Best Practice: Choosing Glass Or Polymer For Parenteral Packaging

Picking a material for parenteral containers is tricky. Polymer packaging has made inroads on glass, the long-time market leader, in recent years. Though glass’s superior barrier properties and regulatory ease mean it’s the top choice for drug manufacturers, the stability and flexible designs polymer allows have helped it increase its market share.

But the glass or polymer question doesn’t have one single answer-both materials possess their own advantages. Instead, the question drug manufacturers should be asking is, “Which material is best for our drug?” Consider the three Ps-product, process, and patient-as a best practice to ensure safe and cost-effective drug delivery.

Understand the product needs
What drug is being stored in this parenteral container? Different drugs have different requirements. The anticoagulant Heparin, for example, has been stored in glass prefilled syringes for decades without any major recalls or drug contamination cases, making glass an easy choice.

Compare that to dermal fillers-typically, highly viscous substances-that need to be stored in packaging that allows for consistent gliding force and an integrated Luer lock. In this case, polymer syringes have proven to be the material of choice.

Iron out the process requirements
Drug manufacturers, especially of biotech drugs, don’t want to waste any product, so eliminating broken containers or defects, as well as using low-waste filling lines, is paramount for packaging producers. Is glass or plastic the better solution?

On one hand, glass offers the advantage of being easily integrated into existing manufacturing lines, which can lead to a more streamlined filling process that is standardized for low waste; however, there is still risk of breakage. Plus, because glass has a long history in the parenteral container space, regulatory approval is straightforward.

Polymer containers, however, are break resistant. In addition, polymer prefilled syringes can have more accurate dimensions, and these tight tolerances lead to a more efficient, low-waste filling process. As polymer containers grow in market share, drug producers are tweaking their filling lines to easily process polymer-based cartridges and syringes.

Remember patient comfort and needs
Containers must be functional and easy to use, especially as the rate of drug delivery in home settings increases. The increased use of prefilled syringes in home settings is pushing drug producers to adopt packaging that combines high stability with low breakage and failure rates.

Generally speaking, glass is known for its low risk of drug interaction and heightened stability. However, polymer packaging has improved in this area. For example, the design flexibility of polymer enables a consistent gliding force that reduces the force of injection in dermal filler applications. Drug manufacturers must consider patient needs and safety before selecting a material for their parenteral containers.

Making the choice
Drug producers choosing between glass and polymer see that it isn’t an easy or quick choice; glass and polymer each have advantages and drawbacks, so there’s no outright winner in this debate. When weighing the benefits and drawbacks of each material, pharmaceutical developers should take a holistic approach for each use case.

Drug producers should consider a number of factors, including filling requirements and patient comfort, when selecting a material for parenteral containers. Follow the three P’s-product, process, and patient-to determine which material works best for a particular application.

About the author
Anil Kumar Busimi is director, Strategic Marketing & Innovation at Schott.