Difference Vial vs. Dual-Chamber System

What are the differences between a product in a vial and in a dual-chamber syringe?

As a matter of principle, a pharmaceutical can be delivered in various application systems. The difference between the systems consists solely in the application. As a result of its ease-of-use, the dual-chamber syringe for example is more patient-friendly. It contains the active substance and the solution in two separate chambers which remain unmixed until shortly before administration. At this point, a simple "twist and push" forces the solution through into the front chamber, where it is mixed with the active substance. The patient benefits from the precision of dosing with the dual chamber system, time-saving handling as well as the fact that this system can be stored for longer (see also question “What are the advantages of a prefilled injection system?").