Pre-filled Syringes: Advancing Efficiency & Accessibility
One of the significant advancements in the life sciences industry in recent years has been the advent of pre-sterilized, ready-to-use packaging. The process and sterility advantages of RTU containers have proved to be a difference maker for many pharmaceutical manufacturers. As segments of the liquid pharmaceutical market have continued to grow (patient-centered products like ATMPs and decentralized manufacturing operations come to mind), RTU containers have provided a feasible, scalable solution for many new and evolving parenteral products. Leaders like BD, Schott, West, and Stevanato have been at the forefront of many of the latest advancements in these containers, as there is an increasing selection of options that can be tailored to a product’s specific needs. One growing aspect of the RTU movement is the use of pre-filled syringes (PFS) due to both the simplicity and sterility assurance associated with the RTU approach, and the accessibility and accuracy of applications specific to pre-filled syringes.
When deciding on a container for your drug product, the application, limitations, cost, and full lifecycle of the product being dispensed should be considered. An initial area where pre-filled syringes are an ideal solution when compared to other containers like vials is dose accuracy. Vials often require overfill to account for possible product loss from the stopper and the device used to remove the product from the vial for the application. Pre-filled syringes cut out the transfer process with a staked or attachable needle. In an automated setting, this allows recipe-driven filling that’s precise to the specified dose. In the case of higher-value liquid pharmaceuticals, this can be combined with a zero-waste approach, including non-destructive in-process weight checks and efficient pump operations, ensuring there’s no product loss in the pump priming and calibration process.
The pre-filled syringe advantage is especially apparent in a patient care setting, where pre-filled syringes cut down substantially on steps from preparation to administration, with a 40 percent reduction in the overall process. Additionally, A 2023 systematic review of the literature found that pre-filled syringes reduce medical errors; Traditionally prepared syringes had an observed error rate of 10.4 percent, while pre-filled syringes had an error rate of 2.5 percent. It also improved drug waste compared to conventional methods by up to 80% in some cases and showed significant gains in preparation times. In terms of actual time saved, pre-filled syringes saved, on average, about six minutes per dose in preparation and administration when compared to traditional methods.
Shelf stability in these RTU delivery devices is also spotlighted as an added benefit; pre-filled syringes can last up to 3 years unopened, bypassing a large portion of preparation errors that account for the majority of drug waste within a healthcare setting.
Don’t Throw Stones at Glass Syringes
As pre-filled syringes are expected to see continued growth (some estimations have the PFSs market growing by as much as $4.04 billion by 2028), pertinent questions for manufacturers processing PFSs are what type of material to use as part of the container and what sort of injection features should be included. As breakthroughs happen and new drug products are discovered, the requirements of the container become more nuanced, and options become more configurable to operational parameters. The conventional material used in the manufacture of PFSs is glass. The technology is well understood across the industry from both a product-compatibility and production standpoint. That ubiquity is a net benefit as most fill-finish systems are designed with glass syringe processing in mind. There are also additional benefits of using glass PFSs, including:
- A long regulatory history with proven use
- Borosilicate glass containers are heat resistant and not sensitive to hydrolysis
- Robust supply chains
- Not as susceptible to the material effects of hydrogen peroxide and oxygen.
Glass does, however, have limitations. Glass PFSs can be highly breakable and can have a lower dimensional tolerance due to the way they are fabricated. Its composition makes a glass pre-filled syringe susceptible to issues like product interaction with silicone gel, which is used to coat the barrel in order for the plunger to move freely. There can also be instances of leaching and the presence of extractables. Additionally, the fabrication process of the staked needle could lead to tungsten residue shedding.
Polymer: A New Dimension of Flexibility and Durability
Due to the realities of glass containers and the specific needs of newer, patient-centered products, polymer plastic has emerged as an exciting avenue of growth. This category of pre-filled syringes is comprised of different types of polymers, including Cyclic Olefin Polymer (COP), Polycarbonate (PC), Polypropylene (PP), and Cyclic Olefin Copolymer (COC). The design benefit of this type of material is that they’re made via precise molding and offer tighter dimensional tolerances for better accuracy.
Additional benefits of polymer PFSs include:
- Absence of heavy metal ionization
- Significantly better durability when compared to glass
- Compatible with e-beam sterilization
- Design flexibility, including custom formats
Like glass, polymer syringes also have some limitations. Supply chains aren’t as robust for polymer container production. Additionally, the plastic used is more permeable and can be unsuitable for certain oil-based formations. Any fill-finish process of polymer syringes must also take into account handling for the containers, as the material is highly prone to scratches and blemishes. One of the key innovations of AST’s aseptic fill-finish systems is gentle scratch-free handling all the way through the line, whether processing syringes or other containers.
Fill-finish containers, like processes, should be selected and configured based on product requirements. While there’s no silver bullet, one-size-fits-all PFS solution, the flexibility and accessibility of this innovative subset of RTU packaging will only continue to expand. Learn how AST can help your organization find the ideal aseptic processing approach with our next-generation fill-finish technologies contact our experts today.
