Local disinfection for drug delivery system

A method comprising:

• using a disinfection assembly disposed within a therapeutic substance delivery device, disinfecting a disinfection chamber that is defined between (i) a prefilled therapeutic substance reservoir and (ii) a sterile fluid path disposed within the therapeutic substance delivery device,
• the sterile fluid path comprising a needle at an upstream end of the sterile fluid path and an injection assembly at a downstream end of the sterile fluid path;
• and
• penetrating the disinfection chamber and then the reservoir with the needle,
• the disinfecting occurring (a) subsequently to the prefilled therapeutic substance reservoir being engaged with the therapeutic substance delivery device and (b) prior to the penetrating of the disinfection chamber and then the reservoir with the needle.