Aseptic Fluid Transfer" the process of moving sterile liquids between systems or containers without introducing contaminants (explained in detail later in this article) .

This process is gaining a lot of buzz in the biopharma industry, as minimizing the contamination is now the primary goal for every industry. The first product that commercially and technically fulfills this crucial need is the Overmoulded assembly.

What are Overmoulded Assemblies?

Overmoulded assemblies are components created by molding a secondary material over base substrate, such as tubing or connectors. Silicone and Thermo-Plastic Elastomers (TPE) are the most commonly used materials due to their flexibility, durability, and exceptional biocompatibility. These assemblies provide a seamless and integrated solution that minimizes the risk of leakage and contamination, making them ideal for aseptic fluid transfer in biopharma applications.

Why you should know about Overmoulded assemblies.

Any breach in sterility can lead to contamination, which may result in costly product recalls, regulatory non-compliance, or even serious health risks to patients. Contaminated products might need to be discarded, causing significant financial losses and production delays. In severe cases, contaminated biopharmaceuticals can lead to adverse patient reactions, resulting in legal liabilities and reputational damage.

The Properties that Make TPE and Silicone the only option for Overmoulding.

1. Traditionally, in assemblies, plastic connectors, nylon clamps, have been used in fluid transfer systems. However, these have been proven to leak and contaminate if not properly sealed. Overmoulded assemblies, on the other hand, use a single material composition, typically silicone or TPE.
2. Lesser risk of extractables and leachables: Technically, The homogeneity of these materials significantly reduces the risk of extractable and leachable, substances that can leach into the product from the materials used in the fluid transfer system.
3. Studies and research papers: Silicone and TPE have been extensively studied and are known for their minimal interaction with biopharmaceutical products. Their exceptional biocompatibility ensures that they do not introduce unwanted impurities into the system, preserving the integrity of the final product.
4. Comfortable Validation Process: The use of a single material streamlines the validation process, reducing the time and resources required for extensive testing on multiple materials. This efficiency not only accelerates the development timeline but also reduces costs.
5. Seamless Construction: Traditional connectors involve joints or seals, which are potential points of failure. If a joint is not properly sealed, it can lead to leaks, compromising the sterility of the fluid transfer process. Overmoulded assemblies eliminate this risk by providing a single, continuous piece without joints. This seamless construction ensures that fluids are transferred without exposure to external contaminants.
6. Maintenance of Integrity in the Internal Environment: The absence of joints also ensures that there are no disruptions in the internal environment of the tubing, providing a smooth and consistent flow of fluids. This is especially important in processes where maintaining specific environmental conditions is critical to the stability of the product.

Aseptic Connectors in Modern Biopharma Application:

While Overmoulded assemblies offer numerous advantages, it is also important to consider the role of aseptic connectors in biopharma applications. Aseptic connectors facilitate sterile connections between fluid pathways without compromising the system's sterility. These connectors are particularly valuable in processes requiring frequent changeovers or handling multiple fluids. Sterile aseptic connectors are engineered to maintain a sterile barrier during connection and disconnection, making them ideal for applications such as media preparation, cell culture, and final fill/finish operations.

Aseptic connectors are equipped with features like protective caps and sterile barriers that prevent contaminants from entering during the connection process. These connectors have become a modern standard in biopharma manufacturing.