How They Are Made - Polymer-Based Containers for Parenteral Drugs

The manufacture of polymer containers for parenteral drug products differs from that of glass and elastomers and must combine the common manufacturing methods below to meet the needs of the pharmaceutical market.

Common methods for forming thermoplastic polymer components are:

• injection molding: process involves movement of melted polymer through a heated barrel and injection into a mold – upon cooling the component is released. This process is capable of producing high volumes ranging in size and shape from soda caps to fenders.
• blow molding: process involves movement of melted polymer though a heated barrel into a mold followed by blown air to force the polymer to conform to the mold with concomitant formation of a hollow interior – upon cooling the component is released. A common example is milk jugs.

Conical vials, syringes and cartridges comprising Daikyo Crystal Zenith^® cyclic olefin polymer can be produced with a standard injection molding process. But, to allow for release from an injection mold, a component cannot possess features such as an overhang or undercut, thus preventing critical features such as vial shoulder. Therefore, for standard Daikyo Crystal Zenith vials, a hybrid process is needed – one comprising both injection and blow aspects. For the hybrid process, melted polymer is injected into the mold around a core pin, creating a preform with the appropriate neck and flange dimensions. The remaining melted polymer around the core pin is then blown with air to form the complete vial. This hybrid method enables a traditional shape having the very tight tolerances of injection molding, in particular at the flange –minimizing variation at the crucial vial stopper interface and helping to ensure good container closure integrity.

West’s commitment to the safe and efficient delivery of drug products involves not only designing the right components, but also manufacturing them to rigorous standards. To learn more about West products, please visit the Knowledge Center or contact a Technical Account Representative.

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