PT  - JOURNAL ARTICLE
AU  - Christina M Evans
AU  - Yusuf Oni
AU  - Daniel Paniagua
AU  - Jason Franck
AU  - Charles Dahlheim
AU  - Ankur Kulshrestha
TI  - Stopper Movement and Headspace (Air Bubble Size) Limitations for 2.25mL Prefilled Syringe
AID  - 10.5731/pdajpst.2022.012749
DP  - 2023 Jan 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - pdajpst.2022.012749
4099  - http://journal.pda.org/content/early/2023/08/14/pdajpst.2022.012749.short
4100  - http://journal.pda.org/content/early/2023/08/14/pdajpst.2022.012749.full
AB  - The Sterile Barrier is one of the most important aspects of the Container Closure Integrity (CCI) for a prefilled syringe (PFS or syringe). This crucial barrier enables the protection of the syringe contents from contamination. The plunger stopper (stopper) is naturally in a stationary position that is controlled by the static friction between the plunger stopper and the syringe barrel wall. When an applied force is greater than the static friction which is commonly known as the Break Loose force, the plunger stopper will move. This movement can occur when the pressure differential between the gaseous headspace inside the syringe and the external atmosphere is large enough that the force exerted on the stopper exceeds the Break Loose force of the syringe. This can occur during altitude or temperature changes incurred during aerial or mountainous transport. In such conditions, the stopper movement can further be increased if an air bubble is introduced between the liquid fill in the syringe and the stopper during the stoppering process. This paper, therefore, discusses the relationship between stopper movement and initial headspace (air bubble size/ABS) in a 2.25mL Type I glass syringe using theoretical and empirical approaches. The results showed the maximum initial headspace needed to enable CCI at specified altitudes and plunger stopper movements for the syringe-plunger stopper combination used in the study. Empirical data also indicated that CCI can be maintained for this syringe-plunger stopper combination with up to 9mm initial headspace at altitudes up to 17,000 feet.