Leak-free stopper for a syringe assembly having low breakloose and sustaining forces

• Main Authors: Kaliyamoorthy, Sathya, Cojocariu, Gheorghe, Smith, Chad, Addae-Mensah, Kweku, Giddes, Richard G, Prasad, Shishir, Kulshrestha, Ankur, Bonczynski, Gerald
• Format: Patent
• Language: English
• Published: 08.06.2017
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROMTHE BODY; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

A thermoplastic elastomer stopper that meets the desired material properties of a stopper for a syringe assembly is disclosed. The compression set of the thermoplastic elastomer stopper of the present disclosure is < 50% when measured at 25% compression for 22 hrs at 70 degree C. The hardness of the thermoplastic elastomer stopper of the present disclosure is 40-70 Shore A. The viscosity of a thermoplastic elastomer stopper of the present disclosure is > 70 Pa.s at 1,000 s shear rate, > 12.0 Pa.s at 10,000 sI shear rate, and > 3.0 Pa.s at 50,000 s- shear rate when measured using a capillary rheometer at 205 degree C (Die: Roundhole 20 mm length / 1 mm diameter / 180 degree inlet, Piston: d = 15 mm, and melting time = 7 min). The present non-lubricated stopper exhibits the required functional performance of a lubricated stopper.