Injectability of Glass and Polypropylene Syringes

Injectability of different types of syringes and media is an important characteristic that can be used to gain a better understanding of the physical properties that govern the injection process. One important parameter that can be used to determine injectability is the force it takes to push out the injection media during administration. Although the term injectability usually refers to this expulsion force, it can also include the dose preparation, pain during the procedure and its ergonomics as well as e.g. the needle-penetration force [1]. In this report we show how the expulsion force, consisting of an initial breakaway force (static friction) and a glide force (dynamic friction), can be determined using a novel test setup for the Universal Testing Machine Micro (UTM Micro). Additionally, the influences of different testing speeds, injection media, needle diameter and syringe material on the resulting forces are investigated.