Online demonstrations and training available from Mecmesin technical sales engineers

Online test equipment and training demos


As more people are working from home to reduce travel, our technical sales engineers can provide online equipment demos or training sessions via web-based video calls.

If possible, send in your own samples and our sales team will be able to present your own products being tested.

Get in touch to discuss your requirements and to arrange an online demo or training session.

Break-loose and sustaining force tests of pre-filled drug cartridges to ISO 11608-3

9 July 2020


  • Software-controlled force tester
  • Custom-designed fixtures


  • Intuitive software to apply bespoke procedures or international standards
  • Versatile equipment can be used for multiple tests
  • Extensive reporting to log results for audit purposes


Mechanical pen injectors for delivering drugs, such as insulin, have found increasing acceptance over the traditional vial-and-syringe method.  Advances in pen design have made models increasingly user-friendly, allowing superior accuracy for delivering small doses together with patients reporting less injection pain. To validate new pen injector designs and maintain quality when they are mass-produced requires extensive testing.


One such test measures the force required to operate the pen injector when administering the drug.  It’s called the ‘break-loose and sustainability force’ and the test method is covered in ISO 11608-3 relating to finished containers for needle-based injection systems.  It’s important for patients because, if you are undergoing treatment requiring frequent, low-volume injections, you will need to be using pre-filled cartridges and you want them to administer the drug into your skin in a nice smooth manner.  Higher forces or jerky movement can lead to painful jabs of the needle.    



Mecmesin regularly works with leading multi-national manufacturers of pen injectors and pre-filled cartridges to supply easy-to-use and cost-effective force testers.  For performing the Break-loose and Sustainability Force Tests to ISO 11608-3, Mecmesin’s MultiTest 2.5-i test system is the ideal choice.  Controlled by Emperor software, it allows an operator to quickly and easily select the test method, load the cartridge into the custom-made jig and the tester does the rest.


A Mecmesin compression rod, connected to the tester’s loadcell, is lowered automatically until it detects the top of the cartridge stopper and sets a zero position.  From here, it applies an axial load to the cartridge plunger at a constant speed of 50mm/min over a travel distance of 40mm whilst simultaneously capturing force/displacement data on a graph.  


At the end of the test it automatically calculates the key parameters of:


• Break-loose force (also known as ‘breakout’ or ‘initiation’ force) as the first peak in force required to start the plunger moving

• Sustaining forces, including the average force to keep the plunger moving, and the min/max forces during this whole movement phase


The results are displayed as a table alongside the graph and classified according to the acceptance criteria per ISO 11608-3.  Results are automatically included in a test report or exported to the network for inclusion in other analysis software.


The same equipment is effortlessly used for the cartridge Leakage Test, where the tester applies a pre-determined force (based on the inner-diameter of the cartridge) for 60 seconds whilst the operator assess the liquid leakage from the cartridge. 


Test equipment

  • Software controlled force tester
  • Custom-designed fixtures for all syringe styles and sizes
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