Comparison of Flange Strength and Dimensional Variability in 1mL Long Syringe Systems made of Plastic and Glass

Harold Murray, Project Engineer, and Robert Froio, Intern, West Pharmaceutical Services, Inc.

Flange strength and dimensional variability are critical attributes when designing or selecting an auto-injector device to use in conjunction with a 1mL long syringe. Studies were performed to compare these attributes using Daikyo Crystal Zenith® (CZ) 1mL long syringes and glass 1mL long syringes.

The CZ 1mL long insert molded syringes demonstrated a significantly higher flange break force than glass 1mL long staked needle syringes samples from three separate glass vendors. The CZ 1mL long syringes required a force at least 72% and 125% higher respectively when tested using two different fixtures (drop-in and slide-in) than any of the glass syringes. The dimensional analysis demonstrated that the CZ 1mL long syringes consistently produced less variation and a lower standard deviation compared to glass 1mL long syringes for outside diameter (OD), inside diameter (ID), and wall thickness at each of three measurement points along the length of the barrel. The CZ 1mL long syringes had a standard deviation for OD measurements at least 38%, ID measurements at least 79%, and wall thickness at least 53% lower than glass 1mL long syringes.

Conclusions:

•         CZ 1mL long insert molded syringes demonstrate a significant increase in flange strength compared to glass 1mL long staked needle syringes, which can help reduce breakage recalls in the fill/finish process and in auto-injector devices.
•         CZ 1mL long syringes maintain consistent barrel ID throughout the length of the barrel.  The low dimensional variability of CZ syringes can help ensure consistent fit and functional performance within auto-injector devices.
•         CZ 1mL long syringes have a barrel ID with zero draft.

Daikyo Crystal Zenith® is a registered trademark of Daikyo Seiko, Ltd.
Daikyo Crystal Zenith® technology is licensed from Daikyo Seiko, Ltd.